Testing and Baselines

StreamMDX includes local-only regression baselines that lock in HTML output and critical CSS styles while streaming.

What is covered

• HTML snapshots across streaming scenarios (slow, typical, fast, chunky, split boundaries).
• Computed styles for typography, tables, lists, blockquotes, footnotes, and preview/code adjacency.

Update baselines (local)

npm run test:regression:html:update
npm run test:regression:styles:update

Validate (no changes expected)

npm run test:regression:html
npm run test:regression:styles

Artifacts for failures are written to tests/regression/artifacts/ and are ignored by git.

Performance baseline (local)

The demo page exposes an automation API for perf capture. Run the dev server with the API enabled:

NEXT_PUBLIC_STREAMING_DEMO_API=true npm run docs:dev

Then capture a baseline:

npm run perf:demo -- --rate 12000 --tick 5 --runs 1

The script writes JSON output under tmp/perf-baseline/.

Notes

• Release/publish gates run the regression checks on the docs app.
• If you add fixtures, update tests/regression/fixtures/index.ts and regenerate snapshots.