Add discover_imports in conf, don't collect imported classes named Test* closes #12749`

AUTHORS

@@ -400,6 +400,7 @@ Stefanie Molin
 Stefano Taschini
 Steffen Allner
 Stephan Obermann
+Sven
 Sven-Hendrik Haase
 Sviatoslav Sydorenko
 Sylvain Marié

changelog/12749.feature.rst

@@ -0,0 +1,5 @@
+New :confval:`collect_imported_tests`: when enabled (the default) pytest will collect classes/functions in test modules even if they are imported from another file.
+
+Setting this to False will make pytest collect classes/functions from test files only if they are defined in that file (as opposed to imported there).
+
+-- by :user:`FreerGit`

doc/en/reference/reference.rst

@@ -1301,6 +1301,20 @@ passed multiple times. The expected format is ``name=value``. For example::
    variables, that will be expanded. For more information about cache plugin
    please refer to :ref:`cache_provider`.
 
+.. confval:: collect_imported_tests
+
+   .. versionadded:: 8.4
+
+   Setting this to ``false`` will make pytest collect classes/functions from test
+   files only if they are defined in that file (as opposed to imported there).
+
+   .. code-block:: ini
+
+        [pytest]
+        collect_imported_tests = false
+
+   Default: ``true``
+
 .. confval:: consider_namespace_packages
 
    Controls if pytest should attempt to identify `namespace packages <https://packaging.python.org/en/latest/guides/packaging-namespace-packages>`__
@@ -1838,11 +1852,8 @@ passed multiple times. The expected format is ``name=value``. For example::
 
        pytest testing doc
 
-
 .. confval:: tmp_path_retention_count
 
-
-
    How many sessions should we keep the `tmp_path` directories,
    according to `tmp_path_retention_policy`.
 

src/_pytest/main.py

@@ -78,6 +78,12 @@ def pytest_addoption(parser: Parser) -> None:
         type="args",
         default=[],
     )
+    parser.addini(
+        "collect_imported_tests",
+        "Whether to collect tests in imported modules outside `testpaths`",
+        type="bool",
+        default=True,
+    )
     group = parser.getgroup("general", "Running and selection options")
     group._addoption(
         "-x",

src/_pytest/python.py

@@ -416,6 +416,15 @@
                 if name in seen:
                     continue
                 seen.add(name)
+
+                if not self.session.config.getini("collect_imported_tests"):
+                    # Do not collect imported functions
+                    if inspect.isfunction(obj) and isinstance(self, Module):
+                        fn_defined_at = obj.__module__
+                        in_module = self._getobj().__name__
+                        if fn_defined_at != in_module:
+                            continue
+
                 res = ihook.pytest_pycollect_makeitem(
                     collector=self, name=name, obj=obj
                 )
@@ -741,6 +750,16 @@
         return self.obj()
 
     def collect(self) -> Iterable[nodes.Item | nodes.Collector]:
+        if not self.config.getini("collect_imported_tests"):
+            # This entire branch will discard (not collect) a class
+            # if it is imported (defined in a different module)
+            if isinstance(self, Class) and isinstance(self.parent, Module):
+                if inspect.isclass(self._getobj()):
+                    class_defined_at = self._getobj().__module__
+                    in_module = self.parent._getobj().__name__
+                    if class_defined_at != in_module:
+                        return []
+
         if not safe_getattr(self.obj, "__test__", True):
             return []
         if hasinit(self.obj):