Initial import from garrytan/gstack@026751e (main snapshot via local relay)

Source: https://github.com/garrytan/gstack/commit/026751e

browse/test/watch.test.ts

@@ -0,0 +1,129 @@
+/**
+ * Tests for watch mode state machine in BrowserManager.
+ *
+ * Pure unit tests — no browser needed. Just instantiate BrowserManager
+ * and test the watch state methods (startWatch, stopWatch, addWatchSnapshot,
+ * isWatching).
+ */
+
+import { describe, test, expect } from 'bun:test';
+import { BrowserManager } from '../src/browser-manager';
+
+describe('watch mode — state machine', () => {
+  test('isWatching returns false by default', () => {
+    const bm = new BrowserManager();
+    expect(bm.isWatching()).toBe(false);
+  });
+
+  test('startWatch sets isWatching to true', () => {
+    const bm = new BrowserManager();
+    bm.startWatch();
+    expect(bm.isWatching()).toBe(true);
+  });
+
+  test('stopWatch clears isWatching and returns snapshots', () => {
+    const bm = new BrowserManager();
+    bm.startWatch();
+    bm.addWatchSnapshot('snapshot-1');
+    bm.addWatchSnapshot('snapshot-2');
+
+    const result = bm.stopWatch();
+    expect(bm.isWatching()).toBe(false);
+    expect(result.snapshots).toEqual(['snapshot-1', 'snapshot-2']);
+    expect(result.snapshots.length).toBe(2);
+  });
+
+  test('stopWatch returns correct duration (approximately)', async () => {
+    const bm = new BrowserManager();
+    bm.startWatch();
+
+    // Wait ~50ms to get a measurable duration
+    await new Promise(resolve => setTimeout(resolve, 50));
+
+    const result = bm.stopWatch();
+    // Duration should be at least 40ms (allowing for timer imprecision)
+    expect(result.duration).toBeGreaterThanOrEqual(40);
+    // And less than 5 seconds (sanity check)
+    expect(result.duration).toBeLessThan(5000);
+  });
+
+  test('addWatchSnapshot stores snapshots', () => {
+    const bm = new BrowserManager();
+    bm.startWatch();
+
+    bm.addWatchSnapshot('page A content');
+    bm.addWatchSnapshot('page B content');
+    bm.addWatchSnapshot('page C content');
+
+    const result = bm.stopWatch();
+    expect(result.snapshots.length).toBe(3);
+    expect(result.snapshots[0]).toBe('page A content');
+    expect(result.snapshots[1]).toBe('page B content');
+    expect(result.snapshots[2]).toBe('page C content');
+  });
+
+  test('stopWatch resets snapshots for next cycle', () => {
+    const bm = new BrowserManager();
+
+    // First cycle
+    bm.startWatch();
+    bm.addWatchSnapshot('first-cycle-snapshot');
+    const result1 = bm.stopWatch();
+    expect(result1.snapshots.length).toBe(1);
+
+    // Second cycle — should start fresh
+    bm.startWatch();
+    const result2 = bm.stopWatch();
+    expect(result2.snapshots.length).toBe(0);
+  });
+
+  test('multiple start/stop cycles work correctly', () => {
+    const bm = new BrowserManager();
+
+    // Cycle 1
+    bm.startWatch();
+    expect(bm.isWatching()).toBe(true);
+    bm.addWatchSnapshot('snap-1');
+    const r1 = bm.stopWatch();
+    expect(bm.isWatching()).toBe(false);
+    expect(r1.snapshots).toEqual(['snap-1']);
+
+    // Cycle 2
+    bm.startWatch();
+    expect(bm.isWatching()).toBe(true);
+    bm.addWatchSnapshot('snap-2a');
+    bm.addWatchSnapshot('snap-2b');
+    const r2 = bm.stopWatch();
+    expect(bm.isWatching()).toBe(false);
+    expect(r2.snapshots).toEqual(['snap-2a', 'snap-2b']);
+
+    // Cycle 3 — no snapshots added
+    bm.startWatch();
+    expect(bm.isWatching()).toBe(true);
+    const r3 = bm.stopWatch();
+    expect(bm.isWatching()).toBe(false);
+    expect(r3.snapshots).toEqual([]);
+  });
+
+  test('stopWatch clears watchInterval if set', () => {
+    const bm = new BrowserManager();
+    bm.startWatch();
+
+    // Simulate an interval being set (as the server does)
+    bm.watchInterval = setInterval(() => {}, 100000);
+    expect(bm.watchInterval).not.toBeNull();
+
+    bm.stopWatch();
+    expect(bm.watchInterval).toBeNull();
+  });
+
+  test('stopWatch without startWatch returns empty results', () => {
+    const bm = new BrowserManager();
+
+    // Calling stopWatch without startWatch should not throw
+    const result = bm.stopWatch();
+    expect(result.snapshots).toEqual([]);
+    expect(result.duration).toBeLessThanOrEqual(Date.now()); // duration = now - 0
+    expect(bm.isWatching()).toBe(false);
+  });
+});