Context

• Project files: !find . -maxdepth 1 ( -name 'pyproject.toml' -o -name 'package.json' -o -name 'Cargo.toml' -o -name 'go.mod' )

• Playwright config: !find . -maxdepth 1 -name 'playwright.config.*'

• Vitest config: !find . -maxdepth 1 ( -name 'vitest.config.' -o -name 'vite.config.' )

• Jest config: !find . -maxdepth 1 -name 'jest.config.*'

• Pytest config: !find . -maxdepth 1 ( -name pyproject.toml -o -name setup.cfg ) -exec grep -l 'pytest' {} +

• Package.json exists: !find . -maxdepth 1 -name 'package.json' -type f

Parameters

• $1 (required): Test file path or pattern (e.g., login.spec.ts , tests/e2e/auth.spec.ts )

• --serial : Force sequential execution with single worker (useful for WebGL, database tests)

• --debug : Run in debug/headed mode for visual debugging

Your task

Run a single test file in fail-fast mode for rapid development iteration. Stop immediately on first failure to minimize feedback time.

1. Detect test framework and construct command

Playwright (if playwright.config.* exists):

Standard fail-fast

bunx playwright test "$FILE" --max-failures=1 --reporter=line

With --serial (WebGL, shared state)

bunx playwright test "$FILE" --max-failures=1 --workers=1 --reporter=line

With --debug

bunx playwright test "$FILE" --max-failures=1 --headed --debug

Vitest (if vitest.config.* or vite.config.* exists):

Standard fail-fast

bunx vitest run "$FILE" --bail=1 --reporter=dot

With --serial

bunx vitest run "$FILE" --bail=1 --pool=forks --poolOptions.threads.singleThread --reporter=dot

With --debug

bunx vitest run "$FILE" --bail=1 --inspect-brk

Jest (if jest.config.* exists):

Standard fail-fast

bunx jest "$FILE" --bail --silent

With --serial

bunx jest "$FILE" --bail --runInBand --silent

With --debug

bunx jest "$FILE" --bail --runInBand

pytest (Python projects):

Standard fail-fast

python -m pytest "$FILE" -x -v --tb=short

With --serial (already serial by default)

python -m pytest "$FILE" -x -v --tb=short

With --debug

python -m pytest "$FILE" -x -v --tb=long -s

Cargo test (Rust projects):

Standard fail-fast

cargo test --test "$FILE" -- --test-threads=1

With --debug

cargo test --test "$FILE" -- --test-threads=1 --nocapture

Go test:

Standard fail-fast

go test -v -failfast "$FILE"

With --debug

go test -v -failfast "$FILE" -count=1

2. Execute the test

Run the constructed command. Capture and display output.

3. Analyze results

If the test passes:

Duration: Xs

Ready for next iteration or file.

If the test fails:

Duration: Xs

First failure: Test: [test name] Error: [brief error message] Location: [file:line]

Quick actions:

• Fix the issue and re-run: /test:focus [same file]
• Debug visually: /test:focus file --debug
• See full output: /test:run file

4. Provide rerun command

Always show the exact command to rerun:

Rerun: /test:focus $FILE

Time savings context

Focused testing dramatically reduces feedback time:

Approach Typical Duration Use Case

/test:focus

2-30 seconds Iterating on single file

/test:quick

30 seconds Unit tests after changes

/test:full

5-30 minutes Before commit/PR

Agentic optimizations

Context Flags

Playwright fast --max-failures=1 --reporter=line

Playwright WebGL --max-failures=1 --workers=1 --reporter=line

Vitest fast --bail=1 --reporter=dot

Jest fast --bail --silent

pytest fast -x -v --tb=short

Error handling

• If file not found: List similar test files with glob and suggest corrections

• If framework not detected: Show available package.json scripts containing "test"

• If test times out: Suggest --serial flag or increasing timeout