test: Move setup and teardown to a autouse fixture

Pytest docs say that setup and teardown functions run prior to fixtures,
therefore the plugin was always patching (being enabled), and strong
guards via fixture cacheing were
making it look like setup and teardown were called at the right time.
By promotoing enable_plugin to a fixture in all cases, and using a
autouse yield fixture to call setup and teardown we can make this under
our full control

Author: Leonidas Loucas

pylint_pytest/checkers/fixture.py

@@ -220,11 +220,6 @@ def patch_add_message(self, msgid, line=None, node=None, args=None,
         '''
         - intercept and discard unwanted warning messages
         '''
-        if not FixtureChecker.enable_plugin:
-            FixtureChecker._original_add_message(
-                self, msgid, line, node, args, confidence, col_offset
-            )
-            return
         # check W0611 unused-import
         if msgid == 'unused-import':
             # actual attribute name is not passed as arg so...dirty hack

tests/base_tester.py

@@ -10,6 +10,7 @@
     # for pylint 1.9
     from pylint.utils import PyLintASTWalker as ASTWalker
 from pylint.checkers import BaseChecker
+import pytest
 
 import pylint_pytest.checkers.fixture
 
@@ -56,14 +57,24 @@ def verify_messages(self, msg_count, msg_id=None):
         pprint(self.MESSAGES)
         assert matched_count == msg_count, f'expecting {msg_count}, actual {matched_count}'
 
-    def setup_method(self):
+    @pytest.fixture(scope="function", autouse=True)
+    def within(self, request, enable_plugin):
+        try:
+            request.instance._setup_method(enable_plugin)
+            yield request.instance
+        finally:
+            request.instance._teardown_method(enable_plugin)
+
+
+    def _setup_method(self, enable_plugin):
         self.linter = UnittestLinter()
-        self.checker = self.CHECKER_CLASS(self.linter)
         self.impacted_checkers = []
 
-        for key, value in self.CONFIG.items():
-            setattr(self.checker.config, key, value)
-        self.checker.open()
+        if enable_plugin:
+            self.checker = self.CHECKER_CLASS(self.linter)
+            for key, value in self.CONFIG.items():
+                setattr(self.checker.config, key, value)
+            self.checker.open()
 
         for checker_class in self.IMPACTED_CHECKER_CLASSES:
             checker = checker_class(self.linter)
@@ -72,8 +83,9 @@ def setup_method(self):
             checker.open()
             self.impacted_checkers.append(checker)
 
-    def teardown_method(self):
-        self.checker.close()
+    def _teardown_method(self, enable_plugin):
+        if enable_plugin:
+            self.checker.close()
         for checker in self.impacted_checkers:
             checker.close()
 

tests/test_pytest_fixture_positional_arguments.py

@@ -1,3 +1,5 @@
+import pytest
+
 from base_tester import BasePytestTester
 from pylint_pytest.checkers.fixture import FixtureChecker
 
@@ -6,14 +8,18 @@ class TestDeprecatedPytestFixtureScopeAsPositionalParam(BasePytestTester):
     CHECKER_CLASS = FixtureChecker
     MSG_ID = 'deprecated-positional-argument-for-pytest-fixture'
 
-    def test_with_args_scope(self):
-        self.run_linter(enable_plugin=True)
+    @pytest.fixture
+    def enable_plugin(self):
+        return True
+
+    def test_with_args_scope(self, enable_plugin):
+        self.run_linter(enable_plugin)
         self.verify_messages(1)
 
-    def test_with_kwargs_scope(self):
-        self.run_linter(enable_plugin=True)
+    def test_with_kwargs_scope(self, enable_plugin):
+        self.run_linter(enable_plugin)
         self.verify_messages(0)
 
-    def test_without_scope(self):
-        self.run_linter(enable_plugin=True)
+    def test_without_scope(self, enable_plugin):
+        self.run_linter(enable_plugin)
         self.verify_messages(0)

tests/test_pytest_mark_for_fixtures.py

@@ -1,3 +1,5 @@
+import pytest
+
 from base_tester import BasePytestTester
 from pylint_pytest.checkers.fixture import FixtureChecker
 
@@ -6,26 +8,30 @@ class TestPytestMarkUsefixtures(BasePytestTester):
     CHECKER_CLASS = FixtureChecker
     MSG_ID = 'useless-pytest-mark-decorator'
 
-    def test_mark_usefixture_using_for_test(self):
-        self.run_linter(enable_plugin=True)
+    @pytest.fixture
+    def enable_plugin(self):
+        return True
+
+    def test_mark_usefixture_using_for_test(self, enable_plugin):
+        self.run_linter(enable_plugin)
         self.verify_messages(0)
 
-    def test_mark_usefixture_using_for_class(self):
-        self.run_linter(enable_plugin=True)
+    def test_mark_usefixture_using_for_class(self, enable_plugin):
+        self.run_linter(enable_plugin)
         self.verify_messages(0)
 
-    def test_mark_usefixture_using_for_fixture_attribute(self):
-        self.run_linter(enable_plugin=True)
+    def test_mark_usefixture_using_for_fixture_attribute(self, enable_plugin):
+        self.run_linter(enable_plugin)
         self.verify_messages(2)
 
-    def test_mark_usefixture_using_for_fixture_function(self):
-        self.run_linter(enable_plugin=True)
+    def test_mark_usefixture_using_for_fixture_function(self, enable_plugin):
+        self.run_linter(enable_plugin)
         self.verify_messages(2)
 
-    def test_other_marks_using_for_fixture(self):
-        self.run_linter(enable_plugin=True)
+    def test_other_marks_using_for_fixture(self, enable_plugin):
+        self.run_linter(enable_plugin)
         self.verify_messages(4)
 
-    def test_not_pytest_marker(self):
-        self.run_linter(enable_plugin=True)
+    def test_not_pytest_marker(self, enable_plugin):
+        self.run_linter(enable_plugin)
         self.verify_messages(0)

tests/test_pytest_yield_fixture.py

@@ -1,3 +1,5 @@
+import pytest
+
 from base_tester import BasePytestTester
 from pylint_pytest.checkers.fixture import FixtureChecker
 
@@ -7,10 +9,14 @@ class TestDeprecatedPytestYieldFixture(BasePytestTester):
     IMPACTED_CHECKER_CLASSES = []
     MSG_ID = 'deprecated-pytest-yield-fixture'
 
-    def test_smoke(self):
-        self.run_linter(enable_plugin=True)
+    @pytest.fixture
+    def enable_plugin(self):
+        return True
+
+    def test_smoke(self, enable_plugin):
+        self.run_linter(enable_plugin)
         self.verify_messages(1)
 
-    def test_func(self):
-        self.run_linter(enable_plugin=True)
+    def test_func(self, enable_plugin):
+        self.run_linter(enable_plugin)
         self.verify_messages(2)