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authorBrett Cannon <bcannon@gmail.com>2003-05-07 22:02:17 (GMT)
committerBrett Cannon <bcannon@gmail.com>2003-05-07 22:02:17 (GMT)
commit066f3928b2b8f4bfc01cce66d339407e23ac02a1 (patch)
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Library documentation for the 'test' package. Still needs to be checked by Fred.
Diffstat (limited to 'Doc')
-rw-r--r--Doc/lib/lib.tex1
-rw-r--r--Doc/lib/libtest.tex275
2 files changed, 276 insertions, 0 deletions
diff --git a/Doc/lib/lib.tex b/Doc/lib/lib.tex
index 3843d46..928371c 100644
--- a/Doc/lib/lib.tex
+++ b/Doc/lib/lib.tex
@@ -118,6 +118,7 @@ and how to embed it in other applications.
\input{libpydoc}
\input{libdoctest}
\input{libunittest}
+\input{libtest}
\input{libmath}
\input{libcmath}
\input{librandom}
diff --git a/Doc/lib/libtest.tex b/Doc/lib/libtest.tex
new file mode 100644
index 0000000..c295cf4
--- /dev/null
+++ b/Doc/lib/libtest.tex
@@ -0,0 +1,275 @@
+\section{\module{test} ---
+ Regression tests package for Python}
+
+\declaremodule{standard}{test}
+
+\sectionauthor{Brett Cannon}{brett@python.org}
+
+
+\modulesynopsis{Regression tests package containing the testing suite for
+Python.}
+
+
+The \module{test} package contains all regression tests for Python as well as
+the modules \module{test_support} and \module{regrtest.py}.
+\module{test_support} is used to enhance your tests while \module{regrtest.py}
+drives the testing suite.
+
+Each module in the \module{test} package whose name starts with
+\code{'test_'} is a testing suite for a specific module or feature.
+All new tests should be written using the \module{unittest} module; using
+\module{unittest} is not required but makes the tests more flexible and
+maintenance of the tests easier.
+Some older tests are written to use \module{doctest} and a ``traditional''
+testing style; these styles of tests will not be covered.
+
+\begin{seealso}
+\seemodule{unittest}{Writing PyUnit regression tests.}
+\seemodule{doctest}{Tests embedded in documentation strings.}
+\end{seealso}
+
+
+\subsection{test_support \label{test_support-docs}}
+
+The \module{test_support} module contains functions for assisting with writing
+regression tests.
+
+
+The \module{test_support} module defines the following exceptions:
+
+\begin{excdesc}{TestFailed}
+Exception to be raised when a test fails.
+\end{excdesc}
+
+\begin{excdesc}{TestSkipped}
+Subclass of \exception{TestFailed}.
+Raised when a test is skipped.
+This occurs when a needed resource (such as a network connection) is not
+available at the time of testing.
+\end{excdesc}
+
+\begin{excdesc}{ResourceDenied}
+Subclass of \exception{TestSkipped}.
+Raised when a resource (such as a network connection) is not available.
+Raised by the \function{requires} function.
+\end{excdesc}
+
+
+The \module{test_support} module defines the following constants:
+
+\begin{datadesc}{verbose}
+\constant{True} when verbose output is enabled.
+Should be checked when more detailed information is desired about a running
+test.
+\var{verbose} is set by \module{regrtest.py}.
+\end{datadesc}
+
+\begin{datadesc}{have_unicode}
+\constant{True} when Unicode support is available.
+\end{datadesc}
+
+\begin{datadesc}{is_jython}
+\constant{True} if the running interpreter is Jython.
+\end{datadesc}
+
+\begin{datadesc}{TESTFN}
+Set to the path that a temporary file may be created at.
+Any temporary that is created should be closed and unlinked (removed).
+\end{datadesc}
+
+
+The \module{test_support} module defines the following functions:
+
+\begin{funcdesc}{forget}{module_name}
+Removes the module named \var{module_name} from \module{sys.modules} and deletes
+any byte-compiled files of the module.
+\end{funcdesc}
+
+\begin{funcdesc}{is_resource_enabled}{resource}
+Returns \constant{True} if \var{resource} is enabled and available.
+The list of available resources is only set when \module{regrtest.py} is
+executing the tests.
+\end{funcdest}
+
+\begin{funcdesc}{requires}{resource\optional{, msg}}
+Raises \exception{ResourceDenied} if \var{resource} is not available.
+\var{msg} is the argument to \exception{ResourceDenied} if it is raised.
+Always returns true if called by a function whose \var{__name__} is
+\code{"__main__"}.
+Used when tests are executed by \module{regrtest.py}.
+\end{funcdesc}
+
+\begin{funcdesc}{findfile}{filename}
+Return the path to the file named \var{filename}.
+If no match is found \var{filename} is returned.
+This does not equal a failure since it could be the path to the file.
+\end{funcdesc}
+
+\begin{funcdesc}{run_unittest}{*classes}
+Execute \class{unittest.TestCase} subclasses passed to the function.
+The function scans the classes for methods starting with the name
+\code{"test_"} and executes the tests individually.
+This is the preferred way to execute tests.
+\end{datadesc}
+
+\begin{funcdesc}{run_suite}{suite\optional{, testclass=None}}
+Execute the \class{unittest.TestSuite} instance, \var{suite}.
+The optional argument \var{testclass} accepts one of the test classes in the
+suite so as to print out more detailed information on where the testing suite
+originated from.
+\end{funcdesc}
+
+
+
+\subsection{Writing Unit Tests for the \module{test} package \label{writing-tests}}
+
+It is preferred that tests for the \module{test} package use the
+\module{unittest} module and follow a few guidelines.
+One is to have the name of all the test methods start with \code{"test_"} as
+well as the module's name.
+This is needed so that the methods are recognized by the test driver as
+test methods.
+Also, no documentation string for the method should be included.
+A comment (such as
+\var{# Tests function returns only True or False}) should be used to provide
+documentation for test methods.
+This is done because documentation strings get printed out if they exist and
+thus what test is being run is not stated.
+
+A basic boilerplate is often used:
+
+\begin{verbatim}
+import unittest
+from test import test_support
+
+class MyTestCase1(unittest.TestCase):
+
+ # Only use setUp() and tearDown() if necessary
+
+ def setUp(self):
+ ... code to execute in preparation for tests ...
+
+ def tearDown(self):
+ ... code to execute to clean up after tests ...
+
+ def test_feature_one(self):
+ # Test feature one.
+ ... testing code ...
+
+ def test_feature_two(self):
+ # Test feature two.
+ ... testing code ...
+
+ ... more test methods ...
+
+class MyTestCase2(unittest.TestCase):
+ ... same structure as MyTestCase1 ...
+
+... more test classes ...
+
+def test_main():
+ test_support.run_unittest(MyTestCase1,
+ MyTestCase2,
+ ... list other tests ...
+ )
+
+if __name__ == '__main__':
+ test_main()
+\end{verbatim}
+
+This boilerplate code allows the testing suite to be run by \module{regrtest.py}
+as well as on its own as a script.
+
+The goal for regression testing is to try to break code.
+This leads to a few guidelines to be followed:
+
+\begin{itemize}
+\item The testing suite should exercise all classes, functions, and
+ constants.
+ This includes not just the external API that is to be presented to the
+ outside world but also "private" code.
+\item Whitebox testing (examining the code being tested when the tests are
+ being written) is preferred.
+ Blackbox testing (testing only the published user interface) is not
+ complete enough to make sure all boundary and edge cases are tested.
+\item Make sure all possible values are tested including invalid ones.
+ This makes sure that not only all valid values are acceptable but also
+ that improper values are handled correctly.
+\item Exhaust as many code paths as possible.
+ Test where branching occurs and thus tailor input to make sure as many
+ different paths through the code are taken.
+\item Add an explicit test for any bugs discovered for the tested code.
+ This will make sure that the error does not crop up again if the code is
+ changed in the future.
+\item Make sure to clean up after your tests (such as close and remove all
+ temporary files).
+\item Import as few modules as possible and do it as soon as possible.
+ This minimizes external dependencies of tests and also minimizes possible
+ anomalous behavior from side-effects of importing a module.
+\item Try to maximize code reuse.
+ On occasion tests will vary by something as small as what type of input
+ they take.
+ Minimize code duplication by subclassing a basic test class with a class
+ that specifies the input:
+\begin{verbatim}
+class TestFuncAcceptsSequences(unittest.TestCase):
+
+ func = mySuperWhammyFunction
+
+ def test_func(self):
+ self.func(self.arg)
+
+class AcceptLists(TestFuncAcceptsSequences):
+ arg = [1,2,3]
+
+class AcceptStrings(TestFuncAcceptsSequences):
+ arg = 'abc'
+
+class AcceptTuples(TestFuncAcceptsSequences):
+ arg = (1,2,3)
+\end{verbatim}
+\end{itemize}
+
+\begin{seealso}
+\seetitle{Test Driven Development}{A book by Kent Beck on writing tests before
+code}
+\end{seealso}
+
+
+
+\subsection{Running tests Using \module{regrtest.py} \label{regrtest}}
+
+\module{regrtest.py} is the script used to drive Python's regression test
+suite.
+Running the script by itself automatically starts running all
+regression tests in the \module{test} package.
+It does this by finding all modules in the package whose name starts with
+\code{test_}, importing them, and executing the function \function{test_main}
+if present.
+The names of tests to execute may also be passed to the script.
+Specifying a single regression test (\code{python regrtest.py test_spam.py})
+will minimize output and only print whether the test passed or failed and thus
+minimize output.
+
+Running \module{regrtest.py} directly allows what resources are
+available for tests to use to be set.
+You do this by using the \code{-u} command-line option.
+Run \code{python regrtest.py -uall} to turn on all resources;
+specifying \code{all} as an option for \code{-u} enables all possible
+resources.
+If all but one resource is desired (a more common case), a
+comma-separated list of resources that are not desired may be listed after
+\code{all}.
+The command \code{python regrtest.py -uall,-audio,-largefile} will run
+\module{regrtest.py} with all resources except the audio and largefile
+resources.
+For a list of all resources and more command-line options, run
+\code{python regrtest.py -h}.
+
+Some other ways to execute the regression tests depend on what platform the
+tests are being executed on.
+On \UNIX{}, you can run \code{make test} at the top-level directory
+where Python was built.
+On Windows, executing \code{rt.bat} from your PCBuild directory will run all
+regression tests.
+