Vitest Runner

Vitest runner

Targeted runs

vitest run --reporter=basic path/to/file.test.ts

Always prefer this over vitest (watch mode) — agent sessions should not leave a long-running process behind. If you do want watch mode for a human session, vitest watch is explicit and easier to spot in ps.

Multiple files

vitest run --reporter=basic 'src/**/*.test.ts'

Quote the glob — your shell may expand it differently than vitest expects.

Filtering by test name

vitest run --reporter=basic -t "describe-name pattern"

When tests fail

1. Read the first failure carefully. vitest reports failures in source order, and one root cause often cascades into several apparent failures further down. Fixing the first usually clears the rest.
2. Re-run the failing file with --reporter=verbose for stack details:

   vitest run --reporter=verbose path/to/file.test.ts
   

3. Don't stub or mock to make a test pass without understanding the underlying break. If the production code is wrong, fix the production code; if the test is wrong, justify the change in the commit message.

Coverage

Only when explicitly requested:

vitest run --coverage --reporter=basic

--coverage slows the run substantially and writes a coverage/ directory. Don't enable it by default.

Snapshot tests

vitest run -u updates snapshots. Only do this when the snapshot output is reviewed and intentional — never as a way to make a snapshot test pass.