feat(routes): childRoutes are not required for root module (#657)

* feat(routes): childRoutes are not required for root module

* feat(routes): removed duplicate test and refactored moduleRoute in createRoute

* feat(routes): updated test case with mocked hasChildRoutes

* feat(routes): updated test case description

__tests__/universal/routes.spec.jsx

@@ -18,6 +18,7 @@ import ReactTestUtils from 'react-dom/test-utils';
 import { fromJS } from 'immutable';
 
 import createRoutes from '../../src/universal/routes';
+import hasChildRoutes from '../../src/universal/utils/hasChildRoutes';
 
 jest.mock('holocron-module-route', () => () => null);
 jest.mock('@americanexpress/one-app-ducks/lib/errorReporting', () => ({
@@ -27,6 +28,7 @@ jest.mock('@americanexpress/one-app-ducks/lib/errorReporting', () => ({
     meta,
   })),
 }));
+jest.mock('../../src/universal/utils/hasChildRoutes');
 
 describe('routes', () => {
   const store = {
@@ -44,15 +46,23 @@ describe('routes', () => {
 
   beforeEach(() => jest.clearAllMocks());
 
-  it('should set up the root module route first', () => {
+  it('should return array of length 2', () => {
+    const RootRoute = createRoutes(store);
+    expect(RootRoute.length).toBe(2);
+  });
+
+  it('should return RootRoute props with path if RootModule has no childroutes', () => {
+    hasChildRoutes.mockReturnValueOnce(false);
     const RootRoute = createRoutes(store)[0];
     expect(ReactTestUtils.isElement(RootRoute)).toBe(true);
-    expect(RootRoute.props).toEqual({ moduleName: 'fakeRootModule', store });
+    expect(RootRoute.props).toEqual({ moduleName: 'fakeRootModule', path: '/', store });
   });
 
-  it('should not define a path on the root module', () => {
+  it('should return RootRoute props without path if RootModule has childroutes', () => {
+    hasChildRoutes.mockReturnValueOnce(true);
     const RootRoute = createRoutes(store)[0];
-    expect(RootRoute.props.path).toBe(undefined);
+    expect(ReactTestUtils.isElement(RootRoute)).toBe(true);
+    expect(RootRoute.props).toEqual({ moduleName: 'fakeRootModule', store });
   });
 
   it('should set up a default 404', () => {

__tests__/universal/utils/hasChildRoutes.spec.js

@@ -0,0 +1,27 @@
+/*
+ * Copyright 2022 American Express Travel Related Services Company, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
+ * or implied. See the License for the specific language governing
+ * permissions and limitations under the License.
+ */
+
+import hasChildRoutes from '../../../src/universal/utils/hasChildRoutes';
+
+it('hasChildRoutes returns false', () => {
+  [undefined, null, '', [], {}].forEach((value) => {
+    expect(hasChildRoutes(value)).toBeFalsy();
+  });
+});
+
+it('hasChildRoutes returns true', () => {
+  expect(hasChildRoutes({ childRoutes: [] })).toBe(true);
+});

docs/api/modules/Routing.md

@@ -39,7 +39,7 @@ Enables components and modules to define their own child routes. `childRoutes` c
 route, array of routes or a function which accepts the Redux store as the sole argument and returns
 a single route or array of routes.
 
-One App requires the Root Module to have at least one child route defined. This can be either `<Route>` or `<ModuleRoute>` with a `path`.
+`childRoutes` is optional for Root Module. `childRoutes` can be either `<Route>` or `<ModuleRoute>` with a `path`. If `childRoutes` is not defined, the default path `/` is added to the root route.
 
 ```js
 const MyModule = () => { /* jsx */ };

src/universal/routes.jsx

@@ -22,11 +22,15 @@ import React from 'react';
 import ModuleRoute from 'holocron-module-route';
 import { Route } from '@americanexpress/one-app-router';
 import { applicationError, clearError } from '@americanexpress/one-app-ducks';
+import { getModule } from 'holocron';
+import hasChildRoutes from './utils/hasChildRoutes';
 
 const createRoutes = (store) => {
   const rootModuleName = store.getState().getIn(['config', 'rootModuleName']);
+  const rootHasChildRoutes = hasChildRoutes(getModule(rootModuleName));
+
   return [
-    <ModuleRoute moduleName={rootModuleName} store={store} />,
+    <ModuleRoute moduleName={rootModuleName} store={store} path={rootHasChildRoutes ? undefined : '/'} />,
     <Route
       path="*"
       component={() => 'Not found'}

src/universal/utils/hasChildRoutes.js

@@ -0,0 +1,19 @@
+/*
+ * Copyright 2022 American Express Travel Related Services Company, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
+ * or implied. See the License for the specific language governing
+ * permissions and limitations under the License.
+ */
+
+const hasChildRoutes = (module) => module && !!module.childRoutes;
+
+export default hasChildRoutes;