Worker startup

Find it in the repository

Collector source

core/signals/timing/worker-startup.ts

Export

measurementModule · Signal object

Field definitions

core/definitions/timing/worker-startup.ts

Capture membership

Product capture · common/capture/product.ts

Page registration

app/signals/registry.ts

Field projection

core/results/measurement.ts

Execution contract

Signal

timing.worker-startup

Collector

timing.worker-startup

API / surface

core/signals/timing/worker-startup.ts

Timeout

3000 ms

Companion signals

None

Fixture inputs

Declared requests (listed below)

[
  {
    "key": "timing.worker-startup.workers",
    "inputs": {
      "startup-0": {
        "index": 0,
        "sourceBytes": 101,
        "sameSource": true,
        "sameUrl": true
      },
      "startup-1": {
        "index": 1,
        "sourceBytes": 101,
        "sameSource": true,
        "sameUrl": true
      },
      "startup-2": {
        "index": 2,
        "sourceBytes": 101,
        "sameSource": true,
        "sameUrl": true
      },
      "startup-3": {
        "index": 3,
        "sourceBytes": 101,
        "sameSource": true,
        "sameUrl": true
      },
      "startup-4": {
        "index": 4,
        "sourceBytes": 101,
        "sameSource": true,
        "sameUrl": true
      },
      "startup-5": {
        "index": 5,
        "sourceBytes": 101,
        "sameSource": true,
        "sameUrl": true
      },
      "startup-6": {
        "index": 6,
        "sourceBytes": 101,
        "sameSource": true,
        "sameUrl": true
      },
      "startup-7": {
        "index": 7,
        "sourceBytes": 101,
        "sameSource": true,
        "sameUrl": true
      }
    },
    "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/timing.worker-startup. 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/timing/worker-startup"

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