Add servicesManager test and registerServices method

platform/core/src/services/ServicesManager.js

@@ -1,9 +1,49 @@
+import log from './../log.js';
+
 export default class ServicesManager {
   constructor() {
     this.services = {};
+    this.registeredServiceNames = [];
   }
 
-  register(service) {
+  /**
+   *
+   * @param {Object} service
+   */
+  registerService(service) {
+    if (!service) {
+      log.warn(
+        'Attempting to register a null/undefined service. Exiting early.'
+      );
+      return;
+    }
+
+    let serviceName = service.name;
+
+    if (!serviceName) {
+      log.warn(`Service name not set. Exiting early.`);
+      return;
+    }
+
+    if (this.registeredServiceNames.includes(serviceName)) {
+      log.warn(
+        `Extension name ${serviceName} has already been registered. Exiting before duplicating services.`
+      );
+      return;
+    }
+
     this.services[service.name] = service;
+
+    // Track service registration
+    this.registeredServiceNames.push(serviceName);
+  }
+
+  /**
+   * An array of services.
+   *
+   * @param {Object[]} services - Array of services
+   */
+  registerServices(services) {
+    services.forEach(service => this.registerService(service));
   }
 }

platform/core/src/services/ServicesManager.test.js

@@ -0,0 +1,70 @@
+import ServicesManager from './ServicesManager.js';
+import log from '../log.js';
+
+jest.mock('./../log.js');
+
+describe('ServicesManager.js', () => {
+  let servicesManager;
+
+  beforeEach(() => {
+    servicesManager = new ServicesManager();
+    log.warn.mockClear();
+    jest.clearAllMocks();
+  });
+
+  describe('registerServices()', () => {
+    it('calls registerService() for each service', () => {
+      servicesManager.registerService = jest.fn();
+
+      const fakeServices = [
+        { name: 'UINotificationTestService', hide: jest.fn() },
+        { name: 'UIModalTestService', hide: jest.fn() },
+      ];
+
+      servicesManager.registerServices(fakeServices);
+
+      expect(servicesManager.registerService.mock.calls.length).toBe(2);
+    });
+  });
+
+  describe('registerService()', () => {
+    it('logs a warning if the service is null or undefined', () => {
+      const undefinedService = undefined;
+      const nullService = null;
+
+      servicesManager.registerService(undefinedService);
+      servicesManager.registerService(nullService);
+
+      expect(log.warn.mock.calls.length).toBe(2);
+    });
+
+    it('logs a warning if the service does not have a name', () => {
+      const serviceWithEmptyName = { name: '', hide: jest.fn() };
+      const serviceWithoutName = { hide: jest.fn() };
+
+      servicesManager.registerService(serviceWithEmptyName);
+      servicesManager.registerService(serviceWithoutName);
+
+      expect(log.warn.mock.calls.length).toBe(2);
+    });
+
+    it('tracks which services have been registered', () => {
+      const service = {
+        name: 'UINotificationService',
+      };
+
+      servicesManager.registerService(service);
+
+      expect(servicesManager.registeredServiceNames).toContain(service.name);
+    });
+
+    it('logs a warning if the service has an name that has already been registered', () => {
+      const service = { name: 'UINotificationService' };
+
+      servicesManager.registerService(service);
+      servicesManager.registerService(service);
+
+      expect(log.warn.mock.calls.length).toBe(1);
+    });
+  });
+});

platform/viewer/src/App.js

@@ -185,7 +185,7 @@ class App extends Component {
 }
 
 function _initServices(services) {
-  services.forEach(service => servicesManager.register(service));
+  servicesManager.registerServices(services);
 }
 
 /**