diff --git a/tests/unit/test_is_test_file.py b/tests/unit/test_is_test_file.py
index ac2a7c9f4..4a542f48e 100644
--- a/tests/unit/test_is_test_file.py
+++ b/tests/unit/test_is_test_file.py
@@ -18,6 +18,42 @@
         ("ApiMock.java", True),
         ("ApiMocks.java", True),
         (".github/workflows/ci.yml", True),
+        # Snapshot files
+        ("__snapshots__/Button.test.tsx.snap", True),
+        ("component.snap", True),
+        ("src/__snapshots__/Header.test.js.snap", True),
+        ("component.spec.snap", True),
+        ("component.test.snap", True),
+        # Fixtures
+        ("__fixtures__/user.json", True),
+        ("src/__fixtures__/data.json", True),
+        ("fixtures/sample_data.json", True),
+        ("tests/fixtures/user.json", True),
+        ("user.fixture.ts", True),
+        ("data.fixture.js", True),
+        # Test config files
+        ("jest.config.js", True),
+        ("jest.config.ts", True),
+        ("vitest.config.ts", True),
+        ("vitest.config.js", True),
+        ("karma.conf.js", True),
+        # Test helpers
+        ("setupTests.js", True),
+        ("setupTests.ts", True),
+        ("testSetup.ts", True),
+        ("src/testSetup.ts", True),
+        ("test-setup.js", True),
+        ("test_setup.py", True),
+        ("test-utils/helpers.js", True),
+        ("src/test-utils/api.ts", True),
+        ("test_helpers/utils.py", True),
+        ("test_utils/database.py", True),
+        # Storybook
+        ("Button.stories.tsx", True),
+        ("Header.stories.js", True),
+        ("stories/Header.tsx", True),
+        ("src/stories/Button.tsx", True),
+        # Should NOT be test files
         ("README.md", False),
         ("main.py", False),
         ("utils/file.py", False),
diff --git a/utils/files/is_test_file.py b/utils/files/is_test_file.py
index 274984657..832a74b66 100644
--- a/utils/files/is_test_file.py
+++ b/utils/files/is_test_file.py
@@ -41,6 +41,29 @@ def is_test_file(filename: str) -> bool:
         r"\.mock\.",  # api.mock.ts, database.mock.js
         r"mock\.",  # ApiMock.java, DatabaseMock.cs
         r"mocks\.",  # ApiMocks.java, DatabaseMocks.cs
+        # Snapshot files (Jest, Vitest, etc.)
+        r"/__snapshots__/",  # __snapshots__/Button.test.tsx.snap
+        r"\.snap$",  # any .snap file
+        # Test fixtures and data
+        r"(^|/)__fixtures__/",  # __fixtures__/user.json
+        r"(^|/)fixtures/",  # fixtures/sample_data.json
+        r"\.fixture\.",  # user.fixture.ts
+        # Test configuration files
+        r"jest\.config\.",  # jest.config.js, jest.config.ts
+        r"vitest\.config\.",  # vitest.config.js
+        r"karma\.conf\.",  # karma.conf.js
+        r"\.spec\.snap$",  # component.spec.snap
+        r"\.test\.snap$",  # component.test.snap
+        # Test helpers and utilities
+        r"(^|/)test[-_]utils?/",  # test-utils/, test_utils/
+        r"(^|/)test[-_]helpers?/",  # test-helpers/, test_helper/
+        r"(^|/)setuptests\.",  # setupTests.js, setupTests.ts
+        r"(^|/)testsetup\.",  # testSetup.js, testSetup.ts
+        r"^testsetup\.",  # testSetup.js at root
+        r"(^|/)test[-_]setup\.",  # test-setup.js, test_setup.py
+        # Storybook files (visual testing)
+        r"\.stories\.",  # Button.stories.tsx
+        r"(^|/)stories/",  # stories/Button.tsx
         # Common test file names
         r"^test\.",  # test.js, test.py
         r"^spec\.",  # spec.rb, spec.js