Firebase Stub: resolving ESLint errors

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

@@ -119,36 +119,30 @@ describe('FirebaseStub', () => {
       const demoStateResume1 = resumes[DatabaseConstants.demoStateResume1Id];
       expect(demoStateResume1).toBeTruthy();
       expect(demoStateResume1.id).toEqual(DatabaseConstants.demoStateResume1Id);
-      expect(demoStateResume1.user).toEqual(
-        FirebaseStub.database().anonymousUser1.uid,
-      );
+      expect(demoStateResume1.user).toEqual(DatabaseConstants.user1.uid);
       const demoStateResume2 = resumes[DatabaseConstants.demoStateResume2Id];
       expect(demoStateResume2).toBeTruthy();
       expect(demoStateResume2.id).toEqual(DatabaseConstants.demoStateResume2Id);
-      expect(demoStateResume2.user).toEqual(
-        FirebaseStub.database().anonymousUser2.uid,
-      );
+      expect(demoStateResume2.user).toEqual(DatabaseConstants.user2.uid);
       const initialStateResume =
         resumes[DatabaseConstants.initialStateResumeId];
       expect(initialStateResume).toBeTruthy();
       expect(initialStateResume.id).toEqual(
         DatabaseConstants.initialStateResumeId,
       );
-      expect(initialStateResume.user).toEqual(
-        FirebaseStub.database().anonymousUser1.uid,
-      );
+      expect(initialStateResume.user).toEqual(DatabaseConstants.user1.uid);
 
       const usersRef = FirebaseStub.database().ref(DatabaseConstants.usersPath);
       const usersDataSnapshot = await usersRef.once('value');
       const users = usersDataSnapshot.val();
       expect(users).toBeTruthy();
       expect(Object.keys(users)).toHaveLength(2);
-      const anonymousUser1 = users[FirebaseStub.database().anonymousUser1.uid];
+      const anonymousUser1 = users[DatabaseConstants.user1.uid];
       expect(anonymousUser1).toBeTruthy();
-      expect(anonymousUser1).toEqual(FirebaseStub.database().anonymousUser1);
-      const anonymousUser2 = users[FirebaseStub.database().anonymousUser2.uid];
+      expect(anonymousUser1).toEqual(DatabaseConstants.user1);
+      const anonymousUser2 = users[DatabaseConstants.user2.uid];
       expect(anonymousUser2).toBeTruthy();
-      expect(anonymousUser2).toEqual(FirebaseStub.database().anonymousUser2);
+      expect(anonymousUser2).toEqual(DatabaseConstants.user2);
     });
 
     it('retrieves resume if it exists', async () => {
@@ -184,16 +178,12 @@ describe('FirebaseStub', () => {
 
       const user = (
         await FirebaseStub.database()
-          .ref(
-            `${DatabaseConstants.usersPath}/${
-              FirebaseStub.database().anonymousUser1.uid
-            }`,
-          )
+          .ref(`${DatabaseConstants.usersPath}/${DatabaseConstants.user1.uid}`)
           .once('value')
       ).val();
 
       expect(user).toBeTruthy();
-      expect(user).toEqual(FirebaseStub.database().anonymousUser1);
+      expect(user).toEqual(DatabaseConstants.user1);
     });
 
     it('retrieves null if user does not exist', async () => {
@@ -243,14 +233,14 @@ describe('FirebaseStub', () => {
       FirebaseStub.database()
         .ref(DatabaseConstants.resumesPath)
         .orderByChild('user')
-        .equalTo(FirebaseStub.database().anonymousUser1.uid)
+        .equalTo(DatabaseConstants.user1.uid)
         .on('value', (snapshot) => {
           snapshotValue = snapshot.val();
         });
 
       expect(Object.keys(snapshotValue)).toHaveLength(2);
       Object.values(snapshotValue).forEach((resume) =>
-        expect(resume.user).toEqual(FirebaseStub.database().anonymousUser1.uid),
+        expect(resume.user).toEqual(DatabaseConstants.user1.uid),
       );
     });
   });

__mocks__/gatsby-plugin-firebase.js

@@ -1,9 +1,7 @@
 import Auth from './gatsby-plugin-firebase/auth/auth';
 import Database from './gatsby-plugin-firebase/database/database';
-import {
-  AuthConstants,
-  DatabaseConstants,
-} from './gatsby-plugin-firebase/constants';
+import AuthConstants from './gatsby-plugin-firebase/constants/auth';
+import DatabaseConstants from './gatsby-plugin-firebase/constants/database';
 
 class FirebaseStub {
   static auth() {
@@ -11,7 +9,7 @@ class FirebaseStub {
   }
 
   static database() {
-    return new Database();
+    return Database.instance;
   }
 }
 

__mocks__/gatsby-plugin-firebase/constants.js

@@ -1,4 +0,0 @@
-import AuthConstants from './constants/auth';
-import DatabaseConstants from './constants/database';
-
-export { AuthConstants, DatabaseConstants };

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

@@ -1,10 +1,22 @@
+import AuthConstants from './auth';
+
 const resumesPath = 'resumes';
 const usersPath = 'users';
 const connectedPath = '/.info/connected';
+
 const demoStateResume1Id = 'demo_1';
 const demoStateResume2Id = 'demo_2';
 const initialStateResumeId = 'initst';
 
+const user1 = {
+  uid: AuthConstants.anonymousUser1.uid,
+  isAnonymous: AuthConstants.anonymousUser1.isAnonymous,
+};
+const user2 = {
+  uid: AuthConstants.anonymousUser2.uid,
+  isAnonymous: AuthConstants.anonymousUser2.isAnonymous,
+};
+
 class Database {
   static get resumesPath() {
     return resumesPath;
@@ -29,6 +41,14 @@ class Database {
   static get initialStateResumeId() {
     return initialStateResumeId;
   }
+
+  static get user1() {
+    return user1;
+  }
+
+  static get user2() {
+    return user2;
+  }
 }
 
 export default Database;

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

@@ -2,102 +2,85 @@ import path from 'path';
 import fs from 'fs';
 import { v4 as uuidv4 } from 'uuid';
 
-import { AuthConstants, DatabaseConstants } from '../constants';
+import DatabaseConstants from '../constants/database';
 import Reference from './reference';
 
-class Database {
-  static #instance = undefined;
-  #uuid = '';
-  #data = {};
-  #references = {};
-  #anonymousUser1 = undefined;
-  #anonymousUser2 = undefined;
+const singleton = Symbol('');
+const singletonEnforcer = Symbol('');
 
-  constructor() {
-    if (Database.#instance) {
-      return Database.#instance;
-    }
-
-    Database.#instance = this;
-
-    this.#uuid = uuidv4();
-    this.#anonymousUser1 = {
-      uid: AuthConstants.anonymousUser1.uid,
-      isAnonymous: AuthConstants.anonymousUser1.isAnonymous,
-    };
-    this.#anonymousUser2 = {
-      uid: AuthConstants.anonymousUser2.uid,
-      isAnonymous: AuthConstants.anonymousUser2.isAnonymous,
-    };
-  }
-
-  get anonymousUser1() {
-    return this.#anonymousUser1;
-  }
-
-  get anonymousUser2() {
-    return this.#anonymousUser2;
-  }
-
-  get uuid() {
-    return this.#uuid;
-  }
-
-  static readFile(fileRelativePath) {
+const readFile = (fileRelativePath) => {
   const fileAbsolutePath = path.resolve(__dirname, fileRelativePath);
   const fileBuffer = fs.readFileSync(fileAbsolutePath);
   const fileData = JSON.parse(fileBuffer);
   return fileData;
+};
+
+class Database {
+  constructor(enforcer) {
+    if (enforcer !== singletonEnforcer) {
+      throw new Error('Cannot construct singleton');
+    }
+
+    this.uuidField = uuidv4();
+    this.dataField = {};
+    this.referencesField = {};
+  }
+
+  static get instance() {
+    if (!this[singleton]) {
+      this[singleton] = new Database(singletonEnforcer);
+    }
+
+    return this[singleton];
+  }
+
+  get uuid() {
+    return this.uuidField;
   }
 
   initializeData() {
     const resumes = {};
 
-    const demoStateResume1 = Database.readFile(
-      '../../../src/data/demoState.json',
-    );
-    let date = new Date('December 15, 2020 11:20:25');
+    const demoStateResume1 = readFile('../../../src/data/demoState.json');
+    const date = new Date('December 15, 2020 11:20:25');
     demoStateResume1.updatedAt = date.valueOf();
     date.setMonth(date.getMonth() - 2);
     demoStateResume1.createdAt = date.valueOf();
-    demoStateResume1.user = this.anonymousUser1.uid;
+    demoStateResume1.user = DatabaseConstants.user1.uid;
     resumes[DatabaseConstants.demoStateResume1Id] = demoStateResume1;
 
     const demoStateResume2 = JSON.parse(JSON.stringify(demoStateResume1));
-    demoStateResume2.user = this.anonymousUser2.uid;
+    demoStateResume2.user = DatabaseConstants.user2.uid;
     resumes[DatabaseConstants.demoStateResume2Id] = demoStateResume2;
 
-    const initialStateResume = Database.readFile(
-      '../../../src/data/initialState.json',
-    );
+    const initialStateResume = readFile('../../../src/data/initialState.json');
     initialStateResume.updatedAt = date.valueOf();
     initialStateResume.createdAt = date.valueOf();
-    initialStateResume.user = this.anonymousUser1.uid;
+    initialStateResume.user = DatabaseConstants.user1.uid;
     resumes[DatabaseConstants.initialStateResumeId] = initialStateResume;
 
-    for (var key in resumes) {
+    Object.keys(resumes).forEach((key) => {
       const resume = resumes[key];
-
       resume.id = key;
       resume.name = `Test Resume ${key}`;
-    }
+    });
 
-    this.#data[DatabaseConstants.resumesPath] = resumes;
+    this.dataField[DatabaseConstants.resumesPath] = resumes;
 
     const users = {};
-    users[this.anonymousUser1.uid] = this.anonymousUser1;
-    users[this.anonymousUser2.uid] = this.anonymousUser2;
-    this.#data[DatabaseConstants.usersPath] = users;
+    users[DatabaseConstants.user1.uid] = DatabaseConstants.user1;
+    users[DatabaseConstants.user2.uid] = DatabaseConstants.user2;
+    this.dataField[DatabaseConstants.usersPath] = users;
   }
 
-  ref(path) {
-    const newRef = new Reference(path, () => this.#data);
-    const existingRef = this.#references[newRef.path];
+  ref(referencePath) {
+    const newRef = new Reference(referencePath, () => this.dataField);
+    const existingRef = this.referencesField[newRef.path];
     if (existingRef) {
       return existingRef;
     }
 
-    this.#references[newRef.path] = newRef;
+    this.referencesField[newRef.path] = newRef;
     return newRef;
   }
 }

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

@@ -1,6 +1,6 @@
 import { v4 as uuidv4 } from 'uuid';
 
-import { DatabaseConstants } from '../constants';
+import DatabaseConstants from '../constants/database';
 import DataSnapshot from './dataSnapshot';
 
 const rootPath = '.';

src/pages/app/__tests__/builder.test.js

@@ -63,7 +63,7 @@ describe('Builder', () => {
       await FirebaseStub.auth().signInAnonymously();
     });
 
-    await waitFor(() => expect(mockUpdateFunction).toHaveBeenCalledTimes(1), {
+    await waitFor(() => mockUpdateFunction.mock.calls[0][0], {
       timeout: DebounceWaitTime,
     });
     mockUpdateFunction.mockClear();

src/pages/app/__tests__/dashboard.test.js

@@ -18,7 +18,7 @@ beforeEach(() => {
 
 describe('Dashboard', () => {
   let resumes = null;
-  const user = FirebaseStub.database().anonymousUser1;
+  const user = DatabaseConstants.user1;
 
   beforeEach(async () => {
     resumes = (