bpo-45046: Support context managers in unittest (GH-28045)

Add methods enterContext() and enterClassContext() in TestCase.
Add method enterAsyncContext() in IsolatedAsyncioTestCase.
Add function enterModuleContext().

2 files changed, 54 insertions, 0 deletions

diff --git a/Doc/library/unittest.rst b/Doc/library/unittest.rst
index 9b8b75a..f6bcba0 100644
--- a/Doc/library/unittest.rst
+++ b/Doc/library/unittest.rst
@@ -1495,6 +1495,16 @@ Test cases
       .. versionadded:: 3.1
 
 
+   .. method:: enterContext(cm)
+
+      Enter the supplied :term:`context manager`.  If successful, also
+      add its :meth:`~object.__exit__` method as a cleanup function by
+      :meth:`addCleanup` and return the result of the
+      :meth:`~object.__enter__` method.
+
+      .. versionadded:: 3.11
+
+
    .. method:: doCleanups()
 
       This method is called unconditionally after :meth:`tearDown`, or
@@ -1510,6 +1520,7 @@ Test cases
 
       .. versionadded:: 3.1
 
+
    .. classmethod:: addClassCleanup(function, /, *args, **kwargs)
 
       Add a function to be called after :meth:`tearDownClass` to cleanup
@@ -1524,6 +1535,16 @@ Test cases
       .. versionadded:: 3.8
 
 
+   .. classmethod:: enterClassContext(cm)
+
+      Enter the supplied :term:`context manager`.  If successful, also
+      add its :meth:`~object.__exit__` method as a cleanup function by
+      :meth:`addClassCleanup` and return the result of the
+      :meth:`~object.__enter__` method.
+
+      .. versionadded:: 3.11
+
+
    .. classmethod:: doClassCleanups()
 
       This method is called unconditionally after :meth:`tearDownClass`, or
@@ -1571,6 +1592,16 @@ Test cases
 
       This method accepts a coroutine that can be used as a cleanup function.
 
+   .. coroutinemethod:: enterAsyncContext(cm)
+
+      Enter the supplied :term:`asynchronous context manager`.  If successful,
+      also add its :meth:`~object.__aexit__` method as a cleanup function by
+      :meth:`addAsyncCleanup` and return the result of the
+      :meth:`~object.__aenter__` method.
+
+      .. versionadded:: 3.11
+
+
    .. method:: run(result=None)
 
       Sets up a new event loop to run the test, collecting the result into
@@ -2465,6 +2496,16 @@ To add cleanup code that must be run even in the case of an exception, use
    .. versionadded:: 3.8
 
 
+.. classmethod:: enterModuleContext(cm)
+
+   Enter the supplied :term:`context manager`.  If successful, also
+   add its :meth:`~object.__exit__` method as a cleanup function by
+   :func:`addModuleCleanup` and return the result of the
+   :meth:`~object.__enter__` method.
+
+   .. versionadded:: 3.11
+
+
 .. function:: doModuleCleanups()
 
    This function is called unconditionally after :func:`tearDownModule`, or
@@ -2480,6 +2521,7 @@ To add cleanup code that must be run even in the case of an exception, use
 
    .. versionadded:: 3.8
 
+
 Signal Handling
 ---------------
 
diff --git a/Doc/whatsnew/3.11.rst b/Doc/whatsnew/3.11.rst
index c4e8e6f..defaeeb 100644
--- a/Doc/whatsnew/3.11.rst
+++ b/Doc/whatsnew/3.11.rst
@@ -758,6 +758,18 @@ unicodedata
 * The Unicode database has been updated to version 14.0.0. (:issue:`45190`).
 
 
+unittest
+--------
+
+* Added methods :meth:`~unittest.TestCase.enterContext` and
+  :meth:`~unittest.TestCase.enterClassContext` of class
+  :class:`~unittest.TestCase`, method
+  :meth:`~unittest.IsolatedAsyncioTestCase.enterAsyncContext` of
+  class :class:`~unittest.IsolatedAsyncioTestCase` and function
+  :func:`unittest.enterModuleContext`.
+  (Contributed by Serhiy Storchaka in :issue:`45046`.)
+
+
 venv
 ----