update default and add docs

Author: FreerGit

changelog/12749.feature.rst

@@ -1,3 +1,5 @@
-Add :confval:`collect_imported_tests`, when enabled (default is disabled) will make sure to not consider classes/functions which are imported by a test file and contains Test/test_*/*_test.
+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

@@ -1839,9 +1839,17 @@ passed multiple times. The expected format is ``name=value``. For example::
        pytest testing doc
 
 
-.. confval:: tmp_path_retention_count
+.. confval:: collect_imported_tests
+
+   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
 
+.. 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

@@ -82,7 +82,7 @@ def pytest_addoption(parser: Parser) -> None:
         "collect_imported_tests",
         "Whether to collect tests in imported modules outside `testpaths`",
         type="bool",
-        default=False,
+        default=True,
     )
     group = parser.getgroup("general", "Running and selection options")
     group._addoption(
@@ -973,7 +973,7 @@ def genitems(self, node: nodes.Item | nodes.Collector) -> Iterator[nodes.Item]:
         self.trace("genitems", node)
         if isinstance(node, nodes.Item):
             node.ihook.pytest_itemcollected(item=node)
-            if self.config.getini("collect_imported_tests"):
+            if not self.config.getini("collect_imported_tests"):
                 if isinstance(node.parent, Module) and isinstance(node, Function):
                     if inspect.isfunction(node._getobj()):
                         fn_defined_at = node._getobj().__module__
@@ -988,7 +988,7 @@ def genitems(self, node: nodes.Item | nodes.Collector) -> Iterator[nodes.Item]:
             handle_dupes = not (keepduplicates and isinstance(node, nodes.File))
             rep, duplicate = self._collect_one_node(node, handle_dupes)
 
-            if self.config.getini("collect_imported_tests"):
+            if not self.config.getini("collect_imported_tests"):
                 for subnode in rep.result:
                     if isinstance(subnode, Class) and isinstance(
                         subnode.parent, Module

testing/test_collect_imports.py

@@ -55,7 +55,7 @@ def test_collect_imports_disabled(pytester: Pytester) -> None:
         collect_imported_tests = false
     """)
 
-    run_import_class_test(pytester, errors=1)
+    run_import_class_test(pytester, passed=1)
 
 
 def test_collect_imports_default(pytester: Pytester) -> None:
@@ -74,7 +74,7 @@ def test_collect_imports_enabled(pytester: Pytester) -> None:
         collect_imported_tests = true
     """)
 
-    run_import_class_test(pytester, passed=1)
+    run_import_class_test(pytester, errors=1)
 
 
 def run_import_functions_test(
@@ -137,14 +137,32 @@ def test_collect_function_imports_enabled(pytester: Pytester) -> None:
         collect_imported_tests = true
     """)
 
-    run_import_functions_test(pytester, passed=1, errors=0, failed=0)
+    run_import_functions_test(pytester, passed=2, errors=0, failed=1)
 
 
 def test_collect_function_imports_disabled(pytester: Pytester) -> None:
     pytester.makeini("""
         [pytest]
-        testpaths = "tests"
+        # testpaths = "tests"
         collect_imported_tests = false
     """)
 
+    run_import_functions_test(pytester, passed=1, errors=0, failed=0)
+
+
+def test_behaviour_without_testpaths_set_and_false(pytester: Pytester) -> None:
+    pytester.makeini("""
+        [pytest]
+        collect_imported_tests = false
+    """)
+
+    run_import_functions_test(pytester, passed=1, errors=0, failed=0)
+
+
+def test_behaviour_without_testpaths_set_and_true(pytester: Pytester) -> None:
+    pytester.makeini("""
+        [pytest]
+        collect_imported_tests = true
+    """)
+
     run_import_functions_test(pytester, passed=2, errors=0, failed=1)