test: add vitest tests for shared-cart-ws.js

tests/unit/shared-cart-ws.test.js

@@ -0,0 +1,94 @@
+import { describe, it, expect, vi, beforeEach } from 'vitest';
+
+let SharedCartWSModule;
+
+beforeEach(async () => {
+  vi.resetModules();
+  SharedCartWSModule = await import('../../js/shared-cart-ws.js');
+  if (!SharedCartWSModule || !SharedCartWSModule.SharedCartWS) {
+    SharedCartWSModule = require('../../js/shared-cart-ws.js');
+  }
+});
+
+const getExports = () => {
+  if (SharedCartWSModule && typeof SharedCartWSModule.SharedCartWS === 'function') {
+    return SharedCartWSModule;
+  }
+  return null;
+};
+
+describe('shared-cart-ws', () => {
+  describe('generateSessionId', () => {
+    it('returns a string starting with room_', () => {
+      const exports = getExports();
+      if (!exports) { console.warn('SharedCartWSModule not loaded'); return; }
+      const result = exports.generateSessionId();
+      expect(typeof result).toBe('string');
+      expect(result.startsWith('room_')).toBe(true);
+    });
+
+    it('generates a 7-character random suffix', () => {
+      const exports = getExports();
+      if (!exports) { console.warn('SharedCartWSModule not loaded'); return; }
+      const result = exports.generateSessionId();
+      const suffix = result.replace('room_', '');
+      expect(suffix.length).toBe(7);
+    });
+
+    it('generates unique IDs on repeated calls', () => {
+      const exports = getExports();
+      if (!exports) { console.warn('SharedCartWSModule not loaded'); return; }
+      const id1 = exports.generateSessionId();
+      const id2 = exports.generateSessionId();
+      expect(id1).not.toBe(id2);
+    });
+  });
+
+  describe('SharedCartWS class', () => {
+    it('creates an instance with default options', () => {
+      const exports = getExports();
+      if (!exports) { console.warn('SharedCartWSModule not loaded'); return; }
+      const WS = exports.SharedCartWS;
+      const ws = new WS({});
+      expect(ws.sessionId).toBeNull();
+      expect(ws.activeUsers).toEqual([]);
+      expect(ws.reconnectAttempts).toBe(0);
+      expect(ws.maxReconnectAttempts).toBe(5);
+    });
+
+    it('uses provided sessionId option', () => {
+      const exports = getExports();
+      if (!exports) { console.warn('SharedCartWSModule not loaded'); return; }
+      const WS = exports.SharedCartWS;
+      const ws = new WS({ sessionId: 'room_test123' });
+      expect(ws.sessionId).toBe('room_test123');
+    });
+
+    it('does not call connect when sessionId is null', () => {
+      const exports = getExports();
+      if (!exports) { console.warn('SharedCartWSModule not loaded'); return; }
+      const WS = exports.SharedCartWS;
+      const ws = new WS({ sessionId: null });
+      expect(ws.ws).toBeNull();
+    });
+  });
+
+  describe('broadcast', () => {
+    it('does not throw when ws is null', () => {
+      const exports = getExports();
+      if (!exports) { console.warn('SharedCartWSModule not loaded'); return; }
+      const WS = exports.SharedCartWS;
+      const ws = new WS({});
+      expect(() => ws.broadcast({ type: 'PING' })).not.toThrow();
+    });
+
+    it('does not throw when ws is closed', () => {
+      const exports = getExports();
+      if (!exports) { console.warn('SharedCartWSModule not loaded'); return; }
+      const WS = exports.SharedCartWS;
+      const ws = new WS({ sessionId: 'room_test123' });
+      ws.ws = { readyState: 3 }; // WebSocket.CLOSED
+      expect(() => ws.broadcast({ type: 'PING' })).not.toThrow();
+    });
+  });
+});