The BaseTest Class

In PySys each test is a class which contains the methods needed to execute your test logic and then to validate the results against the expected behaviour to produce a final “outcome” for the test.

All test classes inherit (directly or indirectly) from the BaseTest class, which provides everything you need to create your own tests.

Implementing your test class

Each PySys test class must implement an execute method containing the main body of the test, and (usually) a validate method containing the assertions that check for the expected result. Sometimes you may also need to provide setup and/or cleanup functionality:

setup()	Contains setup actions to be executed before the test is executed.
execute()	The method tests implement to perform the test execution steps.
validate()	The method tests implement to perform assertions that check for the expected behaviour.
addCleanupFunction(fn[, ignoreErrors])	Registers a function that will be called as part of the cleanup of this object.

Taken together, the PySys setup() -> execute() -> validate() methods correspond to the common ‘Arrange, Act, Assert’ testing paradigm.

At the end of each test, PySys automatically terminates all processes it started, in the cleanup method. If any additional custom cleanup steps are required, these can be added by calling addCleanupFunction.

(For advanced users, it is also possible to customize the process of aborting a test run in response to a signal or Ctrl+C by overriding the handleRunnerAbort method`)

NB: Do not ever override the __init__ constructor of a test class; instead use setup for any initialization, which ensures orderly cleanup if an exception occurs during the setup process.

Test configuration

The input/output directories and other essential information about this test object and its parent project are can be accessed via instance attributes on self:

• self.input (str): Full path to the input directory of the testcase, which is where test-specific resources such as configuration files are stored. The directory is the main <testDir> for projects created from PySys 2.0 onwards, or <testdir>/Input for projects created earlier. The path can be customized in the pysysdirconfig at a project, directory (or even testcase) level.

  Here is an example of copying a configuration file template from the input directory:

  self.copy(self.input+'/serverconfig.xml', self.output, mappers=[lambda line: line.replace('@PORT@', str(myport))])
  

  When storing large text files in the input directory it is recommended to use compression; see pysys.basetest.BaseTest.unpackArchive for details of how to decompress input files.

  Do not use the self.input field as a way to locate other resources that are in directories above Input/ (since this will fail when the input directory is empty and using a version control system (e.g. git) that doesn’t commit empty directories). For other test resource locations the recommended approach is to use self.project.testRootDir, define a specific project property for the directory (if widely used), or if that’s not practical then use self.descriptor.testDir to get the test directory.

• self.output (str): Full path to the output directory of the testcase, which is the only location to which the test should write output files, temporary files and logs. The output directory is automatically created and cleaned of existing content before the test runs to ensure separate runs do not influence each other. There are separate output directories when a test is run for multiple cycles or in multiple modes. The directory is usually <testdir>/Output/<outdir> but the path can be customized in the testcase descriptor and the --outdir command line argument.

• self.reference (str): Full path to the reference directory of the testcase, which is where reference comparison files are stored (typically for use with assertDiff). The directory is usually <testdir>/Reference but the path can be customized in the testcase descriptor.

• self.log (logging.Logger): The Python Logger instance that should be used to record progress and status information. For example:

  self.log.info("Starting myserver on port %d", serverport)
  

• self.mode (pysys.config.descriptor.TestMode): The user-defined mode this test object is running. Tests can use this to modify how the test executed based upon the mode, for example to allow the test to run against either a mock or a real database. TestMode subclasses str so you can include this in situation where you need the name of the mode such as when recording performance result, and you can also use the .params attribute to access any parameters defined on the mode.

• self.testCycle (int): The cycle in which this test is running. Numbering starts from 1 in a multi-cycle test run. The special value of 0 is used to indicate that this is not part of a multi-cycle run.

• self.descriptor (pysys.config.descriptor.TestDescriptor): The descriptor contains information about this testcase such as the test id, groups and test type, and typically comes from the test’s pysystest.* file.

• self.runner (pysys.baserunner.BaseRunner): A reference to the singleton runner instance that’s responsible for orchestrating all the tests in this project. The runner is where any cross-test state can be held, for example if you want to have multiple tests share use of a single server, VM, or other resource.

• self.project (pysys.config.project.Project): A reference to the singleton project instance containing the configuration of this PySys test project as defined by pysysproject.xml. The project can be used to access information such as the project properties which are shared across all tests (e.g. for hosts and credentials).

• self.testStartTime (float): The time when this test object was constructed (as returned by time.time()).

• self.testPlugins (list[object]): A list of any configured test plugin instances. This allows plugins to access the functionality of other plugins if needed (for example looking them up by type in this list).

• self.disableCoverage (bool): Set this to True to request that no code coverage is generated for this test (even when code coverage has been enabled for the PySys run), for example because this is a time-sensitive or performance-measuring test. Typically this would be set in an individual testcase, or in the setup method of a BaseTest subclass based on groups in the self.descriptor that indicate what kind of test this is.

• self.disablePerformanceReporting (bool): Set this to True to request that no performance figures are recorded. For example you might dynamically set this to True when a test is using options such as profiling or code coverage that would make the results meaningless.

• self.isRunnerAborting (bool): Check this while performing long-running operations to ensure your test exits quickly and does not hang if PySys needs to abort the test run e.g. due to a keyboard interruption signal. Alternatively, consider using BaseTest.pollWait.

• self.isRunnerAbortingEvent (win32event.Event): A Windows event object that is signalled when isRunnerAborting changes to True, for use with win32event.WaitForMultipleObjects. Only available on Windows.

• self.isRunnerAbortingHandle (int): A linux file handle that receives a write when isRunnerAborting changes to True, for use with select.select. Only available on Linux. You should never read or write this handle, it is provided only for use with select.

• self.isCleanupInProgress (bool): Check this for advanced cases where you need different behaviour if the current test/runner is performing its post-execution cleanup phase.

Additional variables that affect only the behaviour of a single method are documented in the associated method.

There is also a field for each test plugin listed in the project configuration. Plugins provide additional functionality such as methods for starting and working with a particular language or tool. A test plugin is just a class with a method setup(self, testobj) (and no constructor arguments), that provides methods and fields for use by tests. Each test plugin listed in the project configuration with <test-plugin classname="..." alias="..."/> is instantiated for each BaseTest instance, and can be accessed using self.<alias> on the test object. If you are using a third party PySys test plugin, consult the documentation for the third party test plugin class to find out what methods and fields are available using self.<alias>.*.

If you wish to support test parameters that can be overridden on the command line using -Xkey=value, just add a static variable just after the `class MyClass(BaseTest): line containing the default value, and access it using self.key. If a new value for that key is specified with -Xkey=value, that value will be set as an attribute by the BaseTest constructor, with automatic conversion from string to the correct type if the default value is a bool/int/float.

Assertions and outcomes

assertThatGrep(file, grepRegex[, ...])	Perform a validation by using a regular expression to extract the first matching value from a text file and then check the extracted string value is correct using an assertThat conditionstring.
assertGrep(file[, _expr, _unused, contains, ...])	Perform a validation by checking for the presence or absence of a regular expression in the specified text file.
assertGrepOfGrep(file, grepRegex, expectedRegex)	Perform a validation by using a regular expression "(...)" group to extract the first matching value from a text file and then use a second regex to validate that the extracted value is as expected.
assertLineCount(file[, _expr, _unused, ...])	Perform a validation assert on the count of lines in a text file matching a specific regular expression.
assertDiff(file1[, file2, filedir1, ...])	Perform a validation by comparing the contents of two text files, typically a file from the output directory against a file in the <testdir>/Reference/ directory containing the expected output.
assertThat(conditionstring, ...)	Performs equality/range tests or any general-purpose validation by evaluating a Python eval() expression in the context of some named values.
assertLastGrep(file[, _expr, _unused, ...])	Perform a validation assert on a regular expression occurring in the last line of a text file.
assertOrderedGrep(file[, _exprList, ...])	Perform a validation assert on a list of regular expressions occurring in specified order in a text file.
assertPathExists(path[, exists, abortOnError])	Perform a validation that the specified file or directory path exists (or does not exist).
abort(outcome, outcomeReason[, callRecord])	Raise an AbortExecution exception with the specified outcome and reason, to abort the current test.
skipTest(outcomeReason[, callRecord])	Raise an AbortException that will set the test outcome to SKIPPED and ensure that the rest of the execute() and validate() methods do not execute.
addOutcome(outcome[, outcomeReason, ...])	Add a validation outcome (and optionally a reason string) to the validation list.
getOutcome()	Get the final outcome for this test, based on the precedence order defined in pysys.constants.OUTCOMES.
getOutcomeReason()	Get the reason string for the current overall outcome (if specified).
getOutcomeLocation()	Get the location in the Python source file where this outcome was added.
reportPerformanceResult(value, resultKey, unit)	Reports a new performance number to the configured performance reporters, with an associated unique string key that identifies it for comparison purposes.

PySys has a library of assertion methods that are great for typical system testing validation tasks such as checking log messages, diff’ing output files against a reference, and for more complex cases, evaluating arbitrary Python expressions. All these methods are designed to give a really clear outcome reason if the assertion fails. Note that by default assertion failures do not abort the test, so all the validation statements will be executed even if some early ones fail.

For example:

def validate(self):
        self.assertGrep('myserver.log', expr=' (ERROR|FATAL|WARN) .*', contains=False)

        self.assertThatGrep('myserver.log', r'Successfully authenticated user "([^"]*)"',
                "value == expected", expected='myuser')

        self.assertThat('actualNumberOfLogFiles == expected', actualNumberOfLogFiles__eval="len(glob.glob(self.output+'/myserver*.log'))", expected=3)

The available test outcomes are listed in pysys.constants.OUTCOMES.

There are some deprecated methods which we do not recommend using: assertEval, assertTrue, assertFalse (assertThat should be used instead of these).

Processes

startProcess(command, arguments[, environs, ...])	Start a process running in the foreground or background, and return the pysys.process.Process object.
startPython(arguments[, disableCoverage])	Start a Python process with the specified arguments.
getNextAvailableTCPPort([hosts, ...])	Allocate a free TCP port which can be used for starting a server on this machine.
allocateUniqueStdOutErr(processKey)	Allocate unique filenames of the form processKey[.n].out/.err which can be used for the startProcess stdouterr parameter.
createEnvirons([overrides, addToLibPath, ...])	Create a new customized dictionary of environment variables suitable for passing to startProcess()'s environs= argument.
getDefaultEnvirons([command])	Create a new dictionary of environment variables, suitable for passing to startProcess(), with a minimal clean set of environment variables for this platform, unaffected (as much as possible) by the environment that the tests are being run under.
signalProcess(process, signal[, abortOnError])	Send a signal to a running process.
stopProcess(process[, abortOnError])	Stops the specified process, if it is currently running.
writeProcess(process, data[, addNewLine])	Write binary data to the stdin of a process.
waitForBackgroundProcesses([includes, ...])	Wait for any running background processes to terminate, then check that all background processes completed with the expected exit status.
startProcessMonitor(process[, interval, ...])	Start a background thread to monitor process statistics such as memory and CPU usage.
stopProcessMonitor(monitor)	Request a process monitor to stop.

The most important part of a test’s execute method is starting the process(es) that you are testing. Always use the startProcess method for this (or a wrapper such as startPython) rather than os.system or subprocess, to ensure that PySys can cleanup all test processes at the end of the test.

This class also provides methods to dynamically allocate a free TCP server port, and to monitor the memory/CPU usage of the processes it starts.

Waiting

PySys provides a number of methods that can be used in your execute method to wait for operations to complete, of which the most commonly used is waitForGrep.

waitForGrep(file[, expr, condition, ...])	Wait for a regular expression line to be seen (one or more times) in a text file in the output directory (waitForGrep was formerly known as waitForSignal).
waitForFile(file[, filedir, timeout, ...])	Wait for a file to exist on disk.
waitForBackgroundProcesses([includes, ...])	Wait for any running background processes to terminate, then check that all background processes completed with the expected exit status.
waitProcess(process[, timeout, ...])	Wait for a background process to terminate.
waitForSocket(port[, host, timeout, ...])	Wait until it is possible to establish a socket connection to a server running on the specified local or remote port.
wait(interval)	Wait for a specified period of time, and log a message to indicate this is happening.
pollWait(secs)	Sleeps the current thread for the specified number of seconds, between polling/checking for some condition to be met.

Do not use wait unless there is no alternative, since it makes tests both slower and more fragile than they ought to be.

Files

The helper methods for common file I/O operations are:

copy(src, dest[, mappers, encoding, ...])	Copy a directory or a single text or binary file, optionally tranforming the contents by filtering each line through a list of mapping functions.
unpackArchive(archive[, dest, autoCleanup])	Unpacks the specified file(s) from an archive to a directory.
mkdir(path)	Create a directory, with recursive creation of any parent directories.
deleteDir(path, **kwargs)	Recursively delete the specified directory.
deleteFile(path, **kwargs)	Delete the specified file, with optional retries and ignoring of errors.
grep(path, expr[, encoding, reFlags, mappers])	Returns the first occurrence of a regular expression in the specified file, or raises an exception if not found.
grepOrNone(path, expr[, encoding, reFlags, ...])	Returns the first occurrence of a regular expression in the specified file, or None if not found.
grepAll(path, expr[, encoding, reFlags, ...])	Returns a list of all the occurrences of a regular expression in the specified file.
logFileContents(path[, includes, excludes, ...])	Logs some or all of the lines from the specified file.
listDirContents(path[, recurse])	Recursively scans the specified directory and returns a sorted list of the file/directory paths under it suitable for diffing.
write_text(file, text[, encoding])	Writes the specified characters to a file in the output directory.
getDefaultFileEncoding(file, **xargs)	Specifies what encoding should be used to read or write the specified text file.

To get the configured input/output directories for this test see Test configuration.

For additional file/directory helper functions such as support for loading JSON and properties files, see the pysys.utils.fileutils module.

Miscellaneous

compareVersions(v1, v2)	Compares two alphanumeric dotted version strings to see which is more recent.
logValueDiff([actual, expected, ...])	Logs the differences between two values in a human-friendly way, on multiple lines (as displayed by assertThat).
disableLogging()	Temporarily stops logging for the current thread.
createThreadPoolExecutor([maxWorkers])	Create a PySys-friendly instance of Python's ThreadPoolExecutor, configured with support for PySys loggers, cleanup, and a recommended default number of workers.
startBackgroundThread(name, target[, ...])	Start a new background thread that will invoke the specified target function.
pythonDocTest(pythonFile[, pythonPath, ...])	Execute the Python doctests that exist in the specified python file; adds a FAILED outcome if any do not pass.
startManualTester(file[, filedir, state, ...])	Start the manual tester, which provides a UI to guide a human through the tests needed to implement this testcase.
stopManualTester()	Stop the manual tester if running.
waitManualTester([timeout])	Wait for the manual tester to be stopped via user interaction.
getBoolProperty(propertyName[, default])	Get a True/False indicating whether the specified attribute is set on this object (typically as a result of specifying -X on the command line), or else from the project configuration.

All BaseTest members

class pysys.basetest.BaseTest(descriptor, outsubdir: str, runner)

Bases: pysys.process.user.ProcessUser

BaseTest is the base class of every individual PySys test class, and contains the methods needed to execute your test logic and then to validate the results against the expected behaviour.

Apart from the addOutcome method this class is not thread-safe, so if you need to access it from multiple threads be sure to add your own locking around use of its fields and methods, including any cleanup functions.

testStartTime

The time when this test object was constructed (as returned by time.time()).

setup()

Contains setup actions to be executed before the test is executed.

The setup method may be overridden by individual test classes, or (more commonly) in a custom BaseTest subclass that provides common functionality for multiple individual tests. However before implementing a custom BaseTest subclass with its own setup() method, consider whether the PySys concept of test plugins would meet your needs.

If you do override this method, be sure to call super(BASETEST_CLASS_HERE, self).setup() to allow the setup commands from the base test to run.

If setup throws an exception, the cleanup method will still be called, to clean up any resources that were already allocated.

execute()

The method tests implement to perform the test execution steps.

Raises

NotImplementedError – If this method was not implemented yet.

validate()

The method tests implement to perform assertions that check for the expected behaviour.

In some cases all of the required assertions (e.g. checking that a process ran without error etc) will have been performed in the execute method and so validate will be empty. However, where possible it is recommended to put assertions into the validate method for clarity, and so that the pysys run --validateOnly option can be used during test development.

cleanup()

Contains cleanup actions to be executed after the test’s execute and validate methods have completed.

The cleanup method automatically stops all processes that are still still running (assuming they were started with startProcess). It also stops all process monitors running in separate threads, and any instances of the manual tester user interface.

If any custom cleanup is required, use addCleanupFunction instead of overriding this method.

addResource(resource)

Add a resource which is owned by the test and therefore gets its __del__ method called when the test is cleaned up.

Deprecated

Please use addCleanupFunction instead of this function.

startProcessMonitor(process, interval=5, file=None, handlers=[], **pmargs)

Start a background thread to monitor process statistics such as memory and CPU usage.

All process monitors are automatically stopped on completion of the test by BaseTest.cleanup, but you may also wish to explicitly stop your process monitors by calling pysys.process.monitor.BaseProcessMonitor.stop before you begin shutting down processes at the end of a test to avoid unwanted spikes and noise in the last few samples of the data.

You can specify a file and/or a list of handlers. If you use file, a default pysys.process.monitor.ProcessMonitorTextFileHandler instance is created to produce tab-delimited lines with default columns specified by pysys.process.monitor.ProcessMonitorTextFileHandler.DEFAULT_COLUMNS. If you wish to customize this for an individual test create your own ProcessMonitorTextFileHandler instance and pass it to handlers instead. Additional default columns may be added in future releases.

Parameters

• process – The process handle returned from the startProcess method.

• interval – The polling interval in seconds between collection of monitoring statistics.

• file –

  The name of a tab separated values (.tsv) file to write to, for example ‘monitor-myprocess.tsv’.

  A default pysys.process.monitor.ProcessMonitorTextFileHandler instance is created if this parameter is specified, with default columns from pysys.process.monitor.ProcessMonitorTextFileHandler.DEFAULT_COLUMNS.

• handlers – A list of pysys.process.monitor.BaseProcessMonitorHandler instances (such as pysys.process.monitor.ProcessMonitorTextFileHandler), which will process monitoring data every polling interval. This can be used for recording results (for example in a file) or for dynamically analysing them and reporting problems.

• pmargs – Keyword arguments to allow advanced parameterization of the process monitor class, which will be passed to its constructor. It is an error to specify any parameters not supported by the process monitor class on each platform.

Returns

An object representing the process monitor (pysys.process.monitor.BaseProcessMonitor).

Return type

pysys.process.monitor.BaseProcessMonitor

stopProcessMonitor(monitor)

Request a process monitor to stop.

This method is deprecated - just call pysys.process.monitor.BaseProcessMonitor.stop directly instead.

Waits for the monitor to fully stop if possible, but does not throw an exception if it fails.

All process monitors are automatically stopped and joined during cleanup, however you may wish to explicitly stop your process monitors before you begin shutting down processes at the end of a test to avoid unwanted spikes and noise in the last few samples of the data.

Parameters

monitor – The process monitor handle returned from the startProcessMonitor method

startBackgroundThread(name, target, kwargsForTarget={})

Start a new background thread that will invoke the specified target function.

See also createThreadPoolExecutor.

The target function will be invoked with the specified keyword arguments, preceded by the special keyword arguments stopping and log. The stopping argument is a Python threading.Event instance that can be used to detect when the thread has been requested to terminate. It is recommended to use this event instead of time.sleep to avoid waiting when the thread is meant to be finishing.

Example usage:

class PySysTest(BaseTest):
        def dosomething(self, stopping, log, param1, pollingInterval):
                log.debug('Message from my thread')
                while not stopping.is_set():

                        # ... do stuff here

                        # sleep for pollingInterval, waking up if requested to stop; 
                        # (hint: ensure this wait time is small to retain 
                        # responsiveness to Ctrl+C interrupts)
                        if stopping.wait(pollingInterval): return

        def execute(self):
                t = self.startBackgroundThread('DoSomething1', self.dosomething, {'param1':True, 'pollingInterval':1.0})
                ...
                t.stop() # requests thread to stop but doesn't wait for it to stop
                t.join()

Note that BaseTest` is not thread-safe (apart from addOutcome, startProcess and the reading of fields like self.output that don’t change) so if you need to use its fields or methods from background threads, be sure to add your own locking to the foreground and background threads in your test, including any custom cleanup functions.

The BaseTest will stop and join all running background threads at the beginning of cleanup. If a thread doesn’t stop within the expected timeout period a constants.TIMEDOUT outcome will be appended. If a thread’s target function raises an Exception then a constants.BLOCKED outcome will be appended during cleanup or when it is joined.

Parameters

• name – A name for this thread that concisely describes its purpose. Should be unique within this test/owner instance. A prefix indicating the test/owner will be added to the provided name.

• target – The function or instance method that will be executed on the background thread. The function must accept a keyword argument named stopping in addition to whichever keyword arguments are specified in kwargsForTarget.

• kwargsForTarget – A dictionary of keyword arguments that will be passed to the target function.

Returns

A pysys.utils.threadutils.BackgroundThread instance wrapping the newly started thread.

Return type

pysys.utils.threadutils.BackgroundThread

startManualTester(file, filedir=None, state=11, timeout=1800)

Start the manual tester, which provides a UI to guide a human through the tests needed to implement this testcase.

The manual tester user interface (UI) is used to describe a series of manual steps to be performed to execute and validate a test. Only a single instance of the UI can be running at any given time, and can be run either in the FOREGROUND (method will not return until the UI is closed or the timeout occurs) or in the BACKGROUND (method will return straight away so automated actions may be performed concurrently). Should the UI be terminated due to expiry of the timeout, a TIMEDOUT outcome will be added to the outcome list. The UI can be stopped via the stopManualTester method. An instance of the UI not explicitly stopped within a test will automatically be stopped via the cleanup method of the BaseTest.

Parameters

• file – The name of the manual test xml input file

• filedir – The directory containing the manual test xml input file (defaults to the output subdirectory)

• state – Start the manual tester either in the FOREGROUND or BACKGROUND (defaults to FOREGROUND)

• timeout – The timeout period after which to termintate a manual tester running in the FOREGROUND

stopManualTester()

Stop the manual tester if running.

waitManualTester(timeout=1800)

Wait for the manual tester to be stopped via user interaction.

wait(interval)

Wait for a specified period of time, and log a message to indicate this is happening.

Tests that rely on waiting for arbitrary times usually take longer to execute than necessary, and are fragile if the timings or machine load changes, so wherever possible use a method like waitForGrep to wait for something specific instead.

See also pollWait which should be used when performing repeated polling to wait for a condition without logging.

Parameters

interval – The time interval in seconds to wait.

assertPathExists(path, exists=True, abortOnError=False)

Perform a validation that the specified file or directory path exists (or does not exist).

Parameters

• path – The path to be checked. This can be an absolute path or relative to the testcase output directory.

• exists – True if the path is asserted to exist, False if it should not.

• abortOnError – Set to True to make the test immediately abort if the assertion fails.

Returns

True if the assertion succeeds, False if a failure outcome was appended.

assertEval(evalstring, abortOnError=False, **formatparams)

Perform a validation by substituting named {} placeholder values into a Python expression such as {expected}=={actual} or 4 <= {actual} <= 10.

Deprecated:

Deprecated since 1.5.1 in favour of assertThat which is now significantly more powerful and should be used for new tests.

Example use:

self.assertEval('os.path.getsize({filename}) > {origFileSize}',         
        filename=self.output+'/file.txt', origFileSize=1000)

Parameters

• evalstring –

  a string that will be formatted using .format(...) with the specified parameters, and result in failure outcome if not true.

  Parameters should be specified using {name} syntax, and quoting is not required as string values are automatically escaped using repr. e.g. ‘os.path.size({filename}) > {origFileSize}'.

  Do not use an f-string instead of explicitly passing formatparams, as with an f-string this method will not know the names of the substituted parameters which makes the intention of the assertion harder to understand from looking at the test output.

  The global environment used for evaluation includes the os.path, math, sys, re, json, and locale standard Python modules, as well as the pysys module and the contents of the pysys.constants module, e.g. IS_WINDOWS, and also the BaseTest’s self variable.

• formatparams –

  Named parameters for the format string, which can be of any type. Use descriptive names for the parameters to produce an assertion message that makes it really clear what is being checked.

  String parameters will be automatically passed through repr() before being formatted, so there is no need to perform additional quoting or escaping of strings.

• abortOnError – Set to True to make the test immediately abort if the assertion fails. Unless abortOnError=True this method only throws an exception if the format string is invalid; failure to execute the eval(…) results in a BLOCKED outcome but no exception.

Returns

True if the assertion succeeds, False if a failure outcome was appended.

assertThat(conditionstring, *positional_arguments, **kwargs)

Performs equality/range tests or any general-purpose validation by evaluating a Python eval() expression in the context of some named values.

This method is designed to produce very clear and informative logging and failure reasons if the assertion is unsuccessful (using the logValueDiff method).

Example usage:

# Equality comparison of an 'actual' vs 'expected' message from when our server started; 
# note the use of a descriptive name for the 'actualXXX=' keyword to produce a nice clear message if it fails
self.assertThat("actualStartupMessage == expected", expected='Started successfully', actualStartupMessage=msg)

# This produces the self-describing log messages like: 
#   Assert that (actualStartupMessage == expected) with expected='Started successfully', actualStartupMessage='Started unsuccessfully' ... passed

# Always design tests to give clear messages if there's a failure. Here's an example of adding an extra 
# parameter (fromLogFile) that's not used in the condition string, to indicate which server we're testing here
self.assertThat('actualUser == expected', expected='myuser', actualUser=user, fromLogFile='server1.log')

# Any valid Python expression is permitted (not only equality testing):
self.assertThat("actualStartupMessage.endswith('successfully')", actualStartupMessage=msg)
self.assertThat("re.match(expected, actualStartupMessage)", expected=".* successfully", actualStartupMessage=msg)
self.assertThat("(0 <= actualValue < max) and type(actualValue)!=float", actualValue=v, max=100)

# Use ``is`` for comparisons to True/False/None as in Python ``==``/``!=`` don't always do what you'd 
# expect for these types. 
self.assertThat("actualValue is not None", actualValue=v)

This method is powerful enough for almost any validation that the other assert methods don’t handle, and by enforcing the discipline of naming values it generates self-describing log messages and outcome reasons to make it really obvious what is going on. For best results, make sure that your keyword= parameters have clear and unique names so it’s obvious how each assertThat() differs from the other ones, and ensure that all values you’re going to want to see are included as one of the named parameter values (rather than buried deep inside the main conditionstring).

The condition string is just a Python expression, which will be passed to eval() and can use any of the keyword= argument values passed to this method (but not the caller’s local variables). The evaluation is performed in a namespace that also includes the current BaseTest instance (self), some standard Python modules (os.path, math, sys, re, json, and locale), the pysys module, and the contents of the pysys.constants module, e.g. IS_WINDOWS. If necessary, symbols for additional modules can be imported dynamically using import_module(). For example:

self.assertThat("IS_WINDOWS or re.match(expected, actual)", actual="foo", expected="f.*")
self.assertThat("import_module('tarfile').is_tarfile(self.output+file) is False", file='/foo.zip')

Sometimes the differences between assertThat expressions are hard to describe in the parameter names themselves, and for these cases you can get self-describing behaviour with a parameter ending in the suffix __eval whose value is itself a Python expression to be evaluated, using any local variable in the namespace of the calling code, for example:

myDataStructure = ...
self.assertThat("actual == expected", actual__eval="myDataStructure['item1'][-1].getId()", expected="foo")
self.assertThat("actual == expected", actual__eval="myDataStructure['item2'][-1].getId()", expected="bar")
self.assertThat("actual == expected", actual__eval="myDataStructure['item3'][-1].getId()", expected="baz")

# Produces self-describing log messages like this:
# Assert that {actual == expected} with actual{=myDataStructure['item1'][-1].getId()} ="foo" expected="foo" ... passed
# Assert that {actual == expected} with actual{=myDataStructure['item2'][-1].getId()} ="bar" expected="bar" ... passed
# Assert that {actual == expected} with actual{=myDataStructure['item3'][-1].getId()} ="baZaar" expected="baz" ... failed [pysystest.py:123]
#       actual: 'baZaar'
#     expected: 'baz'
#                 ^

As shown above, when (at least) two named parameters are provided and the condition string is a simple comparison using exactly two of the parameters, additional lines are logged if the assertion fails, showing at what point the two arguments differ (based on finding the longest common substring). So it’s a good idea to include both the actual and expected value as named parameters rather than as literals inside the condition string.

Changed in version 1.5.1: The ability to pass named keyword= parameters was added in 1.5.1 (prior to that this method was deprecated).

Parameters

• conditionstring (str) –

  A string containing Python code that will be evaluated using eval() as a boolean expression, for example actualXXX == expected, where XXX is a brief description of what value is being tested.

  It’s best to put expected values into a separate named parameter (rather than using literals inside the conditionstring), since this will produce more informative messages if there is a failure.

  Do not be tempted to use a Python f-string here, as that would deprive this method of the opportunity to provide a self-describing message and outcome reason.

• **kwargs – All additional keyword arguments are treated as values which will be made available when evaluating the condition string. Any keyword ending in the special suffix __eval will be treated as a Python expression string (rather than a string literal) and will be be evaluated in a namespace containing the local variables of the calling code and any preceding named parameters.

• *positional_arguments – (deprecated) Unnamed positional arguments will be substituted into the condition string using the old % format string mechanism, before it is evaluated. This feature is deprecated as it provides poor diagnostic information, requires string parameters to be explicitly escaped using repr(), and only permits stringifiable data structures to be used by the conditionstring. Instead use named keyword= in all new tests.

• failureOutcome=FAILED – The outcome that will be added if the condition fails. For example you could set this to pysys.constants.BADPERF for a performance assertion. Added in PySys v2.1.

• abortOnError=False – Set to True to make the test immediately abort if the assertion fails. By default this method produces a BLOCKED output but does not throw if the eval(…) cannot be executed.

• assertMessage='' (str) – A high-level description of what the assertion is achieving, used in log messages and the outcome reason. For example “Check the startup logging”. Alternatively, to add some additional information to the default message message (e.g. which file/server it pertains to etc), just add the info as a string value with an extra keyword argument e.g. server="server1".

Returns

True if the assertion succeeds, False if a failure outcome was appended (and abortOnError=False).

logValueDiff(actual=None, expected=None, logFunction=None, stringsAlreadyEscaped=False, **namedvalues)

Logs the differences between two values in a human-friendly way, on multiple lines (as displayed by assertThat).

Special handling is provided for common types such as strings, lists and dicts (note that this isn’t intended for use with data structures whose string representation is too big to display on the console).

Parameters

• actual (obj) – The actual value. Alternatively, this parameter can be ignored and a value with a different key provided as a keyword argument instead.

• expected (obj) – The baseline/expected value from which a diff will be computed to the actual value. Alternatively, this parameter can be ignored and a value with a different key provided as a keyword argument instead.

• stringsAlreadyEscaped (bool) – Usually any str values will be quoted and escaped (possibly using repr()), however in cases where you want to compare values which have already been converted to strings using your own quoting rules this option can be used to avoid doubling up on the quotes and escaping.

• logFunction (function) – By default each line is logged at INFO level using log.info(), but an alternative log function with the same signature can be provided if desired.

assertTrue(expr, abortOnError=False, assertMessage=None)

Perform a validation assert on the supplied expression evaluating to true.

Deprecated

Use assertThat instead of this method, which produces clearer messages if the assertion fails.

If the supplied expression evaluates to true a PASSED outcome is added to the outcome list. Should the expression evaluate to false, a FAILED outcome is added.

Parameters

• expr – The expression, as a boolean, to check for the True | False value

• abortOnError – Set to True to make the test immediately abort if the assertion fails.

• assertMessage – Overrides the string used to describe this assertion in log messages and the outcome reason.

Returns

True if the assertion succeeds, False if a failure outcome was appended.

assertFalse(expr, abortOnError=False, assertMessage=None)

Perform a validation assert on the supplied expression evaluating to false.

Deprecated

Use assertThat instead of this method, which produces clearer messages if the assertion fails.

If the supplied expression evaluates to false a PASSED outcome is added to the outcome list. Should the expression evaluate to true, a FAILED outcome is added.

Parameters

• expr – The expression to check for the true | false value

• abortOnError – Set to True to make the test immediately abort if the assertion fails.

• assertMessage – Overrides the string used to describe this assertion in log messages and the outcome reason.

Returns

True if the assertion succeeds, False if a failure outcome was appended.

assertDiff(file1, file2=None, filedir1=None, filedir2=None, ignores=[], sort=False, replace=[], includes=[], encoding=None, abortOnError=False, assertMessage=None, stripWhitespace=None)

Perform a validation by comparing the contents of two text files, typically a file from the output directory against a file in the <testdir>/Reference/ directory containing the expected output.

Differences in line ending are always ignored, and depending on the value of stripWhitespace leading and trailing whitespace may also be ignored.

The files can be pre-processed prior to the comparison to either ignore particular lines, sort their constituent lines, replace matches to regular expressions in a line with an alternate value, or to only include particular lines. However, it is often easier to instead use copy to perform the transformations (e.g. stripping out timestamps, finding lines of interest etc) and then separately call assertDiff on the file generated by copy. This makes it easier to generate a suitable reference file and to diagnose test failures. For example:

self.assertDiff(self.copy('myfile.txt', 'myfile-processed.txt', mappers=[RegexReplace(RegexReplace.DATETIME_REGEX, '<timestamp>')])))

The above example shows a very compact form of assertDiff, which uses the fact that copy() returns the path of the destination file, and that there is no need to specify assertDiff’s file2 (reference) parameter if it’s the same basename as the first argument (just located in a different directory). In practice it’s very convenient to use the same basename for both the reference file and the output file it’s compared to.

Should the files after pre-processing be equivalent a PASSED outcome is added to the test outcome list, otherwise a FAILED outcome is added.

If you have any serialized dictionary/map data structures in the comparison files, or any lists that come from a directory listing, be really careful to ensure there is deterministic sorting of the keys/filenames, as by default the ordering is often subject to unpredictable changes when upgrading tools or switching between OSes, and you don’t want to have to update lots of testcases every time the sorting changes. If you are able to get the data into a Python data structure (e.g. by serializing from JSON), Python’s json.dump(..., sort_keys=True) can be a convenient way to produce a predictable order for dictionary keys.

If you have a large set of test reference files which need to be updated after a behaviour or output formatting change, you can use a special command line option which makes assertDiff overwrite the reference files with a copy of the actual comparison file in cases where the diff would otherwise fail. Use this feature with caution, since it overwrites reference files with no backup. In particular, make sure you have committed all reference files to version control before running the command, and the afterwards be sure to carefully check the resulting diff to make sure the changes were as expected before committing. To use this feature, run:

pysys.py run -XupdateDiffReferences

Parameters

• file1 (str) – The actual (or first) file to be compared; can be an absolute path or relative to the test output directory.

• file2 (str) – The expected/reference (or second) file to be compared; can be an absolute path or relative to the Reference directory. The default is for file2 to be the same basename as file1 (but located in the Reference/ directory).

• filedir1 (str) – The dirname of the first file (defaults to the testcase output subdirectory)

• filedir2 (str) – The dirname of the second file (defaults to the testcase reference directory)

• ignores (list[str]) – A list of regular expressions used to denote lines in the files which should be ignored

• sort (bool) – Boolean flag to indicate if the lines in the files should be sorted prior to the comparison

• list[(regexp:str,repl:str),...]replace – List of tuples of the form (‘regexpr’, ‘replacement’). For each regular expression in the list, any occurences in the files are replaced with the replacement value prior to the comparison being carried out. This is often useful to replace timestamps in logfiles etc.

• stripWhitespace (bool) – If True, every line has leading and trailing whitespace stripped before comparison, which means indentation differences and whether the file ends with a blank line do not affect the outcome. If the value is None, delegates to the value of the project property defaultAssertDiffStripWhitespace (which is True for old projects, but recommended to be False for new projects).

• includes (list[str]) – A list of regular expressions used to denote lines in the files which should be used in the comparison. Only lines which match an expression in the list are used for the comparison.

• encoding (str) – The encoding to use to open the file. The default value is None which indicates that the decision will be delegated to the getDefaultFileEncoding() method.

• abortOnError (bool) – Set to True to make the test immediately abort if the assertion fails.

• assertMessage (str) – An additional high-level description of what this assertion is checking, e.g. “Assert message contents match expected values”. Used in log messages and the outcome reason.

Returns

True if the assertion succeeds, False if a failure outcome was appended.

assertGrepOfGrep(file, grepRegex, expectedRegex, encoding=None, encodingReplaceOnError=False, reFlags=0, mappers=[], **kwargs)

Perform a validation by using a regular expression “(…)” group to extract the first matching value from a text file and then use a second regex to validate that the extracted value is as expected.

Using this method to separate out the extraction and validation stages is clearer and produces more easily debuggable messages than combining both into a single assertGrep. For example:

self.assertGrepOfGrep('myserver.log', r'Successfully authenticated user .*in ([^ ]+) seconds', r'[0-9.]+$')

This is equivalent to assertThatGrep with a conditionstring of ‘re.match(expectedRegex, value)’. For details on the command line arguments, see that method.

Regular expressions aren’t the solution for every problem, and for cases where you need to match a literal or check a value is within a range, use assertThatGrep instead.

New in version 2.2.

assertThatGrep(file, grepRegex, conditionstring='value == expected', encoding=None, encodingReplaceOnError=False, reFlags=0, mappers=[], **kwargsForAssertThat)

Perform a validation by using a regular expression to extract the first matching value from a text file and then check the extracted string value is correct using an assertThat conditionstring.

For example:

# This is the typical case - the string "value" is assigned to the first (...) regex group, and keyword parameters 
# (e.g. "expected=") are used to validate that the "value" is correct
self.assertThatGrep('myserver.log', r'Successfully authenticated user "([^"]*)"', 
        "value == expected", expected='myuser')

# In cases where you need multiple regex groups for matching purpose, name the one containing the value using (?P<value>...)
self.assertThatGrep('myserver.log', r'Successfully authenticated user "([^"]*)" in (?P<value>[^ ]+) seconds', 
        "0.0 <= float(value) <= 60.0")

When your validation on the extracted value is itself to be performed with another regular expression, separating out the extraction and validation stages is still clearer and produces more easily debuggable messages than combining both into a single assertGrep. You can use the assertGrepOfGrep method to save having to enter conditionstring="re.match(expectedRegex, value)":

self.assertGrepOfGrep('myserver.log', r'Successfully authenticated user ".*" in ([^ ]+) seconds', r'[0-9.]+$')

See also the assertGrepOfGrep method which is an alias for the above.

This method is implemented using grep and assertThat, so see those methods for more detailed information on the parameters.

New in version 1.6.0.

Parameters

• file – The name or relative/absolute path of the file to be searched.

• grepRegex (str) –

  The regular expression to use for extracting the value of interest from the file. Typically this will use a (...) regular expression group to identify the part of the expression containing the value; alternatively a single (?P<value>...) named group may be used.

  Only the first line matching this expression will be considered, so ensure the grepRegex should be “just specific enough” to uniquely identify the required line, but without duplicating the verification to be performed with the conditionstring assertion.

• conditionstring (str) –

  A string containing Python code that will be evaluated using eval() to validate that “value” is correct. For example value == expected.

  It’s best to put expected values into a separate named parameter (rather than using literals inside the conditionstring), since this will produce more informative messages if there is a failure.

  Do not be tempted to use a Python f-string here, as that would deprive PySys of the opportunity to provide a self-describing message and outcome reason.

• mappers (List[callable[str]->str]) –

  A list of filter functions that will be used to pre-process each line from the file (returning None if the line is to be filtered out). This provides a very powerful capability for filtering the file, for example pysys.mappers.IncludeLinesBetween provides the ability to filter in/out sections of a file.

  Do not share mapper instances across multiple tests or threads as this can cause race conditions.

• encoding (str) – The encoding to use to open the file. The default value is None which indicates that the decision will be delegated to the getDefaultFileEncoding() method.

• encodingReplaceOnError (bool) – Set to True to replace erroneous characters that are invalid in the expected encoding (with a backslash escape) rather than throwing an exception. Added in PySys 2.2.

• reFlags (int) –

  Zero or more flags controlling how the behaviour of regular expression matching, combined together using the | operator, for example reFlags=re.VERBOSE | re.IGNORECASE.

  For details see the re module in the Python standard library. Note that re.MULTILINE cannot be used because expressions are matched against one line at a time.

• abortOnError (bool) – Set to True to make the test immediately abort if the assertion fails. By default this method produces a BLOCKED output but does not throw if the eval(…) cannot be executed.

• assertMessage='' (str) – A high-level description of what the assertion is achieving, used in log messages and the outcome reason. For example “Check the startup logging”. Alternatively, to add some additional information to the default message message (e.g. which file/server it pertains to etc), just add the info as a string value with an extra keyword argument e.g. server="server1".

• **kwargs – All additional keyword arguments are treated as values which will be made available when evaluating the condition string. Any keyword ending in the special suffix __eval will be treated as a Python expression string (rather than a string literal) and will be be evaluated in a namespace containing the local variables of the calling code and any preceding named parameters.

Returns

True if the assertion succeeds, False if a failure outcome was appended (and abortOnError=False).

assertGrep(file, _expr=None, _unused=None, contains=True, ignores=None, literal=False, encoding=None, encodingReplaceOnError=False, abortOnError=False, assertMessage=None, reFlags=0, mappers=[], expr='', filedir=None)

Perform a validation by checking for the presence or absence of a regular expression in the specified text file.

The assertGrep method is good for checking in a log to confirm that something happened, or to check that there are no error messages.

Note that if your goal is to check that a value in the file matches some criteria, it is better to use assertThatGrep or assertGrepOfGrep instead of this function, as these methods indicate the intention more clearly, produce better messages on failure, and in the case of assertThatGrep also allow for more powerful matching using a full Python expression (e.g. numeric range checks, pre-processing strings to normalize case or path separators, etc).

When contains=True this method adds a PASSED outcome if found or a FAILED outcome if not found (except when where are named groups in the expression in which case BLOCKED is used to indicate that the return value is not valid). When contains=False this is inverted so a PASSED outcome is added if not found and FAILED if found.

For example:

self.assertGrep('myserver.log', r' ERROR .*', contains=False)

# If error messages may be accompanied by stack traces you can use a mapper to join them into the same line 
# so if your test fails, the outcome reason includes all the information. This also allows ignoring errors 
# based on the stack trace:
self.assertGrep('myserver.log', r' (ERROR|FATAL) .*', contains=False, 
        mappers=[pysys.mappers.JoinLines.JavaStackTrace()],     
        ignores=['Caused by: java.lang.RuntimeError: My expected exception'])

# In Python 3+, f-Strings can be used to substitute in parameters, including in-line escaping of regex literals:
# (but assertThatGrep is a better choice here)
self.assertGrep('myserver.log', f'Successfully authenticated user "{re.escape(username)}" in .* seconds[.]')

# If you need to use \ characters use a raw r'...' string to avoid the need for Python \ escaping in 
# addition to regex escaping. Square brackets are often the clearest way to escape regular expression 
# characters such as \ . and ()
self.assertGrep('myserver.log', r'c:[\]Foo[\]bar[.]txt')

# Alternatively when dealing with paths on different OSes, a convenient approach is to perform a replacement on the final expression
self.assertGrep('myserver.log', 'Checking for path: .*abc/def/ghi/jkl[.]txt'.replace('/', r'[/\\]'))

# The IncludeLinesBetween mapper is very useful if you want to grep within a subset of the lines:
self.assertGrep('myserver.log', r'MyClass', mappers=[
        pysys.mappers.IncludeLinesBetween('Error message.* - stack trace is:', stopBefore='^$'),
])

The behaviour of the regular expression can be controlled using reFlags=. For example, to perform case-insensitive matching and to use Python’s verbose regular expression syntax which permits whitespace and comments:

self.assertGrep('myserver.log', reFlags=re.VERBOSE | re.IGNORECASE, expr=r\"""
        in\   
        \d +  # the integral part
        \.    # the decimal point
        \d *  # some fractional digits
        \ seconds\. # in verbose regex mode we escape spaces with a slash
        \""")

Remember to escape regular expression special characters such as ., (, [, { and \ if you want them to be treated as literal values. If you have a regular expression string with backslashes, it’s best to use a ‘raw’ Python string so that you don’t need to double-escape them, e.g. self.assertGrep(..., expr=r'c:\\Foo\\filename\.txt').

If you want to search for a string that needs lots of regex escaping, a nice trick is to use a substitution string (containing only A-Z chars) for the regex special characters and pass everything else through re.escape:

self.assertGrep('myserver.log', re.escape(r'A"string[with \lots*] of crazy characters e.g. VALUE.').replace('VALUE', '(.*)'))

If you need to extract a string for further processing without performing an assertion and updating the test outcome, see the using grep instead.

Changed in version 1.5.1: The return value and reFlags were added in 1.5.1.

Parameters

• file – The name or relative/absolute path of the file to be searched.

• expr (str) –

  The regular expression to check for in the file (or a string literal if literal=True), for example " ERROR .*".

  Remember to escape regular expression special characters such as ., (, [, { and \ if you want them to be treated as literal values, or use the argument literal=True.

  If you wish to do something with the text inside the match you can use the re named group syntax (?P<groupName>...) to specify a name for parts of the regular expression.

  For contains=False matches, you should end the expr with ** if you wish to include just the matching text in the outcome failure reason. If contains=False and expr does not end with a * then the entire matching line will be included in the outcome failure reason.

• contains (bool) – Boolean flag to specify if the expression should or should not be seen in the file.

• ignores (list[str]) – Optional list of regular expressions that will be ignored when reading the file. Ignore expressions are applied after any mappers.

• mappers (List[callable[str]->str]) –

  A list of filter functions that will be used to pre-process each line from the file (returning None if the line is to be filtered out). This provides a very powerful capability for filtering the file, for example pysys.mappers.IncludeLinesBetween provides the ability to filter in/out sections of a file and pysys.mappers.JoinLines can combine related error lines such as stack trace to provide all the information in the test outcome reason.

  Mappers must always preserve the final \n of each line (if present).

  Do not share mapper instances across multiple tests or threads as this can cause race conditions.

  Added in PySys 1.6.0.

• literal (bool) – By default expr is treated as a regex, but set this to True to pass in a string literal instead.

• encoding (str) – The encoding to use to open the file. The default value is None which indicates that the decision will be delegated to the getDefaultFileEncoding() method.

• encodingReplaceOnError (bool) – Set to True to replace erroneous characters that are invalid in the expected encoding (with a backslash escape) rather than throwing an exception. Added in PySys 2.2.

• abortOnError (bool) – Set to True to make the test immediately abort if the assertion fails.

• assertMessage (str) – An additional high-level description of what this assertion is checking, e.g. “Check for expected error message”. Used in log messages and the outcome reason.

• filedir (str) – The directory of the file (defaults to the testcase output subdirectory); this is deprecated, as it’s simpler to just include the directory in the file parameter.

• reFlags (int) –

  Zero or more flags controlling how the behaviour of regular expression matching, combined together using the | operator, for example reFlags=re.VERBOSE | re.IGNORECASE.

  For details see the re module in the Python standard library. Note that re.MULTILINE cannot be used because expressions are matched against one line at a time. Added in PySys 1.5.1.

Returns

The re.Match object, or None if there was no match (note the return value is not affected by the contains=True/False parameter).

However if the expr contains any (?P<groupName>...) named groups, then a dict is returned containing dict(groupName: str, matchValue: str or None) (or an empty {} dict if there is no match) which allows the assertGrep result to be passed to assertThat for further checking (typically unpacked using the ** operator; see example above).

assertLastGrep(file, _expr='', _unused=None, contains=True, ignores=[], includes=[], encoding=None, abortOnError=False, assertMessage=None, reFlags=0, expr='', filedir=None)

Perform a validation assert on a regular expression occurring in the last line of a text file.

Rather than using this method, use grepAll with assertThat for better error messages and more maintainable tests, e.g. you can extract the last line of a file easily with self.grepAll(file, '.')[0].

When the contains input argument is set to true, this method will add a PASSED outcome to the test outcome list if the supplied regular expression is seen in the file; otherwise a FAILED outcome is added. Should contains be set to false, a PASSED outcome will only be added should the regular expression not be seen in the file.

Parameters

• file – The basename of the file used in the grep

• filedir – The dirname of the file (defaults to the testcase output subdirectory)

• expr – The regular expression to check for in the last line of the file

• contains – Boolean flag to denote if the expression should or should not be seen in the file

• ignores – A list of regular expressions used to denote lines in the file which should be ignored

• includes – A list of regular expressions used to denote lines in the file which should be used in the assertion.#

• encoding – The encoding to use to open the file. The default value is None which indicates that the decision will be delegated to the getDefaultFileEncoding() method.

• abortOnError – Set to True to make the test immediately abort if the assertion fails.

• assertMessage (str) – An additional high-level description of what this assertion is checking, e.g. “Assert error message is as expected”. Used in log messages and the outcome reason.

• reFlags (int) –

  Zero or more flags controlling how the behaviour of regular expression matching, combined together using the | operator, for example reFlags=re.VERBOSE | re.IGNORECASE.

  For details see the re module in the Python standard library. Note that re.MULTILINE cannot be used because expressions are matched against one line at a time. Added in PySys 1.5.1.

Returns

The re.Match object, or None if there was no match (note the return value is not affected by the contains=True/False parameter).

However if the expr contains any (?P<groupName>...) named groups, then a dict is returned containing dict(groupName: str, matchValue: str or None) (or an empty {} dict if there is no match) which allows the result to be passed to assertThat for further checking (typically unpacked using the ** operator; see assertGrep for a similar example).

assertOrderedGrep(file, _exprList=[], _unused=None, contains=True, encoding=None, abortOnError=False, assertMessage=None, reFlags=0, exprList=[], filedir=None)

Perform a validation assert on a list of regular expressions occurring in specified order in a text file.

When the contains input argument is set to true, this method will append a PASSED outcome to the test outcome list if the supplied regular expressions in the exprList are seen in the file in the order they appear in the list; otherwise a FAILED outcome is added. Should contains be set to false, a PASSED outcome will only be added should the regular expressions not be seen in the file in the order they appear in the list.

Warning: while this assertion method can be very convenient for checking the order of a small number of expressions, it becomes unwieldy when the number of expressions grows beyond a handful, and this is definitely not the best tool for the job if what you’re doing is really about checking that a subset of data from an output file matches expectations. For that use case, it’s better to do a filtered copy() of the file to remove prefixes (e.g. timestamps) and lines that are not important, and then use assertDiff to check the extracted text matches expectations. This approach makes it easier to write tests, and crucially makes it much easier to figure out what went wrong if they fail.

Similarly, if you need to check that an expression appears between two other lines (e.g. for a start/end of section) this method will not give you a reliable way to do that if there’s a chance the section markers could appear more than once in the file, so instead use the filtered copy() approach described above, or use assertGrep with a pysys.mappers.IncludeLinesBetween mapper.

Parameters

• file – The basename of the file used in the ordered grep

• filedir – The dirname of the file (defaults to the testcase output subdirectory)

• exprList – A list of regular expressions which should occur in the file in the order they appear in the list

• contains – Boolean flag to denote if the expressions should or should not be seen in the file in the order specified

• encoding – The encoding to use to open the file. The default value is None which indicates that the decision will be delegated to the getDefaultFileEncoding() method.

• abortOnError – Set to True to make the test immediately abort if the assertion fails.

• assertMessage (str) – An additional high-level description of what this assertion is checking, e.g. “Assert error messages are as expected”. Used in log messages and the outcome reason.

• reFlags (int) –

  Zero or more flags controlling how the behaviour of regular expression matching, combined together using the | operator, for example reFlags=re.VERBOSE | re.IGNORECASE.

  For details see the re module in the Python standard library. Note that re.MULTILINE cannot be used because expressions are matched against one line at a time. Added in PySys 1.5.1.

Returns

True if the assertion succeeds, False if a failure outcome was appended.

assertLineCount(file, _expr='', _unused=None, condition='>=1', ignores=None, encoding=None, abortOnError=False, assertMessage=None, reFlags=0, expr='', filedir=None, mappers=[])

Perform a validation assert on the count of lines in a text file matching a specific regular expression.

This method will add a PASSED outcome to the outcome list if the number of lines in the file matching the specified regular expression evaluate to true when evaluated against the supplied condition.

Parameters

• file – The basename of the file used in the line count

• filedir – The dirname of the file (defaults to the testcase output subdirectory)

• expr – The regular expression string used to match a line of the file

• condition – The condition to be met for the number of lines matching the regular expression

• ignores – A list of regular expressions that will cause lines to be excluded from the count. Ignore expressions are applied after any mappers.

• encoding – The encoding to use to open the file. The default value is None which indicates that the decision will be delegated to the getDefaultFileEncoding() method.

• mappers (List[callable[str]->str]) –

  A list of filter functions that will be used to pre-process each line from the file (returning None if the line is to be filtered out). This provides a very powerful capability for filtering the file, for example pysys.mappers.IncludeLinesBetween provides the ability to filter in/out sections of a file and pysys.mappers.JoinLines can combine related error lines such as stack trace to provide all the information in the test outcome reason.

  Mappers must always preserve the final \n of each line (if present).

  Do not share mapper instances across multiple tests or threads as this can cause race conditions.

  Added in PySys 2.0.

• abortOnError – Set to True to make the test immediately abort if the assertion fails.

• assertMessage (str) – An additional high-level description of what this assertion is checking, e.g. “Assert all messages received”. Used in log messages and the outcome reason.

• reFlags (int) –

  Zero or more flags controlling how the behaviour of regular expression matching, combined together using the | operator, for example reFlags=re.VERBOSE | re.IGNORECASE.

  For details see the re module in the Python standard library. Note that re.MULTILINE cannot be used because expressions are matched against one line at a time. Added in PySys 1.5.1.

Returns

True if the assertion succeeds, False if a failure outcome was appended.

reportPerformanceResult(value, resultKey, unit, toleranceStdDevs=None, resultDetails=None)

Reports a new performance number to the configured performance reporters, with an associated unique string key that identifies it for comparison purposes.

Where possible it is better to report the rate at which an operation can be performed (e.g. throughput) rather than the total time taken, since this allows the number of iterations to be increased without affecting historical comparisons. For example:

self.reportPerformanceResult(int(iterations)/float(calctime), 
        'Fibonacci sequence calculation rate', '/s'))

If your test runs in multiple modes, make sure you include some information about the mode in the resultKey:

self.reportPerformanceResult(int(iterations)/float(calctime), 
        'Fibonacci sequence calculation rate using %s' % self.mode, '/s', 
        resultDetails=[('mode',self.mode)])

While use of standard units such as ‘/s’, ‘s’ or ‘ns’ (nano-seconds) is recommended, custom units can be provided when needed using pysys.perf.api.PerformanceUnit:

self.reportPerformanceResult(int(iterations)/float(calctime)/1000, 
        'Fibonacci sequence calculation rate using %s with different units' % self.mode, 
        unit=PerformanceUnit('kilo_fibonacci/s', biggerIsBetter=True))

If the current test is executed with unusual options (e.g. enabling a profiler or code coverage) that would invalidate performance numbers, you can set self.disablePerformanceReporting = True to prevent reportPerformanceResult calls from doing anything.

Parameters

• value – The numeric value to be reported. If a str is provided, it will be converted to a float.

• resultKey – A unique string that fully identifies what was measured, which will be used to compare results from different test runs. For example “HTTP transport message sending throughput using with 3 connections in SSL mode”. The resultKey must be unique across all test cases and modes. It should be fully self-describing (without the need to look up extra information such as the associated testId). Do not include the test id or units in the resultKey string. It must be stable across different runs, so cannot contain process identifiers, date/times or other numbers that will vary. If possible resultKeys should be written so that related results will be together when all performance results are sorted by resultKey, which usually means putting general information near the start of the string and specifics (throughput/latency, sending/receiving) towards the end of the string. It should be as concise as possible (given the above).

• unit – Identifies the unit the value is measured in, including whether bigger numbers are better or worse (used to determine improvement or regression). Must be an instance of pysys.perf.api.PerformanceUnit. In most cases, use pysys.perf.api.PerformanceUnit.SECONDS (e.g. for latency) or pysys.perf.api.PerformanceUnit.PER_SECOND (e.g. for throughput); the string literals ‘s’ and ‘/s’ can be used as a shorthand for those PerformanceUnit instances.

• toleranceStdDevs – (optional) A float that indicates how many standard deviations away from the mean a result needs to be to be considered a regression.

• resultDetails – (optional) A dictionary of detailed information about this specific result and/or test that should be recorded together with the result, for example detailed information about what mode or versions the test is measuring. Note this is result-specific, unlike the global “run details” shared across all tests in this PySys execution, which can be customized with a runner plugin. If no resultDetails are specified explicitly then parameters from the test’s mode will be used if present.

abort(outcome, outcomeReason, callRecord=None)

Raise an AbortExecution exception with the specified outcome and reason, to abort the current test.

See also skipTest.

Parameters

• outcome –

  The outcome, which will NOT override any existing outcomes previously recorded, unless the abort outcome is a non-failure (such as SKIPPED). If you want overriding behaviour for failure outcomes, instead of this function use:

  self.addOutcome(outcome, outcomeReason, abortOnError=True, override=True)
  

• outcomeReason – A string summarizing the reason for the outcome.

Changed in version 2.2: Previous outcomes are no longer overridden when aborting.

addCleanupFunction(fn, ignoreErrors=False)

Registers a function that will be called as part of the cleanup of this object.

Cleanup functions should have no arguments, and are invoked in reverse order with the most recently added first (LIFO), and before the automatic termination of any remaining processes associated with this object.

Typical cleanup tasks are to cleanly shutdown processes (which is sometimes necessary to obtain code coverage information), and to (attempt to) delete large files/directories created by the test:

self.addCleanupFunction(lambda: self.cleanlyShutdownMyProcess(params))
self.addCleanupFunction(lambda: self.deleteDir('my-large-dir'), ignoreErrors=True)
self.addCleanupFunction(lambda: self.deleteFile('my-large-file.log'), ignoreErrors=True)

Parameters

• fn (Callable[]) – The cleanup function.

• ignoreErrors (bool) – By default, errors from cleanup functions will result in a test failure; set this to True to log them but not produce a test failure. This parameter was added in 1.6.0.

addOutcome(outcome, outcomeReason='', printReason=True, abortOnError=False, callRecord=None, override=False)

Add a validation outcome (and optionally a reason string) to the validation list.

The method provides the ability to add a validation outcome to the internal data structure storing the list of validation outcomes. Multiple validations may be performed, the current supported validation outcomes of which are described in Assertions and outcomes.

The outcomes are considered to have a precedence order, as defined by the order of the outcomes listed above. Thus a pysys.constants.BLOCKED outcome has a higher precedence than a pysys.constants.PASSED outcome. The outcomes are defined in pysys.constants.

This method is thread-safe.

Although this method exists on all subclasses of pysys.process.user.ProcessUser, in practice only pysys.basetest.BaseTest subclasses actually do anything with the resulting outcome.

Parameters

• outcome (pysys.constants.Outcome) – The outcome to add, e.g. pysys.constants.FAILED.

• outcomeReason (str) – A string summarizing the reason for the outcome, for example “Grep on x.log contains ‘ERROR: server failed’”.

• printReason (bool) – If True the specified outcomeReason will be printed

• abortOnError (bool) – If true abort the test on any error outcome. This should usually be set to False for assertions, or the configured self.defaultAbortOnError setting (typically True) for operations that involve waiting.

• callRecord (list[str]) – An array of strings of the form absolutepath:lineno indicating the call stack that lead to this outcome. This will be appended to the log output for better test triage.

• override (bool) – Remove any existing test outcomes when adding this one, ensuring that this outcome is the one and only one reported even if an existing outcome has higher precedence.

allocateUniqueStdOutErr(processKey)

Allocate unique filenames of the form processKey[.n].out/.err which can be used for the startProcess stdouterr parameter.

The first time this is called it will return names like ('outdir/myprocess.out', 'outdir/myprocess.err'), the second time it will return ('outdir/myprocess.1.out', 'outdir/myprocess.1.err'), then ('outdir/myprocess.2.out', 'outdir/myprocess.2.err') etc.

Parameters

processKey (str) – A user-defined identifier that will form the prefix onto which [.n].out is appended

Returns

A STDOUTERR_TUPLE named tuple of (stdout, stderr), where each is an absolute path.

Return type

STDOUTERR_TUPLE

static compareVersions(v1, v2)

Compares two alphanumeric dotted version strings to see which is more recent.

Example usage:

if self.compareVersions(thisversion, '1.2.alpha-3') > 0:
        ... # thisversion is newer than 1.2.alpha-3 

The comparison algorithm ignores case, and normalizes separators ./-/_ so that '1.alpha2'=='1Alpha2'. Any string components are compared lexicographically with other strings, and compared to numbers strings are always considered greater.

>>> ProcessUser.compareVersions('10-alpha5.dev10', '10alpha-5-dEv_10') == 0 # normalization of case and separators
True

>>> ProcessUser.compareVersions(b'1....alpha.2', u'1Alpha2') == 0 # ascii byte and unicode strings both supported
True

>>> ProcessUser.compareVersions('1.2.0', '1.2')
0

>>> ProcessUser.compareVersions('1.02', '1.2')
0

>>> ProcessUser().compareVersions('1.2.3', '1.2') > 0
True

>>> ProcessUser.compareVersions('1.2', '1.2.3')
-1

>>> ProcessUser.compareVersions('10.2', '1.2')
1

>>> ProcessUser.compareVersions('1.2.text', '1.2.0') # letters are > numbers
1

>>> ProcessUser.compareVersions('1.2.text', '1.2') # letters are > numbers 
1

>>> ProcessUser.compareVersions('10.2alpha1', '10.2alpha')
1

>>> ProcessUser.compareVersions('10.2dev', '10.2alpha') # letters are compared lexicographically
1

>>> ProcessUser.compareVersions('', '')
0

>>> ProcessUser.compareVersions('1', '')
1

Parameters

• v1 – A string containing a version number, with any number of components.

• v2 – A string containing a version number, with any number of components.

Returns

an integer > 0 if v1>v2, an integer < 0 if v1<v2, or 0 if they are semantically the same.

copy(src, dest, mappers=[], encoding=None, symlinks=False, ignoreIf=None, skipMappersIf=None, overwrite=None)

Copy a directory or a single text or binary file, optionally tranforming the contents by filtering each line through a list of mapping functions.

If any pysys.mappers are provided, the file is copied in text mode and each mapper is given the chance to modify or omit each line, or even reorder the lines of the file. If no mappers are provided, the file is copied in binary mode.

For example:

self.copy('output-raw.txt', 'output-processed.txt', encoding='utf-8', 
        mappers=[
                lambda line: None if ('Timestamp: ' in line) else line, 
                lambda line: line.replace('foo', 'bar'), 
                pysys.mappers.IncludeLinesBetween('Error message .*:', stopBefore='^$'),
                pysys.mappers.RegexReplace(pysys.mappers.RegexReplace.DATETIME_REGEX, '<timestamp>'),
        ])

In addition to the file contents the attributes such as modification time and executable permission will be copied where possible.

This function is useful for creating a modified version of an output file that’s more suitable for later validation steps such as diff-ing, and also for copying required files from the input to the output directory.

It can also be used for copying a whole directory, similar to shutil.copytree but with the advantages of support for long paths on Windows, better error safety, and that relative paths are evaluated relative to the self.output directory (which is both convenient, and safer than shutil’s evaluation relative to the current working directory).

For example:

self.copy('src.txt', 'dest.txt')  # copies to outputdir/dest.txt
self.copy('src.txt', self.output) # copies to outputdir/src.txt, since self.output is an existing directory
self.copy('src.txt', 'foo/')      # copies to outputdir/foo/src.txt since destination ends with a slash
self.copy('srcdirname', 'foo/')   # copies to outputdir/foo/srcdirname since destination ends with a slash

For more information about pre-defined mappers, see pysys.mappers. Custom mappers can be specified as simple functions or lambdas, however for advanced use cases you can additionally provide mapper.fileStarted([self,] srcPath, destPath, srcFile, destFile) and/or mapper.fileFinished(...) methods to allow stateful operations, or to perform extra read/write operations before lines are read/written. For example:

class CustomLineMapper(object):
        def fileStarted(self, srcPath, destPath, srcFile, destFile):
                self.src = os.path.basename(srcPath)

        def __call__(self, line):
                return '"'+self.src+'": '+line

        def fileFinished(self, srcPath, destPath, srcFile, destFile):
                destFile.write('\n' + 'footer added by CustomLineMapper')
self.copy('src.txt', 'dest.txt', mappers=[CustomLineMapper()])

Changed in version 1.6.0: Ability to copy directories was added, along with the overwrite=, symlinks=, ignoreIf= and skipMappersIf= arguments.

Parameters

• src (str) – The source filename or directory, which can be an absolute path, or a path relative to the self.output directory. Use src=self.input+'/myfile' if you wish to copy a file from the test input directory.

• dest (str) –

  The destination file or directory name, which can be an absolute path, or a path relative to the self.output directory. Destination file(s) are overwritten if the dest already exists.

  The dest and src can be the same for file copies (but not directory copies).

  As a convenience to avoid repeating the same text in the src and destination, if the dest ends with a slash, or the src is a file and the dest is an existing directory, the dest is taken as a parent directory into which the src will be copied in retaining its current name.

  It is best to avoid copies where the src dir already contains the dest (which would be recursive) such as copying the test dir (possibly configured as self.input) to destination self.output, however if this is attempted PySys will log a warning and copy everything else except the recursive part.

• overwrite (bool) – If True, source files will be allowed to overwrite destination files, if False an exception will be raised if a destination file already exists. By default overwrite=None which means it’s enabled for single file copy() but disabled for directory copies.

• mappers (List[callable[str]->str]) –

  A list of filter functions that will be applied, in order, to map each line from source to destination. Each function accepts a string for the current line as input and returns either a string to write or None if the line is to be omitted. Any None items in the mappers list will be ignored. Mappers must always preserve the final \n of each line (if present).

  See pysys.mappers for some useful predefined mappers such as pysys.mappers.IncludeLinesBetween, pysys.mappers.RegexReplace and pysys.mappers.SortLines.

  If present the mapper.fileStarted(...) and/or mapper.fileFinished(...) methods will be called on each mapper in the list at the start and end of each file; see above for an example.

  Do not share mapper instances across multiple tests or threads as this can cause race conditions.

• encoding (str) – The encoding to use to open the file (only used if mappers are provided; if not, it is opened in binary mode). The default value is None which indicates that the decision will be delegated to the getDefaultFileEncoding() method.

• symlinks (bool) – Set to True if symbolic links in the source tree should be represented as symbolic links in the destination (rather than just being copied).

• ignoreIf (callable[str]->bool) – A callable that accepts a source path and returns True if this file/directory should be omitted from a directory copy. For example: ignoreIf=lambda src: src.endswith(('.tmp', '.log')))

• skipMappersIf (callable[str]->bool) – A callable that accepts a source path and returns True if this file should be copied in binary mode (as if no mappers had been specified). For example: skipMappersIf=lambda src: not src.endswith(('.xml', '.properties')))

Return str

the absolute path of the destination file.

createEnvirons(overrides=None, addToLibPath=[], addToExePath=[], command=None, **kwargs)

Create a new customized dictionary of environment variables suitable for passing to startProcess()’s environs= argument.

As a starting point, this method uses the value returned by getDefaultEnvirons() for this command. See the documentation on that method for more details. If you don’t care about minimizing the risk of your local environment affecting the test processes you start, just use environs=os.environ to allow child processes to inherit the entire parent environment instead of using this method.

Parameters

• overrides – A dictionary of environment variables whose values will be used instead of any existing values. You can use os.getenv('VARNAME','') if you need to pass selected variables from the current process as part of the overrides list. If the value is set to None then any variable of this name will be deleted. Use unicode strings if possible (byte strings will be converted depending on the platform). A list of dictionaries can be specified, in which case the latest will override the earlier if there are any conflicts.

• addToLibPath – A path or list of paths to be prepended to the default value for the environment variable used to load libraries (or the value specified in overrides, if any), i.e. [DY]LD_LIBRARY_PATH on Unix or PATH on Windows. This is usually more convenient than adding it directly to overrides.

• addToExePath – A path or list of paths to be prepended to the default value for the environment variable used to locate executables (or the value specified in overrides, if any), i.e. PATH on both Unix and Windows. This is usually more convenient than adding it directly to overrides.

• command – If known, the full path of the executable for which a default environment is being created (passed to getDefaultEnvirons).

• kwargs – Overrides of this method should pass any additional kwargs down to the super implementation, to allow for future extensions.

Returns

A new dictionary containing the environment variables.

createThreadPoolExecutor(maxWorkers=None) → concurrent.futures.thread.ThreadPoolExecutor

Create a PySys-friendly instance of Python’s ThreadPoolExecutor, configured with support for PySys loggers, cleanup, and a recommended default number of workers.

During cleanup, the thread pool is shutdown, with any unstarted futures cancelled (requires Python 3.9+), and a wait until all in-progress futures have completed.

This is useful for tests that need to perform many latency-bound operations such as making HTTP requests. Do not use it for starting lots of processes in parallel and waiting for them, since that is more easily achieved using waitForBackgroundProcesses().

If you use submit (rather than map), then any exceptions during the submitted job will not be logged anywhere unless you you wait for the submitted job (or add an exception handler). Note that this class is not thread-safe (apart from addOutcome, startProcess and the reading of fields like self.output that don’t change) so if you need to use its fields or methods from background threads, be sure to add your own locking to the foreground and background threads in your test, including any custom cleanup functions.

Example usage:

tp = self.createThreadPoolExecutor()
results = tp.map(items, makeHTTPRequest)

# Or for more complex use cases:
submittedFutures = []
submittedFutures.append(tp.submit(...))
concurrent.futures.wait(submittedFutures)

New in version 2.2.

Parameters

maxWorkers (int) –

Overrides the maximum number of worker threads that can be created by this pool. Only override this if needed. The default maxWorkers is configured in self.threadPoolMaxWorkers and is currently set at 6 since a higher number might overload a machine (or Python, due to the GIL) if pools are used by many/all of the PySys workers/tests running in parallel. The default may change in future.

If overriding this value, use a small number of workers for Python-based logic that will hold the Python Global Interpreter Lock, or a larger/more scalable number of workers for heavily I/O-bound operations with little Python logic.

Returns

A concurrent.futures.ThreadPoolExecutor instance.

deleteDir(path, **kwargs)

Recursively delete the specified directory.

Does nothing if it does not exist. Raises an exception if the deletion fails.

Parameters

• path – The path to be deleted. This can be an absolute path or relative to the testcase output directory.

• kwargs – Any additional arguments such as retries and ignore_errors are passed to pysys.utils.fileutils.deletedir().

deleteFile(path, **kwargs)

Delete the specified file, with optional retries and ignoring of errors.

Does nothing if it does not exist. Raises an exception if the deletion fails.

Parameters

• path – The path to be deleted. This can be an absolute path or relative to the testcase output directory.

• kwargs – Any additional arguments such as retries and ignore_errors are passed to pysys.utils.fileutils.deletefile().

disableLogging()

Temporarily stops logging for the current thread.

For example:

with self.disableLogging():
        self.startProcess(...)

Note that this method will do nothing if the log level if pysys is run with -vDEBUG or -vdisabledLogging=DEBUG.

New in version 1.6.0.

getBoolProperty(propertyName, default=False)

Get a True/False indicating whether the specified attribute is set on this object (typically as a result of specifying -X on the command line), or else from the project configuration.

See also pysys.baserunner.getXArg() and pysys.config.project.Project.getProperty().

Parameters

propertyName – The name of a property set on the command line or project configuration.

getDefaultEnvirons(command=None, **kwargs)

Create a new dictionary of environment variables, suitable for passing to startProcess(), with a minimal clean set of environment variables for this platform, unaffected (as much as possible) by the environment that the tests are being run under.

This environment contains a minimal PATH/LD_LIBRARY_PATH but does not attempt to replicate the full set of default environment variables on each OS, and in particular it does not include any that identify the current username or home area. Additional environment variables can be added as needed with createEnvirons overrides. If you don’t care about minimizing the risk of your local environment affecting the test processes you start, just use environs=os.environ to allow child processes to inherit the entire parent environment.

The createEnvirons() and startProcess() methods use this as the basis for creating a new set of default environment variables.

If needed this method can be overridden in subclasses to add common environment variables for every process invoked by startProcess, for example to enable options such as code coverage for Java/Python/etc. This is also a good place to customize behaviour for different operating systems.

Some features of this method can be configured by setting project properties:

• defaultEnvirons.ENV_KEY: if any properties with this prefix are defined, an environment variable with the ENV_KEY is set by this method (unless the property value is empty). For example, to set a default JVM heap size for all processes with the JAVA_TOOL_OPTIONS environment variable you could set defaultEnvirons.JAVA_TOOL_OPTIONS = -Xmx512M.

• defaultEnvironsDefaultLang: if set to a value such as en_US.UTF-8 the specified value is set for the LANG= variable on Unix; otherwise, the LANG variable is not set (which might result in use of the legacy POSIX/C encoding).

• defaultEnvironsTempDir: if set the expression will be passed to Python eval() and used to set the OS-specific temp directory environment variables. A typical value is self.output.

• defaultEnvironsLegacyMode: set to true to enable compatibility mode which keeps the behaviour the same as PySys v1.1, 1.2 and 1.3, namely using a completely empty default environment on Unix, and a copy of the entire parent environment on Windows. This is not recommended unless you have a lot of legacy tests that cannot easily be changed to only set minimal required environment variables using createEnvirons().

Parameters

• command –

  If known, the full path of the executable for which a default environment is being created (when called from startProcess this is always set). This allows default environment variables to be customized for different process types e.g. Java, Python, etc.

  When using command=sys.executable to launch another copy of the current Python executable, extra items from this process’s path environment variables are added to the returned dictionary so that it can start correctly. On Unix-based systems this includes copying all of the load library path environment variable from the parent process.

• kwargs – Overrides of this method should pass any additional kwargs down to the super implementation, to allow for future extensions.

Returns

A new dictionary containing the environment variables.

getDefaultFileEncoding(file, **xargs)

Specifies what encoding should be used to read or write the specified text file. The default implementation for BaseTest delegates to the runner, which in turn gets its defaults from the pysyproject.xml configuration.

See pysys.process.user.ProcessUser.getDefaultFileEncoding for more details.

getExprFromFile(path, expr, groups=[1], returnAll=False, returnNoneIfMissing=False, mustExist=True, encoding=None, encodingReplaceOnError=False, reFlags=0, mappers=[])

Searches for a regular expression in the specified file, and returns it.

Use of this function is discouraged - consider using grep / grepOrNone / grepAll instead.

If the regex contains unnamed groups using (expr) syntax, the specified group is returned. If the expression is not found, an exception is raised, unless returnAll=True or returnNoneIfMissing=True. For example:

myKey = self.getExprFromFile('test.txt', r'myKey="(.*)"') # on a file containing 'myKey="foobar"' would return "foobar"
err = self.getExprFromFile('test.txt', r'ERROR .*') # on a file containing 'ERROR It went wrong' would return "that entire string"

If you have a complex expression with multiple values to extract, it is usually clearer to use (?P<groupName>...) named groups rather than unnamed groups referenced by index. This produces a dictionary:

authInfo = self.getExprFromFile('myserver.log', expr=r'Successfully authenticated user "(?P<username>[^"]*)" in (?P<authSecs>[^ ]+) seconds\.'))

allAuthList = self.getExprFromFile('myserver.log', expr=r'Successfully authenticated user "(?P<username>[^"]*)" in (?P<authSecs>[^ ]+) seconds\.', returnAll=True))

See also pysys.basetest.BaseTest.assertThatGrep which should be used when instead of just finding out what’s in the file you want to assert that a specific expression is matched. The documentation for assertGrep also provides some helpful examples of regular expressions that could also be applied to this method, and tips for dealing with escaping in regular expressions.

Changed in version 1.6.0: Support for named groups was added in 1.6.0.

Parameters

• path (str) – file to search (located in the output dir unless an absolute path is specified)

• expr (str) –

  the regular expression, optionally containing the regex group operator (...)

  Remember to escape regular expression special characters such as ., (, [, { and \ if you want them to be treated as literal values. If you have a string with regex backslashes, it’s best to use a ‘raw’ Python string so that you don’t need to double-escape them, e.g. expr=r'function[(]"str", 123[.]4, (\d+), .*[)]'.

• groups (List[int]) – which numeric regex group numbers (as indicated by brackets in the regex) should be returned; default is [1] meaning the first group. If more than one group is specified, the result will be a tuple of group values, otherwise the result will be the value of the group at the specified index as a str. This parameter is ignored if the regular expression contains any (?P<groupName>...) named groups.

• returnAll (bool) – returns a list containing all matching lines if True, the first matching line otherwise.

• returnNoneIfMissing (bool) – True to return None instead of raising an exception if the regex is not found in the file (not needed when returnAll is used).

• mustExist (bool) – Set to False to tolerate the file not existing and treat a missing file like an empty file.

• encoding (str) – The encoding to use to open the file. The default value is None which indicates that the decision will be delegated to the getDefaultFileEncoding() method.

• encodingReplaceOnError (bool) – Set to True to replace erroneous characters that are invalid in the expected encoding (with a backslash escape) rather than throwing an exception. Added in PySys 2.2.

• mappers (List[callable[str]->str]) –

  A list of filter functions that will be used to pre-process each line from the file (returning None if the line is to be filtered out). This provides a very powerful capability for filtering the file, for example pysys.mappers.IncludeLinesBetween provides the ability to filter in/out sections of a file.

  Do not share mapper instances across multiple tests or threads as this can cause race conditions.

  Added in PySys 1.6.0.

• reFlags (int) –

  Zero or more flags controlling how the behaviour of regular expression matching, combined together using the | operator, for example reFlags=re.VERBOSE | re.IGNORECASE.

  For details see the re module in the Python standard library. Note that re.MULTILINE cannot be used because expressions are matched against one line at a time. Added in PySys 1.5.1.

Returns

For a regular expression with one unnamed group, the match value is a str; if there are multiple unnamed numeric groups it is List[str] (with values corresponding to the groups= argument); if it contains any (?P<groupName>...) named groups a dict[str,str] is returned where the keys are the groupNames.

If returnAll=True, the return value is a list of all the match values, with types as above.

getInstanceCount(displayName)

(Deprecated) Return the number of processes started within the testcase matching the supplied displayName.

Deprecated

The recommended way to allocate unique names is now allocateUniqueStdOutErr

The ProcessUser class maintains a reference count of processes started within the class instance via the startProcess() method. The reference count is maintained against a logical name for the process, which is the displayName used in the method call to startProcess(), or the basename of the command if no displayName was supplied. The method returns the number of processes started with the supplied logical name, or 0 if no processes have been started.

Parameters

displayName – The process display name

Returns

The number of processes started matching the command basename

Return type

int

getNextAvailableTCPPort(hosts=['', 'localhost'], socketAddressFamily=AddressFamily.AF_INET)

Allocate a free TCP port which can be used for starting a server on this machine.

The port is taken from the pool of available server (non-ephemeral) ports on this machine, and will not be available for use by any other code in the current PySys process until this object’s cleanup method is called to return it to the pool of available ports. For advanced options such as port exclusions see pysys.utils.allocport.

To allocate an IPv4 port for use only on this host:

port = self.getNextAvailableTCPPort(hosts=['localhost'])

Changed in version 1.5.1: Added hosts and socketAddressFamily parameters.

Parameters

• hosts (list(Str)) –

  A list of the host names or IP addresses to check when establishing that a potential allocated port isn’t already in use by a process outside the PySys framework. By default we check "" (which corresponds to INADDR_ANY and depending on the OS means either one or all non-localhost IPv4 addresses) and also localhost.

  Many machines have multiple network cards each with its own host IP address, and typically you’ll only be using one of them in your test, most commonly localhost. If you do know which host/IP you’ll actually be using, just specify that directly to save time, and avoid needlessly opening remote ports on hosts you’re not using. A list of available host addresses can be found from socket.getaddrinfo('', None).

• socketAddressFamily – The socket address family e.g. IPv4 vs IPv6. See Python’s socket module for details.

getOutcome()

Get the final outcome for this test, based on the precedence order defined in pysys.constants.OUTCOMES.

To find out whether this test has failed:

if self.getOutcome().isFailure():
        ...

Return pysys.constants.Outcome

The overall outcome. Use %s or str() to convert to a display name.

getOutcomeLocation()

Get the location in the Python source file where this outcome was added.

New in version 1.6.0.

Return (str,str)

The absolute filename, and the line number. Returns (None,None) if not known.

getOutcomeReason()

Get the reason string for the current overall outcome (if specified).

Returns

The overall test outcome reason or ‘’ if not specified

Return type

string

grep(path, expr, encoding=None, reFlags=0, mappers=[], **kwargs)

Returns the first occurrence of a regular expression in the specified file, or raises an exception if not found.

See also grepOrNone and grepAll or no-error-on-missing and return-all behaviour.

If you want to use a grep to set the outcome of the test, use pysys.basetest.BaseTest.assertThatGrep or pysys.basetest.BaseTest.assertGrep instead. The documentation for assertGrep also provides some helpful examples of regular expressions that could also be used with this method, and tips for escaping in regular expressions.

If you have a complex expression with multiple values to extract, you can use (?P<groupName>...) named groups in which case a dictionary is returned providing access to the individual elements:

authInfoDict = self.grep('myserver.log', expr=r'Successfully authenticated user "(?P<username>[^"]*)" in (?P<authSecs>[^ ]+) seconds\.'))

For extracting a single value you can use an unnamed group using (expr) syntax, in which case that group is returned:

myKey = self.grep('test.txt', r'myKey="(.*)"') # on a file containing 'myKey="foobar"' would return "foobar"

Parameters

• path (str) – file to search (located in the output dir unless an absolute path is specified)

• expr (str) –

  the regular expression, optionally containing named groups.

  Remember to escape regular expression special characters such as ., (, [, { and \ if you want them to be treated as literal values. If you have a string with regex backslashes, it’s best to use a ‘raw’ Python string so that you don’t need to double-escape them, e.g. expr=r'function[(]"str", 123[.]4, (\d+), .*[)]'.

• encoding (str) – The encoding to use to open the file. The default value is None which indicates that the decision will be delegated to the getDefaultFileEncoding() method.

• mappers (List[callable[str]->str]) –

  A list of filter functions that will be used to pre-process each line from the file (returning None if the line is to be filtered out). This provides a very powerful capability for filtering the file, for example pysys.mappers.IncludeLinesBetween provides the ability to filter in/out sections of a file.

  Do not share mapper instances across multiple tests or threads as this can cause race conditions.

  Added in PySys 1.6.0.

• reFlags (int) –

  Zero or more flags controlling how the behaviour of regular expression matching, combined together using the | operator, for example reFlags=re.VERBOSE | re.IGNORECASE.

  For details see the re module in the Python standard library. Note that re.MULTILINE cannot be used because expressions are matched against one line at a time. Added in PySys 1.5.1.

Returns

A str containing the matching expression, or if the expr contains any (?P<groupName>...) named groups a dict[str,str] is returned where the keys are the groupNames.

grepAll(path, expr, encoding=None, reFlags=0, mappers=[], mustExist=True, **kwargs)

Returns a list of all the occurrences of a regular expression in the specified file.

See also grep and grepOrNone for return-first-only behaviour.

If you have a complex expression with multiple values to extract, you can use (?P<groupName>...) named groups in which case each item in the returned list is a dictionary is returned providing access to the individual elements:

authInfoDictList = self.grepAll('myserver.log', expr=r'Successfully authenticated user "(?P<username>[^"]*)" in (?P<authSecs>[^ ]+) seconds\.'))

For extracting a single value you can use an unnamed group using (expr) syntax, in which case that group is returned:

myKey = self.grepAll('test.txt', r'myKey="(.*)"') # on a file containing 'myKey="foobar"' would return ["foobar"]

Parameters

• path (str) – file to search (located in the output dir unless an absolute path is specified)

• expr (str) –

  the regular expression, optionally containing named groups.

  Remember to escape regular expression special characters such as ., (, [, { and \ if you want them to be treated as literal values. If you have a string with regex backslashes, it’s best to use a ‘raw’ Python string so that you don’t need to double-escape them, e.g. expr=r'function[(]"str", 123[.]4, (\d+), .*[)]'.

• encoding (str) – The encoding to use to open the file. The default value is None which indicates that the decision will be delegated to the getDefaultFileEncoding() method.

• mappers (List[callable[str]->str]) –

  A list of filter functions that will be used to pre-process each line from the file (returning None if the line is to be filtered out). This provides a very powerful capability for filtering the file, for example pysys.mappers.IncludeLinesBetween provides the ability to filter in/out sections of a file.

  Do not share mapper instances across multiple tests or threads as this can cause race conditions.

  Added in PySys 1.6.0.

• mustExist (bool) – Set this to False to tolerate the file not existing and treat a missing file like an empty file. Added in PySys 2.2.

• reFlags (int) –

  Zero or more flags controlling how the behaviour of regular expression matching, combined together using the | operator, for example reFlags=re.VERBOSE | re.IGNORECASE.

  For details see the re module in the Python standard library. Note that re.MULTILINE cannot be used because expressions are matched against one line at a time. Added in PySys 1.5.1.

Returns

A list where each item is a str containing the matching expression, or if the expr contains any (?P<groupName>...) named groups each item is a dict[str,str] where the keys are the groupNames.

grepOrNone(path, expr, encoding=None, reFlags=0, mappers=[], mustExist=True, **kwargs)

Returns the first occurrence of a regular expression in the specified file, or None if not found.

See also grep and grepAll for error-on-missing and return-all behaviour.

If you want to use a grep to set the outcome of the test, use pysys.basetest.BaseTest.assertThatGrep or pysys.basetest.BaseTest.assertGrep instead. The documentation for assertGrep also provides some helpful examples of regular expressions that could also be used with this method, and tips for escaping in regular expressions.

If you have a complex expression with multiple values to extract, you can use (?P<groupName>...) named groups in which case a dictionary is returned providing access to the individual elements:

authInfoDict = self.grepOrNone('myserver.log', 
                expr=r'Successfully authenticated user "(?P<username>[^"]*)" in (?P<authSecs>[^ ]+) seconds\.')
        ) or {'username':'myuser', 'authSecs': '0.0'}

For extracting a single value you can use an unnamed group using (expr) syntax, in which case that group is returned:

myKey = self.grepOrNone('test.txt', r'myKey="(.*)"') or 'mydefault' # on a file containing 'myKey="foobar"' would return "foobar"

Parameters

• path (str) – file to search (located in the output dir unless an absolute path is specified)

• expr (str) –

  the regular expression, optionally containing named groups.

  Remember to escape regular expression special characters such as ., (, [, { and \ if you want them to be treated as literal values. If you have a string with regex backslashes, it’s best to use a ‘raw’ Python string so that you don’t need to double-escape them, e.g. expr=r'function[(]"str", 123[.]4, (\d+), .*[)]'.

• encoding (str) – The encoding to use to open the file. The default value is None which indicates that the decision will be delegated to the getDefaultFileEncoding() method.

• mappers (List[callable[str]->str]) –

  A list of filter functions that will be used to pre-process each line from the file (returning None if the line is to be filtered out). This provides a very powerful capability for filtering the file, for example pysys.mappers.IncludeLinesBetween provides the ability to filter in/out sections of a file.

  Do not share mapper instances across multiple tests or threads as this can cause race conditions.

  Added in PySys 1.6.0.

• mustExist (bool) – Set this to False to tolerate the file not existing and treat a missing file like an empty file. Added in PySys 2.2.

• reFlags (int) –

  Zero or more flags controlling how the behaviour of regular expression matching, combined together using the | operator, for example reFlags=re.VERBOSE | re.IGNORECASE.

  For details see the re module in the Python standard library. Note that re.MULTILINE cannot be used because expressions are matched against one line at a time. Added in PySys 1.5.1.

Returns

A str containing the matching expression, None if there are no matches, or if the expr contains any (?P<groupName>...) named groups a dict[str,str] is returned where the keys are the groupNames.

handleRunnerAbort(**kwargs)

Called from a background thread when the entire test run is aborting, to perform quick operations to help this test to terminate as quickly as possible.

The default implementation attempts to immediately stop any currently running processes (in case they are holding open resources such as server sockets that the test may be blocking on).

Subclasses may override this method, either to perform additional steps (such as closing server sockets that clients may be blocking on) or to avoid stopping processes that need to be terminated in a more orderly way.

Unlike the cleanup method, this will be called from a background thread so avoid using methods that are not thread-safe.

NB: Logging performed during this method will NOT be included in the test’s run.log output.

The test’s cleanup method will usually be called to perform a fuller cleanup (later, or concurrently).

New in version 2.2.

listDirContents(path, recurse=True)

Recursively scans the specified directory and returns a sorted list of the file/directory paths under it suitable for diffing.

The contents are returned in a normalized form suitable for diffing: relative to the scanned path, with forward slashes on all platforms, a trailing slash for directories, and sorted to ensure deterministic results. Symbolic links are not searched.

For example this can be used with pysys.basetest.BaseTest.assertDiff like this:

self.assertDiff(
        self.write_text('MyDir-contents.txt', '\\n'.join( self.listDirContents('MyDir') )))

Parameters

• path (str) – The path to search, either absolute or relative to the output directory.

• recurse (bool) – Set this to False to just include the specified directory but not any children.

Returns

A list of strings with the relative paths found, e.g. ["mysubdir/myfile.txt", "mysubdir/mysubsubdir/"].

New in version 2.2.

logFileContents(path, includes=None, excludes=None, maxLines=20, tail=False, encoding=None, logFunction=None, reFlags=0, stripWhitespace=True, mappers=[], color=True, message=None)

Logs some or all of the lines from the specified file.

If the file does not exist or cannot be opened, does nothing. The method is useful for providing key diagnostic information (e.g. error messages from tools executed by the test) directly in run.log, or to make test failures easier to triage quickly.

Parameters

• path (str) – May be an absolute, or relative to the test output directory.

• includes (list[str]) – Optional list of regex strings. If specified, only matches of these regexes will be logged.

• excludes (list[str]) –

  Optional list of regex strings. If specified, no line containing these will be logged.

  The variable self.logFileContentsDefaultExcludes (= [] by default) is used when this method is called with the default argument of excludes=None, and can be used to provide a global set of default exclusion lines shared by all your tests, which is particularly useful if some processes always log some unimportant text to stderr (or stdout) that would be distracting to log out.

  Added in PySys 1.6.0.

• mappers (List[callable[str]->str]) –

  A list of filter functions that will be used to pre-process each line from the file (returning None if the line is to be filtered out). This provides a very powerful capability for filtering the file, for example pysys.mappers.IncludeLinesBetween provides the ability to filter in/out sections of a file.

  Do not share mapper instances across multiple tests or threads as this can cause race conditions.

  Added in PySys 2.0.

• maxLines (int) – Upper limit on the number of lines from the file that will be logged. Set to zero for unlimited

• tail (bool) – Prints the _last_ ‘maxLines’ in the file rather than the first ‘maxLines’.

• encoding (str) –

  The encoding to use to open the file. The default value is None which indicates that the decision will be delegated to the getDefaultFileEncoding() method.

  Any character encoding errors will result in backslash escape sequences being logged instead.

• logFunction (Callable[[line],None]) –

  The function that will be used to log individual lines from the file. Usually this is self.log.info(u'  %s', line, extra=BaseLogFormatter.tag(LOG_FILE_CONTENTS)) but a custom implementation can be provided, for example to provide a different color using pysys.utils.logutils.BaseLogFormatter.tag.

  Added in PySys 1.5.1.

• reFlags (int) –

  Zero or more flags controlling how the behaviour of regular expression matching, combined together using the | operator, for example reFlags=re.VERBOSE | re.IGNORECASE.

  For details see the re module in the Python standard library. Note that re.MULTILINE cannot be used because expressions are matched against one line at a time. Added in PySys 1.5.1.

• stripWhitespace (bool) – By default blank lines are removed; set this to False to disable that behaviour. Added in PySys 2.0.

• color (bool) – By default logged lines are colored blue to distinguish from the rest of the log contents. Set this to False to disable coloring. Added in PySys 2.1.

• message (str) – The introductory message to log before the file content, with @PATH@ as a placeholder for the path. If not specified the default is equivalent to "Contents of @PATH@: ". Added in PySys 2.2

Returns

True if anything was logged, False if not.

mkdir(path)

Create a directory, with recursive creation of any parent directories.

This function does nothing (does not raise an except) if the directory already exists.

Parameters

path – The path to be created. This can be an absolute path or relative to the testcase output directory.

Returns

the absolute path of the new directory, to facilitate fluent-style method calling.

pollWait(secs)

Sleeps the current thread for the specified number of seconds, between polling/checking for some condition to be met.

Unlike pysys.basetest.BaseTest.wait (which should be used for larger waits inside tests), pollWait does not log anything.

Use this method instead of time.sleep as it provides PySys the chance to abort test execution early when requested, for example as a result of a keyboard interrupt or signal.

Parameters

secs (float) – The time to sleep for, typically a few hundred milliseconds. Do not use this method for really long waits. Cannot be negative.

signalProcess(process, signal, abortOnError=None)

Send a signal to a running process.

This method uses the pysys.process.Process.signal method to send a signal to a running process.

Should the request to send the signal to the running process fail, a BLOCKED outcome will be added to the outcome list.

Parameters

• process – The process handle returned from the startProcess method

• signal – The integer value of the signal to send

• abortOnError – If True aborts the test with an exception on any error, if False just log it as a warning. (defaults to the defaultAbortOnError project setting)

skipTest(outcomeReason, callRecord=None)

Raise an AbortException that will set the test outcome to SKIPPED and ensure that the rest of the execute() and validate() methods do not execute.

This is useful when a test should not be executed in the current mode or platform.

Parameters

outcomeReason – A string summarizing the reason the test is being skipped, for example “Feature X is not supported on Windows”.

startProcess(command, arguments, environs=None, workingDir=None, state=None, timeout=600, stdout=None, stderr=None, displayName=None, abortOnError=None, expectedExitStatus='==0', ignoreExitStatus=None, onError=None, quiet=False, stdouterr=None, background=False, info={}, processFactory=None)

Start a process running in the foreground or background, and return the pysys.process.Process object.

Typical use is:

myexecutable = self.startProcess('path_to_my_executable', 
        arguments=['myoperation', 'arg1','arg2'],
        environs=self.createEnvirons(addToLibPath=['my_ld_lib_path']), # if a customized environment is needed
        stdouterr=self.allocateUniqueStdOutErr('myoperation'), # for stdout/err files, pick a suitable logical name for what it's doing
        background=True # or remove for default behaviour of executing in foreground
        )

The method allows spawning of new processes in a platform independent way. The command, arguments, environment and working directory to run the process in can all be specified in the arguments to the method, along with the filenames used for capturing the stdout and stderr of the process. Processes may be started in the foreground, in which case the method does not return until the process has completed or a time out occurs, or in the background in which case the method returns immediately to the caller returning a handle to the process to allow manipulation at a later stage, typically with waitProcess.

All processes started in the background are automatically killed on completion of the test via the cleanup() destructor. To wait for background processes to complete during execute and/or before verify commences, call waitForBackgroundProcesses(). This is especially useful when you have a test that needs to execute lots of processes asynchronously, since having them all execute concurrently in the background and then calling waitForBackgroundProcesses() will be a lot quicker than executing them serially in the foreground.

When starting a process that will listen on a server socket, use getNextAvailableTCPPort to allocate a free port before calling this method.

Note that although is is possible to use this command to execute OS shell commands, that should only used for testing of shell scripts - other logic such as file system operations can be executed more easily and robustly using built-in Python (os module) or PySys (e.g. BaseTest.copy) functions.

Changed in version 1.6.0: Added onError parameter and default behaviour of logging stderr/out when there’s a failure. Added info parameter.

Changed in version 2.0: Added processFactory parameter.

Parameters

• command (str) – The path to the executable to be launched (should include the full path)

• arguments (list[str]) – A list of arguments to pass to the command. Any non-string values in the list are converted to strings automatically.

• environs (dict(str,str)) – A dictionary specifying the environment to run the process in. If a None or empty dictionary is passed, getDefaultEnvirons will be invoked to produce a suitable clean default environment for this command, containing a minimal set of variables. If you wish to specify a customized environment, createEnvirons() is a great way to create it.

• workingDir (str) – The working directory for the process to run in (defaults to the testcase output subdirectory)

• background (bool) – Set to True to start the process in the background. By default processes are started in the foreground, meaning execution of the test will continue only once the process has terminated.

• state – Alternative way to set background=True. Run the process either in the FOREGROUND or BACKGROUND (defaults to FOREGROUND). Setting state=BACKGROUND is equivalent to setting background=True; in new tests using background=True is the preferred way to do this.

• timeout (int) – The number of seconds after which to terminate processes running in the foreground. For processes that complete in a few seconds or less, it is best to avoid overriding this and stick with the default. However for long-running foreground processes it will be necessary to set a larger number, for example if running a soak test where the process needs to run for up to 2 hours you could set timeout=2*60*60.

• stdouterr (str) – The filename prefix to use for the stdout and stderr of the process (out/err will be appended), or a tuple of (stdout,stderr) as returned from allocateUniqueStdOutErr. The stdouterr prefix is also used to form a default display name for the process if none is explicitly provided. The files are created relative to the test output directory. The filenames can be accessed from the returned process object using .stdout/err from pysys.process.Process.

• stdout (str) – The filename used to capture the stdout of the process. It is usually simpler to use stdouterr instead of this.

• stderr (str) – The filename used to capture the stderr of the process. It is usually simpler to use stdouterr instead of this.

• displayName (str) – Logical name of the process used for display in log messages, and the str(…) representation of the returned process object (defaults to a string generated from the stdouterr and/or the command).

• abortOnError (bool) – If true abort the test on any error outcome (defaults to the defaultAbortOnError project setting)

• expectedExitStatus (str) – The condition string used to determine whether the exit status/code returned by the process is correct. The default is ‘==0’, as an exit code of zero usually indicates success, but if you are expecting a non-zero exit status (for example because you are testing correct handling of a failure condition) this could be set to ‘!=0’ or a specific value such as ‘==5’.

• ignoreExitStatus (bool) –

  If False, a BLOCKED outcome is added if the process terminates with an exit code that doesn’t match expectedExitStatus (or if the command cannot be run at all). This can be set to True in cases where you do not care whether the command succeeds or fails, or wish to handle the exit status separately with more complicated logic.

  The default value of ignoreExitStatus=None means the value will be taken from the project property defaultIgnoreExitStatus, which can be configured in the project XML (the recommended default property value is defaultIgnoreExitStatus=False), or is set to True for compatibility with older PySys releases if no project property is set.

• onError (Callable[pysys.process.Process]->str) –

  A function that will be called if the process times out or returns an unexpected exit status (unless ignoreExitStatus=True), before any abort exception is raised. This provides a convenient place to add logging of diagnostic information (perhaps using the stdout/err of the process) and/or extracting and returning an error message from the output, for example: onError=lambda process: self.logFileContents(process.stderr, tail=True) or self.logFileContents(process.stdout, tail=True).

  If a string value is returned from it will be added to the failure reason, e.g. onError=lambda process: self.logFileContents(process.stderr, tail=True) and self.grepOrNone(process.stderr, 'Error: (.*)').

  If no onError function is specified, the default is to log the last few lines of stderr (or if empty, stdout) when a process fails and abortOnError=True.

  The self.logFileContentsDefaultExcludes variable can be used to add regular expressions to exclude unimportant lines of output such as standard startup lines (see logFileContents).

• quiet (bool) – If True, this method will not do any INFO or WARN level logging (only DEBUG level), unless a failure outcome is appended. This parameter can be useful to avoid filling up the log where it is necessary to repeatedly execute a command check for completion of some operation until it succeeds; in such cases you should usually set ignoreExitStatus=True as well since both success and failure exit statuses are valid.

• info (dict[str,obj]) – A dictionary of user-defined information about this process that will be set as a field on the returned Process instance. This is useful for keeping track of things like server port numbers and log file paths.

• processFactory (callable[kwargs]) –

  A callable (such as a class constructor) that returns an instance or subclass of pysys.process.helper.ProcessImpl. This can be used either to provide a custom process subclass with extra features, or to make modifications to the arguments or environment that were specified by the code that invoked startProcess().

  The signature must consist of a **kwargs parameter, the members of which will be populated by the parameters listed in the constructor of pysys.process.Process, and can be modified by the factory. For example:

  def myProcessFactory(**kwargs):
          kwargs['arguments'] = kwargs['arguments'][0]+['my_extra_arg']+kwargs['arguments'][1:]
          return pysys.process.helper.ProcessImpl(**kwargs)
  

Returns

The process object.

Return type

pysys.process.Process

startPython(arguments, disableCoverage=False, **kwargs)

Start a Python process with the specified arguments.

Uses the same Python process the tests are running under.

If PySys was run with the argument -XcodeCoverage or -XpythonCoverage then startPython will add the necessary arguments to enable generation of code coverage. Note that this required the coverage.py library to be installed. If a project property called pythonCoverageArgs exists then its value will be added as (space-delimited) arguments to the coverage tool.

Parameters

• arguments – The arguments to pass to the Python executable. Typically the first one be either the name of a Python script to execute, or -m followed by a module name.

• kwargs – See startProcess for detail on available arguments.

• disableCoverage – Disables code coverage for this specific process. Coverage can also be disabled by setting self.disableCoverage==True on this test instance.

Returns

The process handle of the process.

Return type

pysys.process.Process

stopProcess(process, abortOnError=None)

Stops the specified process, if it is currently running.

Does nothing if the process is not running.

This is equivalent to calling pysys.process.Process.stop(), except it also logs an info message when the process is stopped.

Parameters

• process – The process handle returned from the startProcess method

• abortOnError – If True abort the test on any error outcome (defaults to the defaultAbortOnError project setting), if False a failure to stop the process will just be logged as a warning.

unpackArchive(archive, dest=None, autoCleanup=True)

Unpacks the specified file(s) from an archive to a directory. Supports archive format such as zip/tar.gz/gz/tar.xz/xz.

It is a good idea to store large textual Input/ assets (such as log files, which usually compress very well) as compressed archives to reduce disk space in your version control system.

By default this method will automatically delete the extracted file/dir during test cleanup so it doesn’t sit around on disk (or in CI uploaded failure archives) consuming space; if the file/dir is mutated by the test you may wish to disable this so you can manually inspect them by setting autoCleanup=False.

For example:

unpacked = self.unpackArchive('mybigfile.log.xz')
# do something with "unpacked"...

Note that .xz (for single files) and .tar.xz (for multiple files) are recommended for optimal compression, and these (and .gz) are significantly better than zip, which performs poorly when compressing multiple similar text files into one archive. Don’t use more than one single archive per testcase (if possible) to ensure you benefit from similarities between the various files.

Files are decompressed in binary mode, so if you require platform-native line endings you should use copy to post-process them after decompressing.

Parameters

• archive (str) – The path of the archive to unpack, by default from the test input directory. Alternatively you could provide an absolute path using self.project.testRootDir or similar if an archive is shared across multiple test cases.

• dest (str) – The directory in which the contents of the archive will be written; by default this is the test output directory for archive types that are always single-file, and a subdirectory named after the archive if not. This dir will be created if needed.

• autoCleanup (bool) – Automatically deletes the unpackaged file/directory during test cleanup to save disk space (even if the test fails).

Returns

The full path to the decompressed file or directory.

waitForBackgroundProcesses(includes=[], excludes=[], timeout=600, abortOnError=None, checkExitStatus=True)

Wait for any running background processes to terminate, then check that all background processes completed with the expected exit status.

This can be useful for speeding up a test that needs to run many processes, by executing all its subprocesses in parallel in the background (and then waiting for completion) rather than one-by-one in the foreground.

Timeouts will result in a TIMEDOUT outcome and an exception unless the project property defaultAbortOnError==False is set.

Parameters

• includes (list[pysys.process.Process]) – A list of processes to wait for, each returned by startProcess(). If none are specified, this method will wait for (and check the exit status of) all background processes.

• excludes (list[pysys.process.Process]) – A list of processes which are not expected to have terminated yet (this is only useful when not setting includes=[]).

• timeout (int) – The total time in seconds to wait for all processes to have completed, for example timeout=TIMEOUTS['WaitForProcess'].

• abortOnError (bool) – If True aborts the test with an exception on any error, if False appends an outcome but does not raise an exception.

• checkExitStatus (bool) – By default this method not only waits for completion but also checks the exit status of all (included) background processes (regardless of when they completed), but set this argument to False to disable checking that the exit status of the processes matches the expectedExitStatus specified in the call to startProcess (typically ==0). The last few lines of the stderr (or stdout) will be logged if the exit status is wrong.

waitForFile(file, filedir=None, timeout=30, abortOnError=None)

Wait for a file to exist on disk.

This method blocks until a file is created on disk. This is useful for test timing where a component under test creates a file (e.g. for logging) indicating it has performed all initialisation actions and is ready for the test execution steps. If a file is not created on disk within the specified timeout interval, the method returns to the caller.

Parameters

• file – The basename of the file used to wait to be created

• filedir – The dirname of the file (defaults to the testcase output subdirectory)

• timeout – The timeout in seconds to wait for the file to be created

• abortOnError – If true abort the test on any failure (defaults to the defaultAbortOnError project setting)

waitForGrep(file, expr='', condition='>=1', timeout=60, poll=0.25, ignores=[], process=None, errorExpr=[], errorIf=None, abortOnError=None, encoding=None, encodingReplaceOnError=False, detailMessage='', filedir=None, reFlags=0, mappers=[], quiet=False)

Wait for a regular expression line to be seen (one or more times) in a text file in the output directory (waitForGrep was formerly known as waitForSignal).

This method provides some parameters that give helpful fail-fast behaviour with a descriptive outcome reason; use these whenever possible:

• process= to abort if success becomes impossible due to premature termination of the process that’s generating the output

• errorExpr= to abort if an error message/expression is written to the file being grepped

• errorIf= to abort if the specified lambda function returns an error string (which can be used if the error messages go to a different file than that being grepped

This will generate much clearer outcome reasons, which makes test failures easy to triage, and also avoids wasting time waiting for something that will never happen.

Example:

self.waitForGrep('myprocess.log', 'INFO .*Started successfully', encoding='utf-8',
        process=myprocess, errorExpr=[' (ERROR|FATAL) ', 'Failed to start'])

self.waitForGrep('myoutput.log', 'My message', encoding='utf-8',
        process=myprocess, errorIf=lambda: self.grepOrNone('myprocess.err', ' ERROR .*'))

Note that waitForGrep fails the test if the expression is not found (unless abortOnError was set to False, which isn’t recommended), so there is no need to add duplication with an assertGrep to check for the same expression in your validation logic.

You can extract information from the matched expression, optionally perform assertions on it, by using one or more (?P<groupName>...) named groups in the expression. A common pattern is to unpack the resulting dict using **kwargs syntax and pass to BaseTest.assertThat. For example:

self.assertThat('username == expected', expected='myuser',
        **self.waitForGrep('myserver.log', r'Successfully authenticated user "(?P<username>[^"]*)"'))

If the file is large or contains long lines, it can take a long time for the regular expressions to be evaluated over each line. It is important to avoid the possibility that data is written to the file faster than Python can read it, which would lead to the PySys process running very slowly and likely a timeout. To help detect this situation, this method will log warnings if dangerously long lines are detected. If needed the threshold for these can be configured by setting the self.grepWarnIfLineLongerThan field. If reading from a file that has long lines, consider adding pysys.mappers.TruncateLongLines to the mappers list.

New in version 1.5.1.

Parameters

• file (str) – The path of the file to be searched. Usually this is a name/path relative to the self.output directory, but alternatively an absolute path can be specified.

• expr (str) – The regular expression to search for in the text file.

• condition (str) – The condition to be met for the number of lines matching the regular expression; by default we wait until there is at least one occurrence.

• timeout (int) – The number of seconds to wait for the regular expression before giving up and aborting the test with pysys.constants.TIMEDOUT (unless abortOnError=False in which case execution will continue).

• process (pysys.process.Process) – The process that is generating the specified file, to allow the wait to fail fast (instead of timing out) if the process dies before the expected signal appears. Can be None if the process is not known or is expected to terminate itself during this period.

• errorExpr (list[str]) – Optional list of regular expressions, which if found in the file will cause waiting for the main expression to be aborted with a pysys.constants.BLOCKED outcome. This is useful to avoid waiting a long time for the expected expression when an ERROR is logged that means it will never happen, and also provides much clearer test failure messages in this case.

• errorIf (callable->str) –

  A zero-arg function that returns False/None when there is no error, or a non-empty string if an error is detected which should cause us to abort looking for the grep expression. This function will be executed frequently (every poll seconds) so avoid doing anything time-consuming here unless you set a large polling interval. See above for an example.

  Added in PySys 1.6.0.

• ignores (list[str]) – A list of regular expressions used to identify lines in the files which should be ignored when matching both expr and errorExpr.

• mappers (List[callable[str]->str]) –

  A list of filter functions that will be used to pre-process each line from the file (returning None if the line is to be filtered out). This provides a very powerful capability for filtering the file, for example pysys.mappers.IncludeLinesBetween provides the ability to filter in/out sections of a file, and pysys.mappers.JoinLines can be used to put exception stack traces onto the same line as the error message.

  Do not share mapper instances across multiple tests or threads as this can cause race conditions.

  Added in PySys 1.6.0.

• poll (float) – The time in seconds between to poll the file looking for the regular expression and to check against the condition

• abortOnError (bool) – If True abort the test on any error outcome (defaults to the defaultAbortOnError project setting, which for a modern project will be True).

• encoding (str) – The encoding to use to open the file and convert from bytes to characters. The default value is None which indicates that the decision will be delegated to the getDefaultFileEncoding() method.

• encodingReplaceOnError (bool) – Set to True to replace erroneous characters that are invalid in the expected encoding (with a backslash escape) rather than throwing an exception. Added in PySys 2.2.

• detailMessage (str) –

  An extra string to add to the start of the message logged when waiting to provide extra information about the wait condition. e.g. detailMessage='Wait for server startup: '.

  Added in v1.5.1. From v2.1+ the detail string is added at the beginning not the end.

• reFlags (int) –

  Zero or more flags controlling how the behaviour of regular expression matching, combined together using the | operator, for example reFlags=re.VERBOSE | re.IGNORECASE.

  For details see the re module in the Python standard library. Note that re.MULTILINE cannot be used because expressions are matched against one line at a time. Added in PySys 1.5.1.

• filedir (str) – Can be used to provide a directory name to add to the beginning of the file parameter; however usually it is clearer just to specify that directory in the file.

• quiet (bool) – Set this to true to suppress INFO-level logging, which can be useful when you wish to print your own progress message in a more high-level fashion.

Return list[re.Match]

Usually this returns a list of re.Match objects found for the expr, or an empty list if there was no match.

If the expr contains any (?P<groupName>...) named groups, and assuming the condition is still the default of “>=1” (i.e. not trying to find multiple matches), then instead of a list, a dict is returned containing dict(groupName: str, matchValue: str or None) (or an empty {} dict if there is no match) which allows the result to be passed to assertThat for further checking of the matched groups (typically unpacked using the ** operator; see example above).

waitForSignal(file, filedir=None, expr='', **waitForGrepArgs)

Old alias for waitForGrep; please use waitForGrep in new tests.

All parameters are the same, except that in waitForSignal the (rarely used) filedir argument can be specified as the 2nd positional argument (after file and before expr) whereas in waitForGrep it can only be specified as a filedir= keyword argument.

waitForSocket(port, host='localhost', timeout=60, abortOnError=None, process=None, socketAddressFamily=AddressFamily.AF_INET)

Wait until it is possible to establish a socket connection to a server running on the specified local or remote port.

This method blocks until connection to a particular host:port pair can be established. This is useful for test timing where a component under test creates a socket for client server interaction - calling of this method ensures that on return of the method call the server process is running and a client is able to create connections to it. If a connection cannot be made within the specified timeout interval, the method returns to the caller, or aborts the test if abortOnError=True.

Changed in version 1.5.1: Added host and socketAddressFamily parameters.

Parameters

• port – The port value in the socket host:port pair

• host – The host value in the socket host:port pair

• timeout – The timeout in seconds to wait for connection to the socket

• abortOnError – If true abort the test on any failure (defaults to the defaultAbortOnError project setting)

• process – If a handle to a process is specified, the wait will abort if the process dies before the socket becomes available. It is recommended to set this wherever possible.

• socketAddressFamily – The socket address family e.g. IPv4 vs IPv6. See Python’s socket module for details.

waitProcess(process, timeout=600, abortOnError=None, checkExitStatus=False)

Wait for a background process to terminate.

For a convenient way to wait for all remaining background processes to complete, see waitForBackgroundProcesses.

Timeouts will result in an exception and TIMEDOUT outcome unless the project property defaultAbortOnError==False is set.

Parameters

• process (pysys.process.Process) – The process handle returned from the startProcess method

• timeout (int) – The timeout value in seconds to wait before returning, for example timeout=TIMEOUTS['WaitForProcess'].

• abortOnError (bool) – If True aborts the test with an exception on any error, if False just log it as a warning. (defaults to the defaultAbortOnError project setting)

• checkExitStatus (bool) – By default this method does not check the exit status, but set this argument to True to check that the exit status matches the expectedExitStatus specified in the call to startProcess (typically ==0). Note that this argument is not affected by the defaultIgnoreExitStatus project property. The last few lines of the stderr (or stdout) will be logged if the exit status is wrong.

Returns

The process’s exitStatus. This will be None if the process timed out and abortOnError is disabled.

writeProcess(process, data, addNewLine=True)

Write binary data to the stdin of a process.

This method uses pysys.process.Process.write to write binary data to the stdin of a process. This wrapper around the write method of the process helper only adds checking of the process running status prior to the write being performed, and logging to the testcase run log to detail the write.

Parameters

• process (pysys.process.Process) – The process handle returned from the startProcess() method

• data (bytes) – The data to write to the process stdin. As only binary data can be written to a process stdin, if a character string rather than a byte object is passed as the data, it will be automatically converted to a bytes object using the encoding given by PREFERRED_ENCODING.

• addNewLine (bool) – True if a new line character is to be added to the end of the data string

write_text(file, text, encoding=None)

Writes the specified characters to a file in the output directory.

Parameters

• file – The path of the file to write, either an absolute path or relative to the self.output directory.

• text –

  The string to write to the file, with \n for newlines (do not use os.linesep as the file will be opened in text mode so platform line separators will be added automatically).

  This must be a character string.

• encoding – The encoding to use to open the file. The default value is None which indicates that the decision will be delegated to the getDefaultFileEncoding() method.

Return str

Return the absolute path of the generated file.

log

The logger instance that should be used to log from this class.

project

The pysys.config.project.Project instance containing settings for this PySys project.

lock

A recursive lock that can be used for protecting the fields of this instance from access by background threads, as needed.

Do NOT hold this lock while performing long operations or acquiring other locks.

grepTruncateIfLineLongerThan

Set this to a number of characters to automatically truncate long lines during waitForGrep (after all mappers have completed) to the specified length. This prevents warnings or slow regular expression in large/long log files.

New in version 2.2.

pythonDocTest(pythonFile, pythonPath=None, output=None, environs=None, **kwargs)

Execute the Python doctests that exist in the specified python file; adds a FAILED outcome if any do not pass.

Parameters

• pythonFile – the absolute path to a python file name.

• pythonPath – a list of directories to be added to the PYTHONPATH.

• output – the output file; if not specified, ‘%s-doctest.txt’ is used with the basename of the python file.

• kwargs – extra arguments are passed to startProcess/startPython.