feat: Add support for the Notification specification

test/unit/server/notifications/ComposedNotificationHandler.test.ts

@@ -0,0 +1,82 @@
+import { BasicRepresentation } from '../../../../src/http/representation/BasicRepresentation';
+import type { ResourceIdentifier } from '../../../../src/http/representation/ResourceIdentifier';
+import { ComposedNotificationHandler } from '../../../../src/server/notifications/ComposedNotificationHandler';
+import type { NotificationGenerator } from '../../../../src/server/notifications/generate/NotificationGenerator';
+import type { Notification } from '../../../../src/server/notifications/Notification';
+import type { NotificationEmitter } from '../../../../src/server/notifications/NotificationEmitter';
+import type { NotificationSerializer } from '../../../../src/server/notifications/serialize/NotificationSerializer';
+import type { SubscriptionInfo } from '../../../../src/server/notifications/SubscriptionStorage';
+
+describe('A ComposedNotificationHandler', (): void => {
+  const topic: ResourceIdentifier = { path: 'http://example.com/foo' };
+  const notification: Notification = {
+    '@context': [
+      'https://www.w3.org/ns/activitystreams',
+      'https://www.w3.org/ns/solid/notification/v1',
+    ],
+    id: `urn:123:http://example.com/foo`,
+    type: [ 'Update' ],
+    object: {
+      id: 'http://example.com/foo',
+      type: [],
+    },
+    published: '123',
+    state: '123',
+  };
+  let info: SubscriptionInfo;
+  const representation = new BasicRepresentation();
+  let generator: jest.Mocked<NotificationGenerator>;
+  let serializer: jest.Mocked<NotificationSerializer>;
+  let emitter: jest.Mocked<NotificationEmitter>;
+  let handler: ComposedNotificationHandler;
+
+  beforeEach(async(): Promise<void> => {
+    info = {
+      id: 'id',
+      topic: 'http://example.com/foo',
+      type: 'type',
+      features: {},
+      lastEmit: 0,
+    };
+
+    generator = {
+      canHandle: jest.fn(),
+      handle: jest.fn().mockResolvedValue(notification),
+    } as any;
+
+    serializer = {
+      handleSafe: jest.fn().mockResolvedValue(representation),
+    } as any;
+
+    emitter = {
+      handleSafe: jest.fn(),
+    } as any;
+
+    handler = new ComposedNotificationHandler({ generator, serializer, emitter });
+  });
+
+  it('can only handle input supported by the generator.', async(): Promise<void> => {
+    await expect(handler.canHandle({ info, topic })).resolves.toBeUndefined();
+    generator.canHandle.mockRejectedValue(new Error('bad input'));
+    await expect(handler.canHandle({ info, topic })).rejects.toThrow('bad input');
+  });
+
+  it('calls the three wrapped classes in order.', async(): Promise<void> => {
+    await expect(handler.handle({ info, topic })).resolves.toBeUndefined();
+    expect(generator.handle).toHaveBeenCalledTimes(1);
+    expect(generator.handle).toHaveBeenLastCalledWith({ info, topic });
+    expect(serializer.handleSafe).toHaveBeenCalledTimes(1);
+    expect(serializer.handleSafe).toHaveBeenLastCalledWith({ info, notification });
+    expect(emitter.handleSafe).toHaveBeenCalledTimes(1);
+    expect(emitter.handleSafe).toHaveBeenLastCalledWith({ info, representation });
+  });
+
+  it('does not emit the notification if its state matches the info state.', async(): Promise<void> => {
+    info.state = notification.state;
+    await expect(handler.handle({ info, topic })).resolves.toBeUndefined();
+    expect(generator.handle).toHaveBeenCalledTimes(1);
+    expect(generator.handle).toHaveBeenLastCalledWith({ info, topic });
+    expect(serializer.handleSafe).toHaveBeenCalledTimes(0);
+    expect(emitter.handleSafe).toHaveBeenCalledTimes(0);
+  });
+});