feat: Advertise WebSocket via Updates-Via header.

test/unit/ldp/http/metadata/WebSocketMetadataWriter.test.ts

@@ -0,0 +1,37 @@
+import { createResponse } from 'node-mocks-http';
+import { WebSocketMetadataWriter } from '../../../../../src/ldp/http/metadata/WebSocketMetadataWriter';
+
+describe('A WebSocketMetadataWriter', (): void => {
+  it('writes a default HTTP WebSocket.', async(): Promise<void> => {
+    const writer = new WebSocketMetadataWriter({});
+    const response = createResponse();
+    await writer.handle({ response } as any);
+    expect(response.getHeaders()).toEqual({ 'updates-via': 'ws://localhost' });
+  });
+
+  it('writes an HTTP WebSocket with port 80.', async(): Promise<void> => {
+    const writer = new WebSocketMetadataWriter({ hostname: 'test.example', port: 80, protocol: 'http' });
+    const response = createResponse();
+    await writer.handle({ response } as any);
+    expect(response.getHeaders()).toEqual({ 'updates-via': 'ws://test.example' });
+  });
+
+  it('writes an HTTP WebSocket with port 3000.', async(): Promise<void> => {
+    const writer = new WebSocketMetadataWriter({ hostname: 'test.example', port: 3000, protocol: 'http' });
+    const response = createResponse();
+    await writer.handle({ response } as any);
+    expect(response.getHeaders()).toEqual({ 'updates-via': 'ws://test.example:3000' });
+  });
+
+  it('writes an HTTPS WebSocket with port 443.', async(): Promise<void> => {
+    const writer = new WebSocketMetadataWriter({ hostname: 'test.example', port: 443, protocol: 'https' });
+    const response = createResponse();
+    await writer.handle({ response } as any);
+    expect(response.getHeaders()).toEqual({ 'updates-via': 'wss://test.example' });
+  });
+
+  it('rejects an invalid hostname.', (): void => {
+    expect((): any => new WebSocketMetadataWriter({ hostname: 'test.example/invalid' }))
+      .toThrow('Invalid hostname: test.example/invalid');
+  });
+});