How do I install the Unit Tests skill?

Run npx skillmds@latest add microsoft/unit-tests in your terminal (requires Node.js), paste this page's agent-chat prompt into Claude, Cursor, or any MCP-connected agent, or download the SKILL.md file and copy it into your agent's skills directory.

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Is Unit Tests free to use?

Yes. Installing skills from SkillMD is free, and the skill stays under its author's original license.

Who published Unit Tests?

Microsoft (@microsoft) published this skill. Their other Agent Skills are listed on their SkillMD profile.

Unit Tests by microsoft — Agent Skill

Name: Unit Tests
Rating: 4.5 (4 reviews)
Author: Microsoft

File contents

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.

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

Fallback: Shell scripts

When the runTests tool is not available (e.g. in CLI environments), use the platform-appropriate script from the repo root:

macOS / Linux: ./scripts/test.sh [options]
Windows: .\scripts\test.bat [options]

These scripts download Electron if needed and launch the Mocha test runner.

Commonly used options

Bare file paths - Run tests from specific files

Pass source file paths directly as positional arguments. The test runner automatically treats bare .ts/.js positional arguments as --run values.

./scripts/test.sh src/vs/editor/test/common/model.test.ts

.\scripts\test.bat src\vs\editor\test\common\model.test.ts

Multiple files:

./scripts/test.sh src/vs/editor/test/common/model.test.ts src/vs/editor/test/common/range.test.ts

`--run <file>` - Run tests from a specific file (explicit form)

Accepts a source file path (starting with src/). The runner strips the src/ prefix and the .ts/.js extension automatically to resolve the compiled module.

./scripts/test.sh --run src/vs/editor/test/common/model.test.ts

Multiple files can be specified by repeating --run:

./scripts/test.sh --run src/vs/editor/test/common/model.test.ts --run src/vs/editor/test/common/range.test.ts

`--grep <pattern>` (aliases: `-g`, `-f`) - Filter tests by name

Runs only tests whose full title matches the pattern (passed to Mocha's --grep).

./scripts/test.sh --grep "should split lines"

Combine with --run to filter tests within a specific file:

./scripts/test.sh --run src/vs/editor/test/common/model.test.ts --grep "should split lines"

`--runGlob <pattern>` (aliases: `--glob`, `--runGrep`) - Run tests matching a glob

Runs all test files matching a glob pattern against the compiled output directory. Useful for running all tests under a feature area.

./scripts/test.sh --runGlob "**/editor/test/**/*.test.js"

Note: the glob runs against compiled .js files in the output directory, not source .ts files.

`--coverage` - Generate a coverage report

./scripts/test.sh --run src/vs/editor/test/common/model.test.ts --coverage

`--timeout <ms>` - Set test timeout

Override the default Mocha timeout for long-running tests.

./scripts/test.sh --run src/vs/editor/test/common/model.test.ts --timeout 10000

Integration tests

Integration tests (files ending in .integrationTest.ts or located in extensions/) are not run by scripts/test.sh. Use scripts/test-integration.sh (or scripts/test-integration.bat) instead. See the integration-tests skill for details.

Compilation requirement

Tests run against compiled JavaScript output. Ensure the VS Code - Build watch task is running or that compilation has completed before running tests. Test failures caused by stale output are a common pitfall.

---name: unit-testsdescription: Use when running unit tests in the VS Code repo. Covers the runTests tool, scripts/test.sh (macOS/Linux) and scripts/test.bat (Windows), and their supported arguments for filtering, globbing, and debugging tests.--- # 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. Example (conceptual): run tests in `src/vs/editor/test/common/model.test.ts` with test name filter `"should split lines"`. ## Fallback: Shell scripts When the `runTests` tool is not available (e.g. in CLI environments), use the platform-appropriate script from the repo root: - **macOS / Linux:** `./scripts/test.sh [options]` - **Windows:** `.\scripts\test.bat [options]` These scripts download Electron if needed and launch the Mocha test runner. ### Commonly used options #### Bare file paths - Run tests from specific files Pass source file paths directly as positional arguments. The test runner automatically treats bare `.ts`/`.js` positional arguments as `--run` values. ```bash ./scripts/test.sh src/vs/editor/test/common/model.test.ts ``` ```bat .\scripts\test.bat src\vs\editor\test\common\model.test.ts ``` Multiple files: ```bash ./scripts/test.sh src/vs/editor/test/common/model.test.ts src/vs/editor/test/common/range.test.ts ``` #### `--run <file>` - Run tests from a specific file (explicit form) Accepts a **source file path** (starting with `src/`). The runner strips the `src/` prefix and the `.ts`/`.js` extension automatically to resolve the compiled module. ```bash ./scripts/test.sh --run src/vs/editor/test/common/model.test.ts ``` Multiple files can be specified by repeating `--run`: ```bash ./scripts/test.sh --run src/vs/editor/test/common/model.test.ts --run src/vs/editor/test/common/range.test.ts ``` #### `--grep <pattern>` (aliases: `-g`, `-f`) - Filter tests by name Runs only tests whose full title matches the pattern (passed to Mocha's `--grep`). ```bash ./scripts/test.sh --grep "should split lines" ``` Combine with `--run` to filter tests within a specific file: ```bash ./scripts/test.sh --run src/vs/editor/test/common/model.test.ts --grep "should split lines" ``` #### `--runGlob <pattern>` (aliases: `--glob`, `--runGrep`) - Run tests matching a glob Runs all test files matching a glob pattern against the compiled output directory. Useful for running all tests under a feature area. ```bash ./scripts/test.sh --runGlob "**/editor/test/**/*.test.js" ``` Note: the glob runs against compiled `.js` files in the output directory, not source `.ts` files. #### `--coverage` - Generate a coverage report ```bash ./scripts/test.sh --run src/vs/editor/test/common/model.test.ts --coverage ``` #### `--timeout <ms>` - Set test timeout Override the default Mocha timeout for long-running tests. ```bash ./scripts/test.sh --run src/vs/editor/test/common/model.test.ts --timeout 10000 ``` ### Integration tests Integration tests (files ending in `.integrationTest.ts` or located in `extensions/`) are **not run** by `scripts/test.sh`. Use `scripts/test-integration.sh` (or `scripts/test-integration.bat`) instead. See the `integration-tests` skill for details. ### Compilation requirement Tests run against compiled JavaScript output. Ensure the `VS Code - Build` watch task is running or that compilation has completed before running tests. Test failures caused by stale output are a common pitfall.

Frequently asked questions

Unit Tests