Add consider_namespace_packages ini option

Fix pytest-dev#11475

src/_pytest/config/__init__.py

@@ -547,6 +547,8 @@ def _set_initial_conftests(
         confcutdir: Optional[Path],
         invocation_dir: Path,
         importmode: Union[ImportMode, str],
+        *,
+        consider_namespace_packages: bool,
     ) -> None:
         """Load initial conftest files given a preparsed "namespace".
 
@@ -572,10 +574,20 @@ def _set_initial_conftests(
             # Ensure we do not break if what appears to be an anchor
             # is in fact a very long option (#10169, #11394).
             if safe_exists(anchor):
-                self._try_load_conftest(anchor, importmode, rootpath)
+                self._try_load_conftest(
+                    anchor,
+                    importmode,
+                    rootpath,
+                    consider_namespace_packages=consider_namespace_packages,
+                )
                 foundanchor = True
         if not foundanchor:
-            self._try_load_conftest(invocation_dir, importmode, rootpath)
+            self._try_load_conftest(
+                invocation_dir,
+                importmode,
+                rootpath,
+                consider_namespace_packages=consider_namespace_packages,
+            )
 
     def _is_in_confcutdir(self, path: Path) -> bool:
         """Whether to consider the given path to load conftests from."""
@@ -593,17 +605,37 @@ def _is_in_confcutdir(self, path: Path) -> bool:
         return path not in self._confcutdir.parents
 
     def _try_load_conftest(
-        self, anchor: Path, importmode: Union[str, ImportMode], rootpath: Path
+        self,
+        anchor: Path,
+        importmode: Union[str, ImportMode],
+        rootpath: Path,
+        *,
+        consider_namespace_packages: bool,
     ) -> None:
-        self._loadconftestmodules(anchor, importmode, rootpath)
+        self._loadconftestmodules(
+            anchor,
+            importmode,
+            rootpath,
+            consider_namespace_packages=consider_namespace_packages,
+        )
         # let's also consider test* subdirs
         if anchor.is_dir():
             for x in anchor.glob("test*"):
                 if x.is_dir():
-                    self._loadconftestmodules(x, importmode, rootpath)
+                    self._loadconftestmodules(
+                        x,
+                        importmode,
+                        rootpath,
+                        consider_namespace_packages=consider_namespace_packages,
+                    )
 
     def _loadconftestmodules(
-        self, path: Path, importmode: Union[str, ImportMode], rootpath: Path
+        self,
+        path: Path,
+        importmode: Union[str, ImportMode],
+        rootpath: Path,
+        *,
+        consider_namespace_packages: bool,
     ) -> None:
         if self._noconftest:
             return
@@ -620,7 +652,12 @@ def _loadconftestmodules(
             if self._is_in_confcutdir(parent):
                 conftestpath = parent / "conftest.py"
                 if conftestpath.is_file():
-                    mod = self._importconftest(conftestpath, importmode, rootpath)
+                    mod = self._importconftest(
+                        conftestpath,
+                        importmode,
+                        rootpath,
+                        consider_namespace_packages=consider_namespace_packages,
+                    )
                     clist.append(mod)
         self._dirpath2confmods[directory] = clist
 
@@ -642,7 +679,12 @@ def _rget_with_confmod(
         raise KeyError(name)
 
     def _importconftest(
-        self, conftestpath: Path, importmode: Union[str, ImportMode], rootpath: Path
+        self,
+        conftestpath: Path,
+        importmode: Union[str, ImportMode],
+        rootpath: Path,
+        *,
+        consider_namespace_packages: bool,
     ) -> types.ModuleType:
         conftestpath_plugin_name = str(conftestpath)
         existing = self.get_plugin(conftestpath_plugin_name)
@@ -661,7 +703,12 @@ def _importconftest(
                 pass
 
         try:
-            mod = import_path(conftestpath, mode=importmode, root=rootpath)
+            mod = import_path(
+                conftestpath,
+                mode=importmode,
+                root=rootpath,
+                consider_namespace_packages=consider_namespace_packages,
+            )
         except Exception as e:
             assert e.__traceback__ is not None
             raise ConftestImportFailure(conftestpath, cause=e) from e
@@ -1177,6 +1224,9 @@ def pytest_load_initial_conftests(self, early_config: "Config") -> None:
             confcutdir=early_config.known_args_namespace.confcutdir,
             invocation_dir=early_config.invocation_params.dir,
             importmode=early_config.known_args_namespace.importmode,
+            consider_namespace_packages=early_config.getini(
+                "consider_namespace_packages"
+            ),
         )
 
     def _initini(self, args: Sequence[str]) -> None:

src/_pytest/main.py

@@ -222,6 +222,12 @@ def pytest_addoption(parser: Parser) -> None:
         help="Prepend/append to sys.path when importing test modules and conftest "
         "files. Default: prepend.",
     )
+    parser.addini(
+        "consider_namespace_packages",
+        type="bool",
+        default=False,
+        help="Consider namespace packages when resolving module names during import",
+    )
 
     group = parser.getgroup("debugconfig", "test session debugging and configuration")
     group.addoption(

src/_pytest/pathlib.py

@@ -488,6 +488,7 @@ def import_path(
     *,
     mode: Union[str, ImportMode] = ImportMode.prepend,
     root: Path,
+    consider_namespace_packages: bool,
 ) -> ModuleType:
     """
     Import and return a module from the given path, which can be a file (a module) or
@@ -515,6 +516,9 @@ def import_path(
         a unique name for the module being imported so it can safely be stored
         into ``sys.modules``.
 
+    :param consider_namespace_packages:
+        If True, consider namespace packages when resolving module names.
+
     :raises ImportPathMismatchError:
         If after importing the given `path` and the module `__file__`
         are different. Only raised in `prepend` and `append` modes.
@@ -530,7 +534,7 @@ def import_path(
         # without touching sys.path.
         try:
             pkg_root, module_name = resolve_pkg_root_and_module_name(
-                path, consider_ns_packages=True
+                path, consider_namespace_packages=consider_namespace_packages
             )
         except CouldNotResolvePathError:
             pass
@@ -556,7 +560,7 @@ def import_path(
 
     try:
         pkg_root, module_name = resolve_pkg_root_and_module_name(
-            path, consider_ns_packages=True
+            path, consider_namespace_packages=consider_namespace_packages
         )
     except CouldNotResolvePathError:
         pkg_root, module_name = path.parent, path.stem
@@ -674,7 +678,7 @@ def module_name_from_path(path: Path, root: Path) -> str:
     # Module names cannot contain ".", normalize them to "_". This prevents
     # a directory having a "." in the name (".env.310" for example) causing extra intermediate modules.
     # Also, important to replace "." at the start of paths, as those are considered relative imports.
-    path_parts = [x.replace(".", "_") for x in path_parts]
+    path_parts = tuple(x.replace(".", "_") for x in path_parts)
 
     return ".".join(path_parts)
 
@@ -738,7 +742,7 @@ def resolve_package_path(path: Path) -> Optional[Path]:
 
 
 def resolve_pkg_root_and_module_name(
-    path: Path, *, consider_ns_packages: bool = False
+    path: Path, *, consider_namespace_packages: bool = False
 ) -> Tuple[Path, str]:
     """
     Return the path to the directory of the root package that contains the
@@ -753,7 +757,7 @@ def resolve_pkg_root_and_module_name(
 
     Passing the full path to `models.py` will yield Path("src") and "app.core.models".
 
-    If consider_ns_packages is True, then we additionally check upwards in the hierarchy
+    If consider_namespace_packages is True, then we additionally check upwards in the hierarchy
     until we find a directory that is reachable from sys.path, which marks it as a namespace package:
 
     https://packaging.python.org/en/latest/guides/packaging-namespace-packages
@@ -764,7 +768,7 @@ def resolve_pkg_root_and_module_name(
     if pkg_path is not None:
         pkg_root = pkg_path.parent
         # https://packaging.python.org/en/latest/guides/packaging-namespace-packages/
-        if consider_ns_packages:
+        if consider_namespace_packages:
             # Go upwards in the hierarchy, if we find a parent path included
             # in sys.path, it means the package found by resolve_package_path()
             # actually belongs to a namespace package.

src/_pytest/python.py

@@ -516,7 +516,12 @@ def importtestmodule(
     # We assume we are only called once per module.
     importmode = config.getoption("--import-mode")
     try:
-        mod = import_path(path, mode=importmode, root=config.rootpath)
+        mod = import_path(
+            path,
+            mode=importmode,
+            root=config.rootpath,
+            consider_namespace_packages=config.getini("consider_namespace_packages"),
+        )
     except SyntaxError as e:
         raise nodes.Collector.CollectError(
             ExceptionInfo.from_current().getrepr(style="short")

src/_pytest/runner.py

@@ -380,6 +380,9 @@ def collect() -> List[Union[Item, Collector]]:
                 collector.path,
                 collector.config.getoption("importmode"),
                 rootpath=collector.config.rootpath,
+                consider_namespace_packages=collector.config.getini(
+                    "consider_namespace_packages"
+                ),
             )
 
         return list(collector.collect())

testing/code/test_excinfo.py

@@ -180,7 +180,7 @@ def test_traceback_cut(self) -> None:
     def test_traceback_cut_excludepath(self, pytester: Pytester) -> None:
         p = pytester.makepyfile("def f(): raise ValueError")
         with pytest.raises(ValueError) as excinfo:
-            import_path(p, root=pytester.path).f()  # type: ignore[attr-defined]
+            import_path(p, root=pytester.path, consider_namespace_packages=False).f()  # type: ignore[attr-defined]
         basedir = Path(pytest.__file__).parent
         newtraceback = excinfo.traceback.cut(excludepath=basedir)
         for x in newtraceback:
@@ -543,7 +543,9 @@ def importasmod(source):
             tmp_path.joinpath("__init__.py").touch()
             modpath.write_text(source, encoding="utf-8")
             importlib.invalidate_caches()
-            return import_path(modpath, root=tmp_path)
+            return import_path(
+                modpath, root=tmp_path, consider_namespace_packages=False
+            )
 
         return importasmod
 

testing/code/test_source.py

@@ -296,7 +296,7 @@ def method(self):
     )
     path = tmp_path.joinpath("a.py")
     path.write_text(str(source), encoding="utf-8")
-    mod: Any = import_path(path, root=tmp_path)
+    mod: Any = import_path(path, root=tmp_path, consider_namespace_packages=False)
     s2 = Source(mod.A)
     assert str(source).strip() == str(s2).strip()