Support options request for CORS pre-flight

src/server/server.test.ts

@@ -38,8 +38,8 @@ describe('server', () => {
       });
     });
 
-    describe('POST /hook/*', () => {
-      it('should return 404 when no client is connected', async () => {
+    describe('HTTP /hook/*', () => {
+      it('should return 404 when no client is connected (POST)', async () => {
         const response = await request(server)
           .post('/hook/test-path')
           .send({ test: 'data' })
@@ -48,6 +48,14 @@ describe('server', () => {
         expect(response.text).toContain('No matching client found');
       });
 
+      it('should return 404 when no client is connected (OPTIONS)', async () => {
+        const response = await request(server)
+          .options('/hook/test-path')
+          .expect(404);
+
+        expect(response.text).toContain('No matching client found');
+      });
+
       it('should relay request to connected client', (done) => {
         const ws = new WebSocket(`ws://localhost:${port}?clientId=test-client`);
 
@@ -94,6 +102,51 @@ describe('server', () => {
         });
       });
 
+      it('should relay OPTIONS request to connected client', (done) => {
+        const ws = new WebSocket(`ws://localhost:${port}?clientId=test-client`);
+
+        ws.on('message', (data) => {
+          const message = JSON.parse(data.toString());
+
+          if (message.kind === 'challenge') {
+            const challengeMessage = message as WebSocketChallengeMessage;
+            const hmac = createHmac('sha256', challengePassphrase)
+              .update(challengeMessage.nonce)
+              .digest('hex');
+
+            const response: WebSocketChallengeResponse = {
+              kind: 'challenge-response',
+              clientId: 'test-client',
+              hmac,
+            };
+            ws.send(JSON.stringify(response));
+          } else if (message.kind === 'challenge-result' && message.success) {
+            request(server)
+              .options('/hook/test-path')
+              .end(() => {});
+          } else if (message.kind === 'http') {
+            const httpMessage = message as WebSocketHTTPMessage;
+            expect(httpMessage.path).toBe('/test-path');
+            expect(httpMessage.method).toBe('OPTIONS');
+
+            const response: WebSocketHTTPResponse = {
+              kind: 'http',
+              clientId: 'test-client',
+              messageId: httpMessage.messageId,
+              headers: { 'Access-Control-Allow-Origin': '*', 'Access-Control-Allow-Methods': 'GET, POST, PUT, DELETE, OPTIONS' },
+              status: 200,
+              body: '',
+            };
+            ws.send(JSON.stringify(response));
+
+            setTimeout(() => {
+              ws.close();
+              done();
+            }, 100);
+          }
+        });
+      });
+
       it('should handle wildcard client', (done) => {
         const ws = new WebSocket(`ws://localhost:${port}?clientId=test-client`);
 

src/server/server.ts

@@ -234,7 +234,7 @@ export function createServer(logger: Logger, challengePassphrase: string): {
     });
   });
 
-  app.post('/hook/*', async (
+  const hookHandler = async (
     req: Request,
     res: Response,
   ) => {
@@ -315,7 +315,10 @@ export function createServer(logger: Logger, challengePassphrase: string): {
       logger.error(err, 'Error while receiving data');
       res.status(500).send('Error receiving data');
     });
-  });
+  };
+
+  app.post('/hook/*', hookHandler);
+  app.options('/hook/*', hookHandler);
 
   const CALLBACK_REGISTRATION_EXPIRATION_MS = 30 * 1000; // 30 seconds
   app.post('/callback/oneshot/register', express.json(), async (req: Request, res: Response) => {