Add or Remove subscriptions on subscription events. Add tests

Author: borisyankov

src/events/eventActions.js

@@ -44,12 +44,12 @@ const processEvent = (dispatch, event, getState) => {
       if (event.op === 'add') {
         dispatch({
           type: EVENT_SUBSCRIPTION_ADD,
-          event,
+          subscriptions: event.subscriptions,
         });
       } else if (event.op === 'remove') {
         dispatch({
           type: EVENT_SUBSCRIPTION_REMOVE,
-          event,
+          subscriptions: event.subscriptions,
         });
       }
       break;

src/subscriptions/__tests__/subscriptionsReducers-test.js

@@ -0,0 +1,157 @@
+import {
+  EVENT_SUBSCRIPTION_ADD,
+  EVENT_SUBSCRIPTION_REMOVE,
+} from '../../constants';
+import subscriptionsReducers from '../subscriptionsReducers';
+
+describe('subscriptionsReducers', () => {
+  test('on unrecognized action, returns input state unchanged', () => {
+    const prevState = { hello: 'world' };
+    const newState = subscriptionsReducers(prevState, {});
+    expect(newState).toEqual(prevState);
+  });
+
+  describe('EVENT_SUBSCRIPTION_ADD', () => {
+    test('if new subscriptions do not exist in state, add them', () => {
+      const prevState = [];
+      const action = {
+        type: EVENT_SUBSCRIPTION_ADD,
+        subscriptions: [
+          {
+            name: 'some stream',
+            stream_id: 1,
+          },
+          {
+            name: 'some other stream',
+            stream_id: 2,
+          }
+        ],
+      };
+      const expectedState = [
+        {
+          name: 'some stream',
+          stream_id: 1,
+        },
+        {
+          name: 'some other stream',
+          stream_id: 2,
+        }
+      ];
+
+      const newState = subscriptionsReducers(prevState, action);
+
+      expect(newState).toEqual(expectedState);
+    });
+
+    test('if some of subscriptions already exist, do not add them', () => {
+      const prevState = [
+        {
+          color: 'red',
+          stream_id: 1,
+          name: 'some stream'
+        }
+      ];
+      const action = {
+        type: EVENT_SUBSCRIPTION_ADD,
+        subscriptions: [
+          {
+            name: 'some stream',
+            stream_id: 1,
+          },
+          {
+            name: 'some other stream',
+            stream_id: 2,
+          }
+        ],
+      };
+      const expectedState = [
+        {
+          color: 'red',
+          name: 'some stream',
+          stream_id: 1,
+        },
+        {
+          name: 'some other stream',
+          stream_id: 2,
+        }
+      ];
+
+      const newState = subscriptionsReducers(prevState, action);
+
+      expect(newState).toEqual(expectedState);
+    });
+  });
+
+  describe('EVENT_SUBSCRIPTION_REMOVE', () => {
+    test('removes subscriptions from state', () => {
+      const prevState = [
+        {
+          color: 'red',
+          stream_id: 1,
+          name: 'some stream'
+        },
+        {
+          color: 'green',
+          stream_id: 2,
+          name: 'other stream'
+        },
+        {
+          color: 'blue',
+          stream_id: 3,
+          name: 'third stream'
+        },
+      ];
+      const action = {
+        type: EVENT_SUBSCRIPTION_REMOVE,
+        subscriptions: [
+          {
+            name: 'some stream',
+            stream_id: 1,
+          },
+          {
+            name: 'some other stream',
+            stream_id: 2,
+          },
+        ],
+      };
+      const expectedState = [
+        {
+          color: 'blue',
+          stream_id: 3,
+          name: 'third stream'
+        },
+      ];
+
+      const newState = subscriptionsReducers(prevState, action);
+
+      expect(newState).toEqual(expectedState);
+    });
+
+    test('removes subscriptions that exist, do nothing if not', () => {
+      const prevState = [
+        {
+          name: 'some stream',
+          stream_id: 1,
+        },
+      ];
+      const action = {
+        type: EVENT_SUBSCRIPTION_REMOVE,
+        subscriptions: [
+          {
+            name: 'some stream',
+            stream_id: 1,
+          },
+          {
+            name: 'some other stream',
+            stream_id: 2,
+          }
+        ],
+      };
+      const expectedState = [];
+
+      const newState = subscriptionsReducers(prevState, action);
+
+      expect(newState).toEqual(expectedState);
+    });
+  });
+});

src/subscriptions/subscriptionsReducers.js

@@ -11,9 +11,16 @@ export default (state = initialState, action) => {
     case REALM_INIT:
       return action.data.subscriptions;
     case EVENT_SUBSCRIPTION_ADD:
-      return state;
-    case EVENT_SUBSCRIPTION_REMOVE:
-      return state;
+      return state.concat(
+        action.subscriptions.filter(x =>
+          !state.find(y => x.stream_id === y.stream_id)
+        )
+      );
+    case EVENT_SUBSCRIPTION_REMOVE: {
+      return state.filter(x =>
+        !action.subscriptions.find(y => x.stream_id === y.stream_id)
+      );
+    }
     default:
       return state;
   }