8. Generator logic

You will create a second pump during execution. Its collection membership will trigger the existing work definition.

Create the Generator source

Create generator.workspec.js:

// @ts-check
/// <reference types="workspec/workspec-generator" />

WorkSpec.onUpdate(({ time, create }) => {
  if (time !== 483) {
    return;
  }

  create({
    id: "pump_b",
    type: "product",
    name: "Pump B",
    location: "intake",
    properties: { quantity: 1, state: "awaiting_inspection" }
  });
});

The runtime expresses 08:03 as elapsed minute 483. Generator callbacks receive elapsed minutes in time.

Validate the generated run

Run project validation through 08:05:

npx workspec validate dynamic-start.workspec.json \
  --generator generator.workspec.js \
  --time 08:05

Expected final line:

✓ No problems found

Inspect the indirect result

Run a snapshot with the same horizon:

npx workspec snapshot dynamic-start.workspec.json \
  --generator generator.workspec.js \
  --time 08:05 \
  --json

The snapshot contains pump_a and pump_b. It also contains one inspect_arrival task instance for each pump.

The runtime follows this path:

1. The Generator creates pump_b as a world object.
2. pump_b matches the declared waiting_pumps collection.
3. The runtime evaluates the inspect_arrival work definition.
4. The runtime creates a task instance correlated with pump_b.

Keep the run deterministic

Use the Generator context's random() function when behavior needs random values. Do not use Math.random().

Supply --seed to reproduce seeded Generator behavior. The default seed is 1.

Read Generator and dynamic work for the ownership boundary. Read Generator execution order for same-time behavior.

Next step

Complete the capstone project with all four project files.