Firebase Stub: added support for data remove

__mocks__/__tests__/gatsby-plugin-firebase.test.js

@@ -384,5 +384,63 @@ describe('FirebaseStub', () => {
       expect(snapshotValue[existingResume.id]).toBeTruthy();
       expect(snapshotValue[existingResume.id].name).toBe(existingResume.name);
     });
+
+    it('triggers callback with removed resume when removing an existing one', async () => {
+      const userUid = DatabaseConstants.user1.uid;
+
+      let valueCallbackSnapshotValue = null;
+      const valueCallback = jest.fn((snapshot) => {
+        valueCallbackSnapshotValue = snapshot.val();
+      });
+      FirebaseStub.database()
+        .ref(DatabaseConstants.resumesPath)
+        .orderByChild('user')
+        .equalTo(userUid)
+        .on('value', valueCallback);
+      await waitFor(() => valueCallback.mock.calls[0][0]);
+      expect(valueCallback.mock.calls).toHaveLength(1);
+      valueCallback.mockClear();
+      expect(valueCallbackSnapshotValue).not.toBeNull();
+      expect(Object.keys(valueCallbackSnapshotValue)).toHaveLength(2);
+      Object.values(valueCallbackSnapshotValue).forEach((resume) =>
+        expect(resume.user).toEqual(userUid),
+      );
+      valueCallbackSnapshotValue = null;
+
+      let childRemovedCallbackSnapshotValue = null;
+      const childRemovedCallback = jest.fn((snapshot) => {
+        childRemovedCallbackSnapshotValue = snapshot.val();
+      });
+      FirebaseStub.database()
+        .ref(DatabaseConstants.resumesPath)
+        .orderByChild('user')
+        .equalTo(userUid)
+        .on('child_removed', childRemovedCallback);
+
+      const removedResume = (
+        await FirebaseStub.database()
+          .ref(
+            `${DatabaseConstants.resumesPath}/${DatabaseConstants.demoStateResume1Id}`,
+          )
+          .once('value')
+      ).val();
+      expect(removedResume).toBeTruthy();
+      expect(removedResume.user).toEqual(userUid);
+      await FirebaseStub.database()
+        .ref(`${DatabaseConstants.resumesPath}/${removedResume.id}`)
+        .remove();
+
+      await waitFor(() => childRemovedCallback.mock.calls[0][0]);
+      expect(childRemovedCallback.mock.calls).toHaveLength(1);
+      childRemovedCallback.mockClear();
+      expect(childRemovedCallbackSnapshotValue).toBeTruthy();
+      expect(childRemovedCallbackSnapshotValue.id).toBe(removedResume.id);
+
+      await waitFor(() => valueCallback.mock.calls[0][0]);
+      expect(valueCallback.mock.calls).toHaveLength(1);
+      valueCallback.mockClear();
+      expect(valueCallbackSnapshotValue).toBeTruthy();
+      expect(removedResume.id in valueCallbackSnapshotValue).toBe(false);
+    });
   });
 });

__mocks__/gatsby-plugin-firebase/constants/database.js

@@ -1,6 +1,7 @@
 import AuthConstants from './auth';
 
 const valueEventType = 'value';
+const childRemovedEventType = 'child_removed';
 
 const resumesPath = 'resumes';
 const usersPath = 'users';
@@ -24,6 +25,10 @@ class Database {
     return valueEventType;
   }
 
+  static get childRemovedEventType() {
+    return childRemovedEventType;
+  }
+
   static get resumesPath() {
     return resumesPath;
   }

__mocks__/gatsby-plugin-firebase/database/dataSnapshot.js

@@ -1,16 +1,6 @@
 /* eslint-disable no-underscore-dangle */
-import DatabaseConstants from '../constants/database';
-
 class DataSnapshot {
-  constructor(eventType, getData, value = undefined) {
-    if (!eventType) {
-      throw new Error('eventType must be provided.');
-    } else if (typeof eventType !== 'string') {
-      throw new Error('eventType should be a string.');
-    }
-
-    this._eventType = eventType;
-
+  constructor(getData, value = undefined) {
     if (!getData) {
       throw new Error('getData must be provided.');
     } else if (typeof getData !== 'function') {
@@ -22,21 +12,13 @@ class DataSnapshot {
     this._value = value;
   }
 
-  get eventType() {
-    return this._eventType;
-  }
-
   get value() {
     return this._value;
   }
 
   val() {
-    if (this.eventType === DatabaseConstants.valueEventType) {
     return typeof this.value !== 'undefined' ? this.value : this._getData();
   }
-
-    return undefined;
-  }
 }
 
 export default DataSnapshot;

__mocks__/gatsby-plugin-firebase/database/reference.js

@@ -17,7 +17,7 @@ class Reference {
 
     this._uuid = uuidv4();
 
-    this._dataSnapshots = {};
+    this._dataSnapshot = null;
 
     if (!getDatabaseData) {
       throw new Error('getDatabaseData must be provided.');
@@ -91,31 +91,42 @@ class Reference {
       throw new Error('value must be provided.');
     }
 
-    this._setDatabaseData(this.path, value);
-
-    this.debounceEventCallback(DatabaseConstants.valueEventType);
+    const currentData = this._getData();
 
     const pathElements = this.path.split('/');
+    let parentReference = null;
     if (pathElements.length === 2) {
-      const parentReference = this._getReference(pathElements[0]);
+      parentReference = this._getReference(pathElements[0]);
+    }
+
+    this._setDatabaseData(this.path, value);
+
+    if (value === null) {
       if (parentReference) {
+        parentReference.debounceEventCallback(
+          DatabaseConstants.childRemovedEventType,
+          currentData,
+        );
         parentReference.debounceEventCallback(DatabaseConstants.valueEventType);
       }
+    } else {
+      const eventType = DatabaseConstants.valueEventType;
+      this.debounceEventCallback(eventType);
+      if (parentReference) {
+        parentReference.debounceEventCallback(eventType);
+      }
     }
   }
 
-  debounceEventCallback(eventType) {
+  debounceEventCallback(eventType, snapshotValue = undefined) {
     if (!(eventType in this.eventCallbacks)) {
       return;
     }
 
-    let snapshot = new DataSnapshot(eventType, () => this._getData(), null);
-
-    if (this.path === DatabaseConstants.connectedPath) {
-      snapshot = new DataSnapshot(eventType, () => this._getData(), true);
-    } else if (this.path === DatabaseConstants.resumesPath) {
-      snapshot = new DataSnapshot(eventType, () => this._getData());
-    }
+    const snapshot =
+      this.path === DatabaseConstants.connectedPath
+        ? new DataSnapshot(() => this._getData(), true)
+        : new DataSnapshot(() => this._getData(), snapshotValue);
 
     const debouncedEventCallback = debounce(
       this.eventCallbacks[eventType],
@@ -139,23 +150,27 @@ class Reference {
   }
 
   on(eventType, callback) {
-    if (eventType !== DatabaseConstants.valueEventType) {
-      return;
-    }
-
     this._eventCallbacks[eventType] = callback;
 
+    if (eventType === DatabaseConstants.valueEventType) {
       this.debounceEventCallback(eventType);
     }
+  }
 
   async once(eventType) {
-    const newDataSnapshot = new DataSnapshot(eventType, () => this._getData());
-    const existingDataSnapshot = this._dataSnapshots[newDataSnapshot.eventType];
-    if (existingDataSnapshot) {
-      return Promise.resolve(existingDataSnapshot);
+    if (!eventType) {
+      throw new Error('eventType must be provided.');
+    } else if (typeof eventType !== 'string') {
+      throw new Error('eventType should be a string.');
     }
 
-    this._dataSnapshots[newDataSnapshot.eventType] = newDataSnapshot;
+    if (this._dataSnapshot) {
+      return Promise.resolve(this._dataSnapshot);
+    }
+
+    const newDataSnapshot = new DataSnapshot(() => this._getData());
+    this._dataSnapshot = newDataSnapshot;
+
     return Promise.resolve(newDataSnapshot);
   }
 
@@ -170,6 +185,12 @@ class Reference {
     return Promise.resolve(true);
   }
 
+  async remove() {
+    this._setData(null);
+
+    return Promise.resolve(true);
+  }
+
   async set(value) {
     this._setData(value);