feat(test): Setup unit testing

Makefile

@@ -30,3 +30,6 @@ restart-detached:
 
 validate-no-uncommitted-package-lock-changes:
 	git diff --exit-code package-lock.json
+
+test:
+	docker exec -it edx.gradebook jest 

package.json

@@ -47,6 +47,7 @@
     "whatwg-fetch": "^2.0.3"
   },
   "devDependencies": {
+    "axios-mock-adapter": "^1.15.0",
     "babel-cli": "^6.26.0",
     "babel-eslint": "^8.2.2",
     "babel-jest": "^22.4.0",

src/data/actions/cohorts.test.js

@@ -0,0 +1,73 @@
+import configureMockStore from 'redux-mock-store';
+import MockAdapter from 'axios-mock-adapter';
+import thunk from 'redux-thunk';
+
+import apiClient from '../apiClient';
+import { fetchCohorts } from './cohorts';
+import {
+  STARTED_FETCHING_COHORTS,
+  GOT_COHORTS,
+  ERROR_FETCHING_COHORTS,
+} from '../constants/actionTypes/cohorts';
+
+const mockStore = configureMockStore([thunk]);
+const axiosMock = new MockAdapter(apiClient);
+
+describe('actions', () => {
+  afterEach(() => {
+    axiosMock.reset();
+  });
+
+  describe('fetchCohorts', () => {
+    const courseId = 'course-v1:edX+DemoX+Demo_Course';
+
+    it('dispatches success action after fetching cohorts', () => {
+      const responseData = {
+        cohorts: [
+          {
+            assignment_type: 'manual',
+            group_id: null,
+            id: 1,
+            name: 'default_group',
+            user_count: 2,
+            user_partition_id: null,
+          },
+          {
+            assignment_type: 'auto',
+            group_id: null,
+            id: 2,
+            name: 'auto_group',
+            user_count: 5,
+            user_partition_id: null,
+          }],
+      };
+      const expectedActions = [
+        { type: STARTED_FETCHING_COHORTS },
+        { type: GOT_COHORTS, cohorts: responseData.cohorts },
+      ];
+      const store = mockStore();
+
+      axiosMock.onGet(`http://localhost:18000/courses/${courseId}/cohorts/`)
+        .replyOnce(200, JSON.stringify(responseData));
+
+      return store.dispatch(fetchCohorts(courseId)).then(() => {
+        expect(store.getActions()).toEqual(expectedActions);
+      });
+    });
+
+    it('dispatches failure action after fetching cohorts', () => {
+      const expectedActions = [
+        { type: STARTED_FETCHING_COHORTS },
+        { type: ERROR_FETCHING_COHORTS },
+      ];
+      const store = mockStore();
+
+      axiosMock.onGet(`http://localhost:18000/courses/${courseId}/cohorts/`)
+        .replyOnce(500, JSON.stringify({}));
+
+      return store.dispatch(fetchCohorts(courseId)).then(() => {
+        expect(store.getActions()).toEqual(expectedActions);
+      });
+    });
+  });
+});

src/setupTest.js

@@ -4,3 +4,7 @@ import Enzyme from 'enzyme';
 import Adapter from 'enzyme-adapter-react-16';
 
 Enzyme.configure({ adapter: new Adapter() });
+
+// These configuration values are usually set in webpack's EnvironmentPlugin however
+// Jest does not use webpack so we need to set these so for testing
+process.env.LMS_BASE_URL = 'http://localhost:18000';