Invoke invalidate_caches in tests exhibiting refleaks.

Author: jaraco

Lib/test/test_importlib/test_main.py

@@ -2,6 +2,7 @@
 import pickle
 import unittest
 import warnings
+import importlib
 import importlib.metadata
 import contextlib
 from test.support import os_helper
@@ -37,6 +38,9 @@ def suppress_known_deprecation():
 class BasicTests(fixtures.DistInfoPkg, unittest.TestCase):
     version_pattern = r'\d+\.\d+(\.\d)?'
 
+    def tearDown(self):
+        importlib.invalidate_caches()
+
     def test_retrieves_version_of_self(self):
         dist = Distribution.from_name('distinfo-pkg')
         assert isinstance(dist.version, str)
@@ -75,6 +79,7 @@ def test_invalid_inputs_to_from_name(self, name):
 
 
 class ImportTests(fixtures.DistInfoPkg, unittest.TestCase):
+
     def test_import_nonexistent_module(self):
         # Ensure that the MetadataPathFinder does not crash an import of a
         # non-existent module.

Lib/test/test_importlib/test_metadata_api.py

@@ -37,6 +37,9 @@ class APITests(
 ):
     version_pattern = r'\d+\.\d+(\.\d)?'
 
+    def tearDown(self):
+        importlib.invalidate_caches()
+
     def test_retrieves_version_of_self(self):
         pkg_version = version('egginfo-pkg')
         assert isinstance(pkg_version, str)