Stop injecting in pytest_collection_modifyitems

Author: dmtucker

src/pytest_mypy.py

@@ -125,26 +125,16 @@ def from_parent(cls, *args, **kwargs):
     def collect(self):
         """Create a MypyFileItem for the File."""
         yield MypyFileItem.from_parent(parent=self, name=nodeid_name)
-
-
-@pytest.hookimpl(hookwrapper=True, trylast=True)
-def pytest_collection_modifyitems(session, config, items):
-    """
-    Add a MypyStatusItem if any MypyFileItems were collected.
-
-    Since mypy might check files that were not collected,
-    pytest could pass even though mypy failed!
-    To prevent that, add an explicit check for the mypy exit status.
-
-    This should execute as late as possible to avoid missing any
-    MypyFileItems injected by other pytest_collection_modifyitems
-    implementations.
-    """
-    yield
-    if any(isinstance(item, MypyFileItem) for item in items):
-        items.append(
-            MypyStatusItem.from_parent(parent=session, name=nodeid_name),
-        )
+        # Since mypy might check files that were not collected,
+        # pytest could pass even though mypy failed!
+        # To prevent that, add an explicit check for the mypy exit status.
+        if not any(
+                isinstance(item, MypyStatusItem) for item in self.session.items
+        ):
+            yield MypyStatusItem.from_parent(
+                parent=self,
+                name=nodeid_name + "-status",
+            )
 
 
 class MypyItem(pytest.Item):

tests/test_pytest_mypy.py

@@ -214,38 +214,6 @@ def pytest_configure(config):
     assert result.ret == 0
 
 
-def test_pytest_collection_modifyitems(testdir, xdist_args):
-    """
-    Verify that collected files which are removed in a
-    pytest_collection_modifyitems implementation are not
-    checked by mypy.
-
-    This would also fail if a MypyStatusItem were injected
-    despite there being no MypyFileItems.
-    """
-    testdir.makepyfile(conftest='''
-        def pytest_collection_modifyitems(session, config, items):
-            plugin = config.pluginmanager.getplugin('mypy')
-            for mypy_item_i in reversed([
-                    i
-                    for i, item in enumerate(items)
-                    if isinstance(item, plugin.MypyFileItem)
-            ]):
-                items.pop(mypy_item_i)
-    ''')
-    testdir.makepyfile('''
-        def pyfunc(x: int) -> str:
-            return x * 2
-
-        def test_pass():
-            pass
-    ''')
-    result = testdir.runpytest_subprocess('--mypy', *xdist_args)
-    test_count = 1
-    result.assert_outcomes(passed=test_count)
-    assert result.ret == 0
-
-
 def test_mypy_indirect(testdir, xdist_args):
     """Verify that uncollected files checked by mypy cause a failure."""
     testdir.makepyfile(bad='''
@@ -259,38 +227,6 @@ def pyfunc(x: int) -> str:
     assert result.ret != 0
 
 
-def test_mypy_indirect_inject(testdir, xdist_args):
-    """
-    Verify that uncollected files checked by mypy because of a MypyFileItem
-    injected in pytest_collection_modifyitems cause a failure.
-    """
-    testdir.makepyfile(bad='''
-        def pyfunc(x: int) -> str:
-            return x * 2
-    ''')
-    testdir.makepyfile(good='''
-        import bad
-    ''')
-    testdir.makepyfile(conftest='''
-        import py
-        import pytest
-
-        @pytest.hookimpl(trylast=True)  # Inject as late as possible.
-        def pytest_collection_modifyitems(session, config, items):
-            plugin = config.pluginmanager.getplugin('mypy')
-            items.append(
-                plugin.MypyFileItem.from_parent(
-                    parent=session,
-                    name=str(py.path.local('good.py')),
-                ),
-            )
-    ''')
-    name = 'empty'
-    testdir.mkdir(name)
-    result = testdir.runpytest_subprocess('--mypy', *xdist_args, name)
-    assert result.ret != 0
-
-
 def test_api_error_formatter(testdir, xdist_args):
     """Ensure that the plugin can be configured in a conftest.py."""
     testdir.makepyfile(bad='''