Added Nav Plugin tests

Summary:
Here I added two tests to test the persisted state reducer in the navigation pliugin.

I uncovered that my state reducer is not pure, as it calls the Date constructor, but I will fix this in a future update by passing the date recorded on the Android device when the nav event occurs and sending that via the socket connection.

For now I have modified the state reducer to take a date as part of the payload on a nav_event, or if none exists record the date as before. Also, if a page has no uri, but we want to record a nav event, I send null uri from the Android side. This doesn't send the uri as null to flipper; the uri object property simply doesn't exist. In this case I explicitly cast the undefined value for uri to null.

Reviewed By: jknoxville

Differential Revision: D16330958

fbshipit-source-id: fe338ea3a244df6ef33356bc7fdef8da9291dc68

src/plugins/navigation/__tests__/testNavigationPlugin.node.js

@@ -0,0 +1,106 @@
+/**
+ * Copyright 2018-present Facebook.
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ * @format
+ * @flow strict-local
+ */
+
+import NavigationPlugin from '../';
+
+import type {PersistedState} from '../';
+
+function constructPersistedStateMock(): PersistedState {
+  return {
+    navigationEvents: [],
+  };
+}
+
+function constructPersistedStateMockWithEvents(): PersistedState {
+  return {
+    navigationEvents: [
+      {
+        uri: 'mock://this_is_a_mock_uri/mock/1',
+        date: DATE_MOCK_2,
+      },
+      {
+        uri: 'mock://this_is_a_mock_uri/mock/2',
+        date: DATE_MOCK_3,
+      },
+    ],
+  };
+}
+
+const DATE_MOCK_1 = new Date(2019, 6, 17, 11, 10, 0, 0);
+const DATE_MOCK_2 = new Date(2019, 6, 18, 11, 10, 0, 0);
+const DATE_MOCK_3 = new Date(2019, 6, 19, 11, 10, 0, 0);
+
+const INCOMING_NAV_EVENT = {
+  uri: 'mock://this_is_a_mock_uri/mock',
+  date: DATE_MOCK_1,
+};
+
+const INCOMING_UNDEFINED_NAV_EVENT = {
+  date: DATE_MOCK_1,
+};
+
+test('add incoming nav event to persisted state', () => {
+  const persistedState = constructPersistedStateMock();
+  const reducer = NavigationPlugin.persistedStateReducer;
+  if (reducer) {
+    const newPersistedState = reducer(
+      persistedState,
+      'nav_event',
+      INCOMING_NAV_EVENT,
+    );
+    expect(newPersistedState.navigationEvents).toEqual([
+      {
+        uri: 'mock://this_is_a_mock_uri/mock',
+        date: DATE_MOCK_1,
+      },
+    ]);
+  } else {
+    expect(reducer).not.toBeNull();
+  }
+});
+
+test('add incoming nav event to persisted state with nav events', () => {
+  const persistedState = constructPersistedStateMockWithEvents();
+  const reducer = NavigationPlugin.persistedStateReducer;
+  if (reducer) {
+    const newPersistedState = reducer(
+      persistedState,
+      'nav_event',
+      INCOMING_NAV_EVENT,
+    );
+    expect(newPersistedState.navigationEvents).toEqual([
+      ...persistedState.navigationEvents,
+      {
+        uri: 'mock://this_is_a_mock_uri/mock',
+        date: DATE_MOCK_1,
+      },
+    ]);
+  } else {
+    expect(reducer).not.toBeNull();
+  }
+});
+
+test('add incoming nav event with undefined uri to persisted state', () => {
+  const persistedState = constructPersistedStateMock();
+  const reducer = NavigationPlugin.persistedStateReducer;
+  if (reducer) {
+    const newPersistedState = reducer(
+      persistedState,
+      'nav_event',
+      INCOMING_UNDEFINED_NAV_EVENT,
+    );
+    expect(newPersistedState.navigationEvents).toEqual([
+      {
+        uri: null,
+        date: DATE_MOCK_1,
+      },
+    ]);
+  } else {
+    expect(reducer).not.toBeNull();
+  }
+});

src/plugins/navigation/index.js

@@ -14,12 +14,12 @@ type State = {||};
 type Data = {||};
 
 type NavigationEvent = {|
-  date: Date,
-  uri: ?String,
+  date: ?Date,
+  uri: ?string,
 |};
 
-type PersistedState = {|
-  navigationEvents: [NavigationEvent],
+export type PersistedState = {|
+  navigationEvents: Array<NavigationEvent>,
 |};
 
 export default class extends FlipperPlugin<State, {}, PersistedState> {
@@ -35,7 +35,7 @@ export default class extends FlipperPlugin<State, {}, PersistedState> {
   static persistedStateReducer = (
     persistedState: PersistedState,
     method: string,
-    payload: Object,
+    payload: NavigationEvent,
   ): $Shape<PersistedState> => {
     switch (method) {
       case 'nav_event':
@@ -43,7 +43,10 @@ export default class extends FlipperPlugin<State, {}, PersistedState> {
           ...persistedState,
           navigationEvents: [
             ...persistedState.navigationEvents,
-            {uri: payload.uri, date: new Date()},
+            {
+              uri: payload.uri === undefined ? null : payload.uri,
+              date: payload.date || new Date(),
+            },
           ],
         };
       default:
@@ -55,7 +58,7 @@ export default class extends FlipperPlugin<State, {}, PersistedState> {
 
   onKeyboardAction = (action: string) => {
     if (action === 'clear') {
-      this.props.setPersistedState({data: []});
+      this.props.setPersistedState({navigationEvents: []});
     }
   };