add replay session

tests/run.js

@@ -12,3 +12,5 @@ import "./csv_import.test.js";
 import "./server_persistence.integration.test.js";
 
 import "./training_views.test.js";
+
+import "./session_replay.test.js";

tests/session_replay.test.js

@@ -0,0 +1,64 @@
+import test from "node:test";
+import assert from "node:assert/strict";
+import {
+  advanceSessionReplay,
+  buildSessionReplaySnapshot,
+  createSessionReplayRuntime,
+  loadSessionReplay,
+  pauseSessionReplay,
+  playSessionReplay,
+  resetSessionReplay,
+  setSessionReplaySpeed,
+} from "../src/session_replay.js";
+
+const passings = [
+  { timestamp: 1000, competitorKey: "a", driverName: "Alpha", transponder: "1", lapMs: 0, validLap: true },
+  { timestamp: 1200, competitorKey: "b", driverName: "Beta", transponder: "2", lapMs: 0, validLap: true },
+  { timestamp: 11000, competitorKey: "a", driverName: "Alpha", transponder: "1", lapMs: 10000, validLap: true },
+  { timestamp: 11700, competitorKey: "b", driverName: "Beta", transponder: "2", lapMs: 10500, validLap: true },
+  { timestamp: 20500, competitorKey: "a", driverName: "Alpha", transponder: "1", lapMs: 9500, validLap: true },
+  { timestamp: 21000, competitorKey: "b", driverName: "Beta", transponder: "2", lapMs: 9300, validLap: false },
+];
+
+test("session replay builds an isolated race leaderboard at the selected time", () => {
+  const runtime = createSessionReplayRuntime();
+  loadSessionReplay(runtime, { id: "race_1", name: "A final", type: "final" }, { passings: [...passings].reverse() });
+  runtime.elapsedMs = 15000;
+  const snapshot = buildSessionReplaySnapshot(runtime);
+
+  assert.equal(snapshot.visiblePassings.length, 4);
+  assert.deepEqual(snapshot.leaderboard.map((row) => [row.driverName, row.laps]), [["Alpha", 1], ["Beta", 1]]);
+  assert.equal(snapshot.latestPassing.driverName, "Beta");
+  assert.equal(runtime.passings.length, 6);
+});
+
+test("practice replay ranks best valid lap and ignores invalid laps", () => {
+  const runtime = createSessionReplayRuntime();
+  loadSessionReplay(runtime, { id: "practice_1", name: "Practice", type: "practice" }, { passings });
+  runtime.elapsedMs = runtime.durationMs;
+  const snapshot = buildSessionReplaySnapshot(runtime);
+
+  assert.equal(snapshot.leaderboard[0].driverName, "Alpha");
+  assert.equal(snapshot.leaderboard[0].bestLapMs, 9500);
+  assert.equal(snapshot.leaderboard[1].bestLapMs, 10500);
+  assert.equal(snapshot.leaderboard[1].laps, 1);
+});
+
+test("session replay play, speed, pause, finish, and reset are deterministic", () => {
+  const runtime = createSessionReplayRuntime();
+  loadSessionReplay(runtime, { id: "race_1", type: "final" }, { passings });
+  assert.equal(playSessionReplay(runtime, 100), true);
+  setSessionReplaySpeed(runtime, 5, 1100);
+  assert.equal(runtime.elapsedMs, 1000);
+  advanceSessionReplay(runtime, 2100);
+  assert.equal(runtime.elapsedMs, 6000);
+  assert.equal(pauseSessionReplay(runtime, 2200), true);
+  assert.equal(runtime.status, "paused");
+  playSessionReplay(runtime, 3000);
+  advanceSessionReplay(runtime, 10000);
+  assert.equal(runtime.status, "finished");
+  assert.equal(runtime.elapsedMs, runtime.durationMs);
+  resetSessionReplay(runtime);
+  assert.equal(runtime.status, "paused");
+  assert.equal(runtime.elapsedMs, 0);
+});