| name | verify |
| description | Verifies nontrivial MixJam renderer changes against the built Chromium surface using pixels, computed styles, and canvas sampling. |
Verify MixJam Renderer
Verify renderer changes against the production bundle. Unit tests stub canvas,
so theme, CSS, drawing, and tracker behavior need evidence from real Chromium.
Build and Drive
- Remove
ELECTRON_RUN_AS_NODE from the command environment when launching
Electron; the Chromium-only path is unaffected.
- Run
npm run build and require a clean exit.
- Serve
out/renderer with node scripts/serve-static.mjs <port> in a
background process.
- Create
tmp/verify-<slug>.mjs inside the repository so Playwright resolves
the local node_modules.
- Drive only the changed states and write screenshots plus a short evidence
report under
tmp/verify-<slug>/.
- Stop the static server after the assertions finish.
Seed Without Real Folders
Inject a mock window.backendAPI with page.addInitScript before page.goto.
Copy its shape from tests/e2e/fixtures.ts and compare it with
src/shared/backend-api.ts. Assert the feature fed by each mocked method; app
boot alone does not prove the mock is complete.
Drive the Tracker
- Switch theme with
page.locator('.theme-selector').selectOption('<key>').
- Place a clip by dispatching
DragEvent('drop') on
.tracker-lane-canvas. Attach a DataTransfer whose
application/mixjam-sample value is serialized FooterSampleDetail.
- Use a duration that makes the clip wide enough for stable pixel sampling.
- Start playback before asserting the playhead because it renders only while
playing.
Assert the Surface
- Read theme tokens through
getComputedStyle(document.documentElement).
- Sample canvas pixels through
getImageData; ignore pixels with alpha below
250 before comparing exact lowercased theme colors.
- Compare resolved DOM colors as computed
rgb(...), not unresolved CSS
variables.
- Assert behavior or computed values in addition to screenshots.
- Account for the observed
devicePixelRatio when sampling coordinates.
Completion Criterion
Verification is complete when the production build passes, the relevant user
states are driven in Chromium, every changed visual or interaction contract has
an objective assertion, screenshots and an evidence report exist under the
run-specific tmp/verify-<slug>/ directory, and the background server is
stopped. Report exact failed assertions without claiming verification passed.
