feat(testing): expose pytest marks as tags in Test Explorer

[andravin]

Extract pytest marks (e.g., @pytest.mark.slow, @pytest.mark.integration) during test discovery and expose them as VS Code TestTags with IDs like "mark.slow", "mark.integration". This enables filtering tests by marks in the Test Explorer UI using @python-tests:mark.slow syntax.

Changes:

• Add tags field to TestItem TypedDict in pytest plugin
• Extract marks from test_case.own_markers in create_test_node()
• Add tags field to DiscoveredTestItem TypeScript type
• Create TestTag objects from marks in populateTestTree()

Fixes #20350

[andravin]

@microsoft-github-policy-service agree

[andravin]

[andravin]

Tested with v2026.0.0 because main has build issues.

As pictured in the above screenshot, I created test file with @pytest.mark.integration, @pytest.mark.slow, etc, and these appeared in the TEST EXPLORER filter as @python-tests:mark.integration, @python-tests:mark.slow, etc.

[andravin]

For testers: A prebuilt VSIX is available at https://github.com/andravin/vscode-python/releases

Install with:

code --install-extension ms-python-insiders.vsix

If you prefer to build from source:

git clone https://github.com/andravin/vscode-python.git
cd vscode-python
git checkout feature/pytest-marks-as-tags-release
npm install && npm run package
code --install-extension ms-python-insiders.vsix

Note: This replaces the official Python extension. Uninstall and reinstall from the marketplace to revert.

[andravin]

Tested against main. Unit tests have been added.

[Copilot]

Pull request overview

This PR adds end-to-end support for exposing pytest marks (e.g. @pytest.mark.slow) as VS Code Test Explorer tags by extracting marks during pytest discovery (Python-side), carrying them through the discovery payload (shared types), and attaching them to TestItem.tags during tree population (TypeScript-side).

Changes:

• Extend pytest discovery payloads to include a tags field on discovered test items, populated from test_case.own_markers (excluding parametrize, with deduplication).
• Extend the shared TypeScript discovery types and update populateTestTree() to convert those tags into VS Code tag IDs like mark.<name>.
• Add coverage in both TS unit tests and Python discovery tests + fixtures for marked tests.

Show a summary per file

File	Description
src/client/testing/testController/common/utils.ts	Maps discovered pytest tag strings into TestItem.tags entries with mark. prefix.
src/client/testing/testController/common/types.ts	Adds optional tags?: string[] to the discovered test item shape.
src/test/testing/testController/utils.unit.test.ts	Adds unit tests verifying populateTestTree() behavior for mark tags and empty/undefined tags.
python_files/vscode_pytest/init.py	Extracts pytest marks from collected items and emits them as a tags list on discovery test items.
python_files/tests/pytestadapter/test_discovery.py	Adds a discovery test to validate mark-to-tags behavior (including dedupe and excluding parametrize).
python_files/tests/pytestadapter/expected_discovery_test_output.py	Adds expected discovery tree output for the new marks fixture (including tags).
python_files/tests/pytestadapter/.data/test_marks.py	New fixture file containing marked/parametrized tests used by the discovery test.

Review details

Comments suppressed due to low confidence (1)

src/test/testing/testController/utils.unit.test.ts:677

• The expected mark tags are asserted in slow then integration order, but the Python discovery expectation for multiple marks is integration then slow. If the extension preserves the discovery order (as populateTestTree currently does), this assertion should reflect that ordering to avoid failing when fed real discovery data.

        assert.deepStrictEqual(mockTestItem.tags, [
            RunTestTag,
            DebugTestTag,
            { id: 'mark.slow' },
            { id: 'mark.integration' },

• Files reviewed: 7/7 changed files
• Comments generated: 2
• Review effort level: Low