test: observe aircraft arrival before idle refresh

src/tooling/trackArrivalObservation.test.mjs

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+import test from 'node:test';
+import assert from 'node:assert/strict';
+import {
+  ARRIVAL_OBSERVATION_MS,
+  arrivalRotationPassed,
+  observeArrivalRotation,
+} from './trackArrivalObservation.mjs';
+
+function fixture() {
+  let time = 0;
+  let state = { shown: true, rotationError: 0 };
+  const listeners = new Set();
+  const timers = new Map();
+  let renders = 0;
+  let moveEnds = 0;
+  const observation = observeArrivalRotation({
+    scene: {
+      postRender: {
+        addEventListener(listener) {
+          listeners.add(listener);
+          return () => listeners.delete(listener);
+        },
+      },
+      requestRender() {
+        renders++;
+      },
+    },
+    startMoveEnd() {
+      moveEnds++;
+      state.rotationError = 1.5;
+    },
+    startReveal() {
+      state = { shown: false, rotationError: 1.5 };
+    },
+    read: () => ({ ...state }),
+    now: () => time,
+    setTimer(callback, delay) {
+      const handle = {};
+      timers.set(handle, { callback, at: time + delay });
+      return handle;
+    },
+    clearTimer(handle) {
+      timers.delete(handle);
+    },
+  });
+  return {
+    observation,
+    frame(at, nextState) {
+      time = at;
+      state = { ...state, ...nextState };
+      for (const listener of [...listeners]) listener();
+    },
+    expire(at) {
+      time = at;
+      for (const timer of [...timers.values()])
+        if (timer.at <= at) timer.callback();
+    },
+    get resources() {
+      return {
+        listeners: listeners.size,
+        timers: timers.size,
+        renders,
+        moveEnds,
+      };
+    },
+  };
+}
+
+test('80 ms fleet scheduling passes after more than four fast rendered frames', async () => {
+  const f = fixture();
+  f.frame(8, { shown: true, rotationError: 0 });
+  // The forced fleet tick was at 8 ms. A 125 FPS renderer can complete nine
+  // more frames before the next 80 ms fleet interval becomes eligible.
+  for (let at = 16; at < 88; at += 8) f.frame(at);
+  f.frame(88, { shown: true, rotationError: 0 });
+  const result = await f.observation;
+  assert.equal(result.flipFrame, 10);
+  assert.equal(result.moveEndMs, 8);
+  assert.equal(result.revealMs, 80);
+  assert.equal(result.elapsedMs, 88);
+  assert.equal(arrivalRotationPassed(result), true);
+  assert.equal(f.resources.listeners, 0);
+  assert.equal(f.resources.timers, 0);
+  assert.equal(f.resources.moveEnds, 1);
+});
+
+test('a wrong first visible angle fails even if the next frame corrects it', async () => {
+  const f = fixture();
+  f.frame(8, { shown: true, rotationError: 0 });
+  f.frame(88, { shown: true, rotationError: 1.5 });
+  f.frame(96, { shown: true, rotationError: 0 });
+  const result = await f.observation;
+  assert.equal(result.dReveal, 1.5);
+  assert.equal(result.flipFrame, 1);
+  assert.equal(result.elapsedMs, 88);
+  assert.equal(arrivalRotationPassed(result), false);
+});
+
+test('a wrong first moveEnd angle is retained rather than repaired by reveal', async () => {
+  const f = fixture();
+  f.frame(8, { shown: true, rotationError: 1.5 });
+  f.frame(88, { shown: true, rotationError: 0 });
+  const result = await f.observation;
+  assert.equal(result.dMoveEnd, 1.5);
+  assert.equal(arrivalRotationPassed(result), false);
+});
+
+test('no reveal fails at a deadline before the one-second idle catch-up', async () => {
+  const f = fixture();
+  assert.equal(ARRIVAL_OBSERVATION_MS, 500);
+  f.frame(8, { shown: true, rotationError: 0 });
+  f.frame(480);
+  f.expire(500);
+  const result = await f.observation;
+  assert.match(result.error, /reveal.*500 ms/);
+  assert.equal(arrivalRotationPassed(result), false);
+  assert.equal(f.resources.listeners, 0);
+  assert.equal(f.resources.timers, 0);
+  f.frame(1000, { shown: true, rotationError: 0 });
+  assert.equal(result.flipFrame, -1);
+});
+
+test('a late visible frame fails even if the timeout callback is delayed', async () => {
+  const f = fixture();
+  f.frame(8, { shown: true, rotationError: 0 });
+  f.frame(501, { shown: true, rotationError: 0 });
+  const result = await f.observation;
+  assert.match(result.error, /reveal.*500 ms/);
+  assert.equal(result.elapsedMs, 501);
+  assert.equal(arrivalRotationPassed(result), false);
+});
+
+test('the deadline includes moveEnd setup rather than restarting when hidden', async () => {
+  const f = fixture();
+  f.frame(400, { shown: true, rotationError: 0 });
+  f.frame(600, { shown: true, rotationError: 0 });
+  const result = await f.observation;
+  assert.equal(result.moveEndMs, 400);
+  assert.equal(result.elapsedMs, 600);
+  assert.equal(arrivalRotationPassed(result), false);
+});
+
+test('missing moveEnd frames fail without waiting for a render callback', async () => {
+  const f = fixture();
+  f.expire(500);
+  const result = await f.observation;
+  assert.match(result.error, /moveEnd.*500 ms/);
+  assert.equal(arrivalRotationPassed(result), false);
+  assert.equal(f.resources.listeners, 0);
+  assert.equal(f.resources.timers, 0);
+});