whatsnew: unittest discover works on namespace packages (#17457).

I also added the docs that never got committed, editing the patch provided by
Claudiu.

I collapsed the now three versionchanged directives for discovery into one.  I
tried several different styles for this.  The most obvious is a bulleted list,
but currently the only way I could find to produce that is to have *something*
appear on the versionchanged line after the colon, which combined with the
blank space before the bulleted list just looks wrong.  I also tried the
current single-line-three-sentences version with bullet characters before each
sentence, and I almost went with that as it made it clear that the three
sentences are independent.  But I decided to just go with the sentences for
simplicity reasons.

Doc/library/unittest.rst

@@ -239,9 +239,10 @@ Test Discovery
 
 Unittest supports simple test discovery. In order to be compatible with test
 discovery, all of the test files must be :ref:`modules <tut-modules>` or
-:ref:`packages <tut-packages>` importable from the top-level directory of
-the project (this means that their filenames must be valid
-:ref:`identifiers <identifiers>`).
+:ref:`packages <tut-packages>` (including :term:`namespace packages
+<namespace package>`) importable from the top-level directory of
+the project (this means that their filenames must be valid :ref:`identifiers
+<identifiers>`).
 
 Test discovery is implemented in :meth:`TestLoader.discover`, but can also be
 used from the command line. The basic command-line usage is::
@@ -306,6 +307,9 @@ as the start directory.
 Test modules and packages can customize test loading and discovery by through
 the `load_tests protocol`_.
 
+.. versionchanged:: 3.4
+   Test discovery supports :term:`namespace packages <namespace package>`.
+
 
 .. _organizing-tests:
 
@@ -1655,11 +1659,10 @@ Loading and running tests
       .. versionchanged:: 3.4
          Modules that raise :exc:`SkipTest` on import are recorded as skips,
            not errors.
-
-      .. versionchanged:: 3.4
-         Paths are sorted before being imported to ensure execution order for a
-         given test suite is the same even if the underlying file system's ordering
-         is not dependent on file name like in ext3/4.
+         Discovery works for :term:`namespace packages <namespace package>`.
+         Paths are sorted before being imported so that execution order is
+           the same even if the underlying file system's ordering is not
+           dependent on file name.
 
 
    The following attributes of a :class:`TestLoader` can be configured either by

Doc/whatsnew/3.4.rst

@@ -1355,6 +1355,9 @@ context manager can be queried for the :class:`~logging.LogRecord`\ s and/or
 formatted messages that were logged.  (Contributed by Antoine Pitrou in
 :issue:`18937`.)
 
+Test discovery now works with namespace packages (Contributed by Claudiu Popa
+in :issue:`17457`.)
+
 
 venv
 ----