Console formatter callbacks

Find it in the repository

Collector source

core/signals/javascript/preview.ts

Export

measurementModule · Signal object

Field definitions

core/definitions/javascript/preview.ts

Capture membership

Product capture · common/capture/product.ts

Page registration

app/signals/registry.ts

Field projection

core/results/measurement.ts

Execution contract

Signal

javascript.preview

Collector

javascript.preview

API / surface

core/signals/javascript/preview.ts

Timeout

3000 ms

Companion signals

None

Fixture inputs

Declared requests (listed below)

[
  {
    "key": "javascript.preview.responses",
    "inputs": {
      "observation": {
        "mode": "current-browser",
        "controller": "none",
        "server": null
      }
    },
    "controls": {}
  }
]

One collector runs per invocation. Results and JSON select this signal’s fields; any companions execute in the same collector.

Generated source manifest lists runtime files, fixture URLs and content digests for this build. The Source tab provides a copyable console sample.

Run and edit locally

From the repository root, start the Astro app, then open /signals/javascript.preview. Edit the collector source and reload the page to load its new build.

pnpm run dev:web

In a browser module served by this repository’s Vite graph:

import { createCollector } from "/core/collect"
import { measurementModule } from "/core/signals/javascript/preview"

const signal = measurementModule
const collector = createCollector()
const suite = { signals: [signal] }
const result = await collector.collect(suite)

Reuse the collector owner for repeated calls so collection can enforce cleanup. This returns the collector’s raw result; app/signals/projection.ts selects the retained fields shown on this page.

rg -n 'measurementModule' core app tests
pnpm run check
pnpm run test tests/unit/app/focused-projection.test.ts