feat(api/private): add UsersController

The UsersController can be used to fetch information about users.

Signed-off-by: David Mehren <git@herrmehren.de>

test/private-api/users.e2e-spec.ts

@@ -0,0 +1,42 @@
+/*
+ * SPDX-FileCopyrightText: 2022 The HedgeDoc developers (see AUTHORS file)
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+import request from 'supertest';
+
+import { TestSetup, TestSetupBuilder } from '../test-setup';
+
+describe('Users', () => {
+  let testSetup: TestSetup;
+
+  beforeEach(async () => {
+    testSetup = await TestSetupBuilder.create().withUsers().build();
+    await testSetup.app.init();
+  });
+
+  afterEach(async () => {
+    await testSetup.app.close();
+  });
+
+  test('details for existing users can be retrieved', async () => {
+    let response = await request
+      .agent(testSetup.app.getHttpServer())
+      .get('/api/private/users/testuser1');
+    expect(response.status).toBe(200);
+    expect(response.body.username).toBe('testuser1');
+
+    response = await request
+      .agent(testSetup.app.getHttpServer())
+      .get('/api/private/users/testuser2');
+    expect(response.status).toBe(200);
+    expect(response.body.username).toBe('testuser2');
+  });
+
+  test('details for non-existing users cannot be retrieved', async () => {
+    const response = await request
+      .agent(testSetup.app.getHttpServer())
+      .get('/api/private/users/i_dont_exist');
+    expect(response.status).toBe(404);
+  });
+});