import { test } from "bun:test"; import assert from "node:assert/strict"; import { BrowserSessionVideoSource, computeBrowserSessionCaptureDelayMs, shouldEmitBrowserSessionVideoFrame } from "./browserSessionVideoSource.ts";

test("computeBrowserSessionCaptureDelayMs prefers active cadence during the activity burst", () => { const activeDelay = computeBrowserSessionCaptureDelayMs(2_000, 1_500, { activeFramesPerSecond: 10, idleFramesPerSecond: 2, activityBurstMs: 1_000 }); const idleDelay = computeBrowserSessionCaptureDelayMs(4_000, 1_500, { activeFramesPerSecond: 10, idleFramesPerSecond: 2, activityBurstMs: 1_000 });

assert.equal(activeDelay, 100); assert.equal(idleDelay, 500); });

test("shouldEmitBrowserSessionVideoFrame emits initial, changed, and heartbeat frames", () => { const initial = shouldEmitBrowserSessionVideoFrame( { lastEmitAt: null, lastFrameSignature: null, lastFrameUrl: null, lastActivityAt: 0 }, { capturedAt: 100, signature: "a", currentUrl: "https://example.com" } ); assert.deepEqual(initial, { emit: true, changed: true, reason: "initial" });

const unchanged = shouldEmitBrowserSessionVideoFrame( { lastEmitAt: 100, lastFrameSignature: "a", lastFrameUrl: "https://example.com", lastActivityAt: 0 }, { capturedAt: 1_000, signature: "a", currentUrl: "https://example.com", heartbeatIntervalMs: 5_000 } ); assert.deepEqual(unchanged, { emit: false, changed: false, reason: "poll" });

const heartbeat = shouldEmitBrowserSessionVideoFrame( { lastEmitAt: 100, lastFrameSignature: "a", lastFrameUrl: "https://example.com", lastActivityAt: 0 }, { capturedAt: 5_200, signature: "a", currentUrl: "https://example.com", heartbeatIntervalMs: 5_000 } ); assert.deepEqual(heartbeat, { emit: true, changed: false, reason: "heartbeat" });

const changed = shouldEmitBrowserSessionVideoFrame( { lastEmitAt: 100, lastFrameSignature: "a", lastFrameUrl: "https://example.com", lastActivityAt: 4_700 }, { capturedAt: 5_000, signature: "b", currentUrl: "https://example.com", activityBurstMs: 500 } ); assert.deepEqual(changed, { emit: true, changed: true, reason: "activity" }); });

test("BrowserSessionVideoSource emits the initial frame and dedupes unchanged polls", async () => { let now = 1_000; let screenshotCalls = 0; let currentUrlCalls = 0; const frames: Array<{ reason: string; changed: boolean; currentUrl: string | null }> = [];

const source = new BrowserSessionVideoSource({ sessionKey: "browser-1", browserManager: { screenshot: async () => { screenshotCalls += 1; return screenshotCalls === 1 ? "data:image/png;base64,first" : "data:image/png;base64,first"; }, currentUrl: async () => { currentUrlCalls += 1; return "https://example.com"; } }, onFrame: (frame) => { frames.push({ reason: frame.reason, changed: frame.changed, currentUrl: frame.currentUrl }); }, now: () => now });

const initial = await source.pollOnce(); now = 2_000; const second = await source.pollOnce();

assert.ok(initial); assert.equal(second, null); assert.equal(screenshotCalls, 2); assert.equal(currentUrlCalls, 2); assert.deepEqual(frames, [ { reason: "initial", changed: true, currentUrl: "https://example.com" } ]); });

test("BrowserSessionVideoSource upgrades changed frames to activity after noteActivity", async () => { let now = 0; let screenshot = "data:image/png;base64,first"; const reasons: string[] = [];

const source = new BrowserSessionVideoSource({ sessionKey: "browser-1", browserManager: { screenshot: async () => screenshot, currentUrl: async () => "https://example.com" }, onFrame: (frame) => { reasons.push(frame.reason); }, now: () => now, activityBurstMs: 2_000 });

await source.pollOnce(); now = 5_000; source.noteActivity(); screenshot = "data:image/png;base64,second"; now = 5_100; await source.pollOnce();

assert.deepEqual(reasons, ["initial", "activity"]); });