Merge branch 'pytest-dev:main' into remove-eq-format

src/_pytest/hookspec.py

@@ -33,10 +33,10 @@ if TYPE_CHECKING:
     from _pytest.nodes import Collector
     from _pytest.nodes import Item
     from _pytest.outcomes import Exit
+    from _pytest.python import Class
     from _pytest.python import Function
     from _pytest.python import Metafunc
     from _pytest.python import Module
-    from _pytest.python import PyCollector
     from _pytest.reports import CollectReport
     from _pytest.reports import TestReport
     from _pytest.runner import CallInfo
@@ -359,7 +359,7 @@ def pytest_pycollect_makemodule(
 
 @hookspec(firstresult=True)
 def pytest_pycollect_makeitem(
-    collector: "PyCollector", name: str, obj: object
+    collector: Union["Module", "Class"], name: str, obj: object
 ) -> Union[None, "Item", "Collector", List[Union["Item", "Collector"]]]:
     """Return a custom item/collector for a Python object in a module, or None.
 

src/_pytest/python.py

@@ -224,11 +224,15 @@ def pytest_pycollect_makemodule(module_path: Path, parent) -> "Module":
 
 
 @hookimpl(trylast=True)
-def pytest_pycollect_makeitem(collector: "PyCollector", name: str, obj: object):
+def pytest_pycollect_makeitem(
+    collector: Union["Module", "Class"], name: str, obj: object
+) -> Union[None, nodes.Item, nodes.Collector, List[Union[nodes.Item, nodes.Collector]]]:
+    assert isinstance(collector, (Class, Module)), type(collector)
     # Nothing was collected elsewhere, let's do it here.
     if safe_isclass(obj):
         if collector.istestclass(obj, name):
-            return Class.from_parent(collector, name=name, obj=obj)
+            klass: Class = Class.from_parent(collector, name=name, obj=obj)
+            return klass
     elif collector.istestfunction(obj, name):
         # mock seems to store unbound methods (issue473), normalize it.
         obj = getattr(obj, "__func__", obj)
@@ -247,15 +251,16 @@ def pytest_pycollect_makeitem(collector: "PyCollector", name: str, obj: object):
             )
         elif getattr(obj, "__test__", True):
             if is_generator(obj):
-                res = Function.from_parent(collector, name=name)
+                res: Function = Function.from_parent(collector, name=name)
                 reason = "yield tests were removed in pytest 4.0 - {name} will be ignored".format(
                     name=name
                 )
                 res.add_marker(MARK_GEN.xfail(run=False, reason=reason))
                 res.warn(PytestCollectionWarning(reason))
+                return res
             else:
-                res = list(collector._genfunctions(name, obj))
-            return res
+                return list(collector._genfunctions(name, obj))
+    return None
 
 
 class PyobjMixin(nodes.Node):

src/_pytest/unittest.py

@@ -27,7 +27,7 @@ from _pytest.outcomes import skip
 from _pytest.outcomes import xfail
 from _pytest.python import Class
 from _pytest.python import Function
-from _pytest.python import PyCollector
+from _pytest.python import Module
 from _pytest.runner import CallInfo
 from _pytest.scope import Scope
 
@@ -42,7 +42,7 @@ if TYPE_CHECKING:
 
 
 def pytest_pycollect_makeitem(
-    collector: PyCollector, name: str, obj: object
+    collector: Union[Module, Class], name: str, obj: object
 ) -> Optional["UnitTestCase"]:
     # Has unittest been imported and is obj a subclass of its TestCase?
     try:

testing/test_session.py

@@ -335,6 +335,54 @@ def test_sessionfinish_with_start(pytester: Pytester) -> None:
     assert res.ret == ExitCode.NO_TESTS_COLLECTED
 
 
+def test_collection_args_do_not_duplicate_modules(pytester: Pytester) -> None:
+    """Test that when multiple collection args are specified on the command line
+    for the same module, only a single Module collector is created.
+
+    Regression test for #723, #3358.
+    """
+    pytester.makepyfile(
+        **{
+            "d/test_it": """
+                def test_1(): pass
+                def test_2(): pass
+                """
+        }
+    )
+
+    result = pytester.runpytest(
+        "--collect-only",
+        "d/test_it.py::test_1",
+        "d/test_it.py::test_2",
+    )
+    result.stdout.fnmatch_lines(
+        [
+            "<Module d/test_it.py>",
+            "  <Function test_1>",
+            "  <Function test_2>",
+        ],
+        consecutive=True,
+    )
+
+    # Different, but related case.
+    result = pytester.runpytest(
+        "--collect-only",
+        "--keep-duplicates",
+        "d",
+        "d",
+    )
+    result.stdout.fnmatch_lines(
+        [
+            "<Module d/test_it.py>",
+            "  <Function test_1>",
+            "  <Function test_2>",
+            "  <Function test_1>",
+            "  <Function test_2>",
+        ],
+        consecutive=True,
+    )
+
+
 @pytest.mark.parametrize("path", ["root", "{relative}/root", "{environment}/root"])
 def test_rootdir_option_arg(
     pytester: Pytester, monkeypatch: MonkeyPatch, path: str