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TDD Mode

TDD mode is for local iteration. It compares screenshots against local baselines in .vizzly/.

Use it when you want fast feedback without uploading every run.

Two ways to use it

vizzly tdd start

Start a background server and keep it running while your tests run in watch mode.

Terminal window
vizzly tdd start --open
npm test -- --watch

Good for active UI work. The dashboard updates as screenshots arrive.

TDD starts on port 47392 by default. If that port is busy, Vizzly auto-allocates another free port and prints the dashboard URL. Use the exact port from that output when you want to check or stop a specific server.

Useful options:

  • --open
  • --port
  • --threshold
  • --baseline-build
  • --baseline-comparison
  • --fail-on-diff

Stop it with:

Terminal window
vizzly tdd stop

You can also check the current server:

Terminal window
vizzly tdd status
vizzly tdd status --port 47393
vizzly tdd list

Stop accepts the same explicit port:

Terminal window
vizzly tdd stop --port 47393

status and stop target Vizzly’s registered daemon for the current workspace or the port you pass. They don’t blindly kill whatever process happens to be listening on that port.

vizzly tdd run

Run tests once, write local review data, and clean up.

Terminal window
vizzly tdd run "npm test" --no-open

The run records .vizzly/report-data.json and prints a local context command for follow-up inspection. If screenshots were captured, Vizzly also writes a static report at .vizzly/report/index.html and copies report images under .vizzly/report/images/....

Omit --no-open when you want Vizzly to open the static report automatically.

Useful options:

  • --no-open
  • --set-baseline
  • --baseline-build
  • --baseline-comparison
  • --threshold
  • --fail-on-diff

What gets stored locally

TDD mode writes local artifacts under .vizzly/, including baselines, current screenshots, diffs, and static reports.

Add .vizzly/ to .gitignore.

When to use cloud-backed baselines

--baseline-build and --baseline-comparison let you pull baselines from Vizzly Cloud. Those options need authentication.

If you do not pass them, TDD mode stays local.

Next steps