Unit Tests

When you're working in the VS Code repository and need to run unit tests, this skill walks you through the runTests tool first, then falls back to the shell scripts (test.sh or test.bat) when necessary. It covers the practical stuff: passing file paths, filtering tests with grep, running globs, and collecting coverage. The guidance on bare file paths versus the explicit --run flag is helpful since the scripts accept both. One thing to note: these scripts only handle unit tests, not integration tests, and you need to have your build running or you'll be testing stale compiled output. It's a solid reference for the common flags and patterns without having to dig through script source code.

skills.sh installs: 241
GitHub stars: 195.3K
last updated: Aug 21, 2026

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Install

$ npx -y skills add microsoft/vscode --skill unit-tests --agent claude-code

Installs into .claude/skills of the current project.

Files

Running Unit Tests

Preferred: Use the `runTests` tool

If the runTests tool is available, prefer it over running shell commands. It provides structured output with detailed pass/fail information and supports filtering by file and test name.

Pass absolute paths to test files via the files parameter.
Pass test names via the testNames parameter to filter which tests run.
Set mode="coverage" to collect coverage.

The tool runs tests discovered by VS Code's registered test controllers; it does not compile the repository or invoke a shell test command. If discovery is unavailable, pending, or reports no executed tests, treat the request as unvalidated and use the repository's configured test command. Review per-file and test-name diagnostics for partially matched requests instead of repeatedly checking the same paths.

Example (conceptual): run tests in src/vs/editor/test/common/model/model.test.ts with test name filter "should split lines".