Merge pull request #423 from gianantoniopini/develop

Unit testing environment set up and addition of some unit tests

.eslintrc

@@ -8,8 +8,13 @@
     "FileReader": true,
     "localStorage": true
   },
-  "extends": ["airbnb", "prettier"],
+  "extends": [
-  "plugins": ["prettier"],
+    "airbnb",
+    "plugin:jest/recommended",
+    "plugin:jest/style",
+    "prettier"
+  ],
+  "plugins": ["jest", "prettier"],
   "rules": {
     "import/no-extraneous-dependencies": ["error", { "devDependencies": true }],
     "react/jsx-filename-extension": [1, { "extensions": [".js", ".jsx"] }],

.gitignore

@@ -20,6 +20,9 @@ coverage
 # nyc test coverage
 .nyc_output
 
+# Coverage directory used by Jest
+test-coverage
+
 # Grunt intermediate storage (http://gruntjs.com/creating-plugins#storing-task-files)
 .grunt
 

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

@@ -0,0 +1,555 @@
+import { waitFor } from '@testing-library/react';
+import FirebaseStub, {
+  AuthConstants,
+  DatabaseConstants,
+} from '../gatsby-plugin-firebase';
+
+describe('FirebaseStub', () => {
+  describe('auth', () => {
+    afterEach(() => {
+      FirebaseStub.auth().dispose();
+    });
+
+    it('reuses existing Auth instance', () => {
+      const auth1 = FirebaseStub.auth();
+      const auth2 = FirebaseStub.auth();
+
+      expect(auth1.uuid).toBeTruthy();
+      expect(auth2.uuid).toBeTruthy();
+      expect(auth1.uuid).toEqual(auth2.uuid);
+    });
+
+    it('returns anonymous user 1 when signing in anonymously', async () => {
+      const user = await FirebaseStub.auth().signInAnonymously();
+
+      expect(user).toBeTruthy();
+      expect(user).toEqual(AuthConstants.anonymousUser1);
+    });
+
+    it('calls onAuthStateChanged observer with anonymous user 1 when signing in anonymously', async () => {
+      let user = null;
+      let error = null;
+      FirebaseStub.auth().onAuthStateChanged(
+        (_user) => {
+          user = _user;
+        },
+        (_error) => {
+          error = _error;
+        },
+      );
+
+      await FirebaseStub.auth().signInAnonymously();
+
+      expect(user).toBeTruthy();
+      expect(user).toEqual(AuthConstants.anonymousUser1);
+      expect(error).toBeNull();
+    });
+
+    it('onAuthStateChanged unsubscribe removes observer', () => {
+      const observer = () => {};
+      const unsubscribe = FirebaseStub.auth().onAuthStateChanged(observer);
+      expect(unsubscribe).toBeTruthy();
+      expect(FirebaseStub.auth().onAuthStateChangedObservers).toHaveLength(1);
+      expect(FirebaseStub.auth().onAuthStateChangedObservers[0]).toEqual(
+        observer,
+      );
+
+      unsubscribe();
+
+      expect(FirebaseStub.auth().onAuthStateChangedObservers).toHaveLength(0);
+    });
+  });
+
+  describe('database', () => {
+    beforeEach(() => {
+      FirebaseStub.database().initializeData();
+    });
+
+    it('reuses existing Database instance', () => {
+      const database1 = FirebaseStub.database();
+      const database2 = FirebaseStub.database();
+
+      expect(database1.uuid).toBeTruthy();
+      expect(database2.uuid).toBeTruthy();
+      expect(database1.uuid).toEqual(database2.uuid);
+    });
+
+    describe('ref function', () => {
+      it('reuses existing Reference instance', () => {
+        const ref1 = FirebaseStub.database().ref(
+          `${DatabaseConstants.resumesPath}/123`,
+        );
+        const ref2 = FirebaseStub.database().ref(
+          `${DatabaseConstants.resumesPath}/123`,
+        );
+
+        expect(ref1).toBeTruthy();
+        expect(ref2).toBeTruthy();
+        expect(ref1).toEqual(ref2);
+      });
+
+      it('leading slash in reference path is ignored', () => {
+        const path = `${DatabaseConstants.resumesPath}/123`;
+
+        const ref1 = FirebaseStub.database().ref(path);
+        expect(ref1).toBeTruthy();
+        expect(ref1.path).toEqual(path);
+
+        const ref2 = FirebaseStub.database().ref(`/${path}`);
+        expect(ref2).toBeTruthy();
+        expect(ref2).toEqual(ref1);
+      });
+    });
+
+    it('ServerValue.TIMESTAMP returns current time in milliseconds', () => {
+      const now = new Date().getTime();
+      const timestamp = FirebaseStub.database.ServerValue.TIMESTAMP;
+
+      expect(timestamp).toBeTruthy();
+      expect(timestamp).toBeGreaterThanOrEqual(now);
+    });
+
+    it('initializing data sets up resumes and users', async () => {
+      const resumesRef = FirebaseStub.database().ref(
+        DatabaseConstants.resumesPath,
+      );
+      const resumesDataSnapshot = await resumesRef.once('value');
+      const resumes = resumesDataSnapshot.val();
+      expect(resumes).toBeTruthy();
+      expect(Object.keys(resumes)).toHaveLength(3);
+      const demoStateResume1 = resumes[DatabaseConstants.demoStateResume1Id];
+      expect(demoStateResume1).toBeTruthy();
+      expect(demoStateResume1.id).toEqual(DatabaseConstants.demoStateResume1Id);
+      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(DatabaseConstants.user2.uid);
+      const initialStateResume =
+        resumes[DatabaseConstants.initialStateResumeId];
+      expect(initialStateResume).toBeTruthy();
+      expect(initialStateResume.id).toEqual(
+        DatabaseConstants.initialStateResumeId,
+      );
+      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[DatabaseConstants.user1.uid];
+      expect(anonymousUser1).toBeTruthy();
+      expect(anonymousUser1).toEqual(DatabaseConstants.user1);
+      const anonymousUser2 = users[DatabaseConstants.user2.uid];
+      expect(anonymousUser2).toBeTruthy();
+      expect(anonymousUser2).toEqual(DatabaseConstants.user2);
+    });
+
+    it('retrieves resume if it exists', async () => {
+      const resume = (
+        await FirebaseStub.database()
+          .ref(
+            `${DatabaseConstants.resumesPath}/${DatabaseConstants.demoStateResume1Id}`,
+          )
+          .once('value')
+      ).val();
+
+      expect(resume).toBeTruthy();
+      expect(resume.id).toEqual(DatabaseConstants.demoStateResume1Id);
+    });
+
+    it('retrieves null if resume does not exist', async () => {
+      const resumeId = 'invalidResumeId';
+
+      const resume = (
+        await FirebaseStub.database()
+          .ref(`${DatabaseConstants.resumesPath}/${resumeId}`)
+          .once('value')
+      ).val();
+
+      expect(resume).toBeNull();
+    });
+
+    it('retrieves user if it exists', async () => {
+      const user = (
+        await FirebaseStub.database()
+          .ref(`${DatabaseConstants.usersPath}/${DatabaseConstants.user1.uid}`)
+          .once('value')
+      ).val();
+
+      expect(user).toBeTruthy();
+      expect(user).toEqual(DatabaseConstants.user1);
+    });
+
+    it('retrieves null if user does not exist', async () => {
+      const userId = 'invalidUserId';
+
+      const user = (
+        await FirebaseStub.database()
+          .ref(`${DatabaseConstants.usersPath}/${userId}`)
+          .once('value')
+      ).val();
+
+      expect(user).toBeNull();
+    });
+
+    describe('on function', () => {
+      describe('value event', () => {
+        it('triggers event with true if on the connected reference path', async () => {
+          let snapshotValue = null;
+
+          FirebaseStub.database()
+            .ref(DatabaseConstants.connectedPath)
+            .on('value', (snapshot) => {
+              snapshotValue = snapshot.val();
+            });
+
+          await waitFor(() =>
+            snapshotValue ? Promise.resolve(true) : Promise.reject(),
+          );
+
+          expect(snapshotValue).not.toBeNull();
+          expect(snapshotValue).toBe(true);
+        });
+
+        it('triggers event with resumes if on the resumes reference path', async () => {
+          const resumesDataSnapshot = await FirebaseStub.database()
+            .ref(DatabaseConstants.resumesPath)
+            .once('value');
+          const resumes = resumesDataSnapshot.val();
+          let snapshotValue = null;
+
+          FirebaseStub.database()
+            .ref(DatabaseConstants.resumesPath)
+            .on('value', (snapshot) => {
+              snapshotValue = snapshot.val();
+            });
+
+          await waitFor(() =>
+            snapshotValue ? Promise.resolve(true) : Promise.reject(),
+          );
+
+          expect(snapshotValue).not.toBeNull();
+          expect(snapshotValue).toEqual(resumes);
+        });
+      });
+    });
+
+    it('can filter resumes by user', async () => {
+      let snapshotValue = null;
+
+      FirebaseStub.database()
+        .ref(DatabaseConstants.resumesPath)
+        .orderByChild('user')
+        .equalTo(DatabaseConstants.user1.uid)
+        .on('value', (snapshot) => {
+          snapshotValue = snapshot.val();
+        });
+
+      await waitFor(() =>
+        snapshotValue ? Promise.resolve(true) : Promise.reject(),
+      );
+
+      expect(snapshotValue).not.toBeNull();
+      expect(Object.keys(snapshotValue)).toHaveLength(2);
+      Object.values(snapshotValue).forEach((resume) =>
+        expect(resume.user).toEqual(DatabaseConstants.user1.uid),
+      );
+    });
+
+    it('previously set query parameters are not kept when retrieving reference again', async () => {
+      let reference = null;
+
+      reference = FirebaseStub.database().ref(DatabaseConstants.resumesPath);
+      expect(reference).toBeTruthy();
+      const { uuid } = reference;
+      expect(reference.orderByChildPath).toHaveLength(0);
+      expect(reference.equalToValue).toHaveLength(0);
+
+      reference = FirebaseStub.database()
+        .ref(DatabaseConstants.resumesPath)
+        .orderByChild('user')
+        .equalTo('testuser1');
+      expect(reference).toBeTruthy();
+      expect(reference.uuid).toBe(uuid);
+      expect(reference.orderByChildPath).toBe('user');
+      expect(reference.equalToValue).toBe('testuser1');
+
+      reference = FirebaseStub.database().ref(DatabaseConstants.resumesPath);
+      expect(reference).toBeTruthy();
+      expect(reference.uuid).toBe(uuid);
+      expect(reference.orderByChildPath).toHaveLength(0);
+      expect(reference.equalToValue).toHaveLength(0);
+    });
+
+    describe('set function', () => {
+      it('inserts data', async () => {
+        const existingResume = (
+          await FirebaseStub.database()
+            .ref(
+              `${DatabaseConstants.resumesPath}/${DatabaseConstants.demoStateResume1Id}`,
+            )
+            .once('value')
+        ).val();
+        expect(existingResume).toBeTruthy();
+
+        const newResume = JSON.parse(JSON.stringify(existingResume));
+        newResume.id = 'newre1';
+        newResume.name = `Test Resume ${newResume.id}`;
+        await FirebaseStub.database()
+          .ref(`${DatabaseConstants.resumesPath}/${newResume.id}`)
+          .set(newResume);
+
+        const actualResume = (
+          await FirebaseStub.database()
+            .ref(`${DatabaseConstants.resumesPath}/${newResume.id}`)
+            .once('value')
+        ).val();
+        expect(actualResume).toBeTruthy();
+        expect(actualResume).toEqual(newResume);
+      });
+
+      it('triggers events', async () => {
+        let snapshotValue = null;
+        const callback = jest.fn((snapshot) => {
+          snapshotValue = snapshot.val();
+        });
+        FirebaseStub.database()
+          .ref(DatabaseConstants.resumesPath)
+          .orderByChild('user')
+          .equalTo(DatabaseConstants.user1.uid)
+          .on('value', callback);
+        await waitFor(() => callback.mock.calls[0][0]);
+        callback.mockClear();
+        snapshotValue = null;
+
+        const existingResume = (
+          await FirebaseStub.database()
+            .ref(
+              `${DatabaseConstants.resumesPath}/${DatabaseConstants.demoStateResume1Id}`,
+            )
+            .once('value')
+        ).val();
+        expect(existingResume).toBeTruthy();
+
+        const newResume = JSON.parse(JSON.stringify(existingResume));
+        newResume.id = 'newre1';
+        newResume.name = `Test Resume ${newResume.id}`;
+        await FirebaseStub.database()
+          .ref(`${DatabaseConstants.resumesPath}/${newResume.id}`)
+          .set(newResume);
+
+        await waitFor(() => callback.mock.calls[0][0]);
+
+        expect(callback.mock.calls).toHaveLength(1);
+        expect(snapshotValue).not.toBeNull();
+        expect(Object.keys(snapshotValue)).toHaveLength(3);
+        expect(snapshotValue[newResume.id]).toBeTruthy();
+        expect(snapshotValue[newResume.id]).toEqual(newResume);
+      });
+    });
+
+    describe('update function', () => {
+      it('can spy on it', async () => {
+        const referencePath = `${DatabaseConstants.resumesPath}/123456`;
+        const functionSpy = jest.spyOn(
+          FirebaseStub.database().ref(referencePath),
+          'update',
+        );
+        const updateArgument = 'test value 123';
+
+        await FirebaseStub.database().ref(referencePath).update(updateArgument);
+
+        expect(functionSpy).toHaveBeenCalledTimes(1);
+        const functionCallArgument = functionSpy.mock.calls[0][0];
+        expect(functionCallArgument).toBeTruthy();
+        expect(functionCallArgument).toEqual(updateArgument);
+      });
+
+      it('updates data', async () => {
+        const resumeId = DatabaseConstants.demoStateResume1Id;
+        const existingResume = (
+          await FirebaseStub.database()
+            .ref(`${DatabaseConstants.resumesPath}/${resumeId}`)
+            .once('value')
+        ).val();
+        expect(existingResume).toBeTruthy();
+
+        const resumeName = 'Test Resume renamed';
+        existingResume.name = resumeName;
+        await FirebaseStub.database()
+          .ref(`${DatabaseConstants.resumesPath}/${resumeId}`)
+          .update(existingResume);
+
+        const actualResume = (
+          await FirebaseStub.database()
+            .ref(`${DatabaseConstants.resumesPath}/${resumeId}`)
+            .once('value')
+        ).val();
+        expect(actualResume).toBeTruthy();
+        expect(existingResume).toEqual(actualResume);
+        expect(actualResume.name).toEqual(resumeName);
+      });
+
+      it('triggers events', async () => {
+        let snapshotValue = null;
+        const callback = jest.fn((snapshot) => {
+          snapshotValue = snapshot.val();
+        });
+        FirebaseStub.database()
+          .ref(DatabaseConstants.resumesPath)
+          .orderByChild('user')
+          .equalTo(DatabaseConstants.user1.uid)
+          .on('value', callback);
+        await waitFor(() => callback.mock.calls[0][0]);
+        callback.mockClear();
+        snapshotValue = null;
+
+        const existingResume = (
+          await FirebaseStub.database()
+            .ref(
+              `${DatabaseConstants.resumesPath}/${DatabaseConstants.demoStateResume1Id}`,
+            )
+            .once('value')
+        ).val();
+        expect(existingResume).toBeTruthy();
+
+        existingResume.name = 'Test Resume renamed';
+        await FirebaseStub.database()
+          .ref(`${DatabaseConstants.resumesPath}/${existingResume.id}`)
+          .update(existingResume);
+
+        await waitFor(() => callback.mock.calls[0][0]);
+
+        expect(callback.mock.calls).toHaveLength(1);
+        expect(snapshotValue).not.toBeNull();
+        expect(Object.keys(snapshotValue)).toHaveLength(2);
+        expect(snapshotValue[existingResume.id]).toBeTruthy();
+        expect(snapshotValue[existingResume.id]).toEqual(existingResume);
+      });
+    });
+
+    describe('remove function', () => {
+      it('deletes data', async () => {
+        const resumeId = DatabaseConstants.demoStateResume1Id;
+        const removedResume = (
+          await FirebaseStub.database()
+            .ref(`${DatabaseConstants.resumesPath}/${resumeId}`)
+            .once('value')
+        ).val();
+        expect(removedResume).toBeTruthy();
+
+        await FirebaseStub.database()
+          .ref(`${DatabaseConstants.resumesPath}/${resumeId}`)
+          .remove();
+
+        const actualResume = (
+          await FirebaseStub.database()
+            .ref(`${DatabaseConstants.resumesPath}/${resumeId}`)
+            .once('value')
+        ).val();
+        expect(actualResume).toBeNull();
+      });
+
+      it('triggers events', 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]);
+        valueCallback.mockClear();
+        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);
+        expect(childRemovedCallbackSnapshotValue).toBeTruthy();
+        expect(childRemovedCallbackSnapshotValue).toEqual(removedResume);
+
+        await waitFor(() => valueCallback.mock.calls[0][0]);
+        expect(valueCallback.mock.calls).toHaveLength(1);
+        expect(valueCallbackSnapshotValue).toBeTruthy();
+        expect(removedResume.id in valueCallbackSnapshotValue).toBe(false);
+      });
+    });
+
+    describe('off function', () => {
+      it('removes event callbacks', 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]);
+        valueCallback.mockClear();
+        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();
+
+        FirebaseStub.database().ref(DatabaseConstants.resumesPath).off();
+
+        await FirebaseStub.database()
+          .ref(`${DatabaseConstants.resumesPath}/${removedResume.id}`)
+          .remove();
+
+        expect(childRemovedCallback.mock.calls).toHaveLength(0);
+        expect(childRemovedCallbackSnapshotValue).toBeNull();
+        expect(valueCallback.mock.calls).toHaveLength(0);
+        expect(valueCallbackSnapshotValue).toBeNull();
+      });
+    });
+  });
+});

__mocks__/file-mock.js

@@ -0,0 +1,2 @@
+const mockFile = 'test-file-stub';
+export default mockFile;

__mocks__/gatsby-plugin-firebase.js

@@ -0,0 +1,24 @@
+import Auth from './gatsby-plugin-firebase/auth/auth';
+import Database from './gatsby-plugin-firebase/database/database';
+import AuthConstants from './gatsby-plugin-firebase/constants/auth';
+import DatabaseConstants from './gatsby-plugin-firebase/constants/database';
+
+class FirebaseStub {
+  static auth() {
+    return Auth.instance;
+  }
+
+  static database() {
+    return Database.instance;
+  }
+}
+
+FirebaseStub.database.ServerValue = {};
+Object.defineProperty(FirebaseStub.database.ServerValue, 'TIMESTAMP', {
+  get() {
+    return new Date().getTime();
+  },
+});
+
+export default FirebaseStub;
+export { AuthConstants, DatabaseConstants };

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

@@ -0,0 +1,58 @@
+/* eslint-disable no-underscore-dangle */
+import { v4 as uuidv4 } from 'uuid';
+
+import Constants from '../constants/auth';
+
+const singleton = Symbol('');
+const singletonEnforcer = Symbol('');
+
+class Auth {
+  constructor(enforcer) {
+    if (enforcer !== singletonEnforcer) {
+      throw new Error('Cannot construct singleton');
+    }
+
+    this._uuid = uuidv4();
+    this._onAuthStateChangedObservers = [];
+  }
+
+  static get instance() {
+    if (!this[singleton]) {
+      this[singleton] = new Auth(singletonEnforcer);
+    }
+
+    return this[singleton];
+  }
+
+  get uuid() {
+    return this._uuid;
+  }
+
+  get onAuthStateChangedObservers() {
+    return this._onAuthStateChangedObservers;
+  }
+
+  dispose() {
+    this._onAuthStateChangedObservers = [];
+  }
+
+  onAuthStateChanged(observer) {
+    this.onAuthStateChangedObservers.push(observer);
+
+    return () => {
+      this._onAuthStateChangedObservers = this.onAuthStateChangedObservers.filter(
+        (obs) => obs !== observer,
+      );
+    };
+  }
+
+  async signInAnonymously() {
+    const user = Constants.anonymousUser1;
+
+    this.onAuthStateChangedObservers.forEach((observer) => observer(user));
+
+    return Promise.resolve(user);
+  }
+}
+
+export default Auth;

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

@@ -0,0 +1,27 @@
+const anonymousUser1 = {
+  displayName: 'Anonymous User 1',
+  email: 'anonymous1@noemail.com',
+  isAnonymous: true,
+  name: 'Anonymous 1',
+  uid: 'anonym123',
+};
+
+const anonymousUser2 = {
+  displayName: 'Anonymous User 2',
+  email: 'anonymous2@noemail.com',
+  isAnonymous: true,
+  name: 'Anonymous 2',
+  uid: 'anonym456',
+};
+
+class Auth {
+  static get anonymousUser1() {
+    return anonymousUser1;
+  }
+
+  static get anonymousUser2() {
+    return anonymousUser2;
+  }
+}
+
+export default Auth;

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

@@ -0,0 +1,65 @@
+import AuthConstants from './auth';
+
+const valueEventType = 'value';
+const childRemovedEventType = 'child_removed';
+
+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 valueEventType() {
+    return valueEventType;
+  }
+
+  static get childRemovedEventType() {
+    return childRemovedEventType;
+  }
+
+  static get resumesPath() {
+    return resumesPath;
+  }
+
+  static get usersPath() {
+    return usersPath;
+  }
+
+  static get connectedPath() {
+    return connectedPath;
+  }
+
+  static get demoStateResume1Id() {
+    return demoStateResume1Id;
+  }
+
+  static get demoStateResume2Id() {
+    return demoStateResume2Id;
+  }
+
+  static get initialStateResumeId() {
+    return initialStateResumeId;
+  }
+
+  static get user1() {
+    return user1;
+  }
+
+  static get user2() {
+    return user2;
+  }
+}
+
+export default Database;

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

@@ -0,0 +1,24 @@
+/* eslint-disable no-underscore-dangle */
+class DataSnapshot {
+  constructor(getData, value = undefined) {
+    if (!getData) {
+      throw new Error('getData must be provided.');
+    } else if (typeof getData !== 'function') {
+      throw new Error('getData should be a function.');
+    }
+
+    this._getData = getData;
+
+    this._value = value;
+  }
+
+  get value() {
+    return this._value;
+  }
+
+  val() {
+    return typeof this.value !== 'undefined' ? this.value : this._getData();
+  }
+}
+
+export default DataSnapshot;

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

@@ -0,0 +1,156 @@
+/* eslint-disable no-underscore-dangle */
+import path from 'path';
+import fs from 'fs';
+import { v4 as uuidv4 } from 'uuid';
+
+import DatabaseConstants from '../constants/database';
+import Reference from './reference';
+
+const singleton = Symbol('');
+const singletonEnforcer = Symbol('');
+
+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._uuid = uuidv4();
+    this._data = {};
+    this._references = {};
+  }
+
+  static get instance() {
+    if (!this[singleton]) {
+      this[singleton] = new Database(singletonEnforcer);
+    }
+
+    return this[singleton];
+  }
+
+  get uuid() {
+    return this._uuid;
+  }
+
+  _getData(dataPath) {
+    if (!dataPath) {
+      throw new Error('dataPath must be provided.');
+    }
+
+    const dataPathElements = dataPath.split('/');
+    if (!(dataPathElements[0] in this._data)) {
+      return null;
+    }
+
+    if (dataPathElements.length === 1) {
+      return this._data[dataPathElements[0]];
+    }
+
+    if (dataPathElements.length === 2) {
+      if (!(dataPathElements[1] in this._data[dataPathElements[0]])) {
+        return null;
+      }
+
+      return this._data[dataPathElements[0]][dataPathElements[1]];
+    }
+
+    return null;
+  }
+
+  _getReference(referencePath) {
+    return referencePath in this._references
+      ? this._references[referencePath]
+      : null;
+  }
+
+  _setData(dataPath, value) {
+    if (!dataPath) {
+      throw new Error('dataPath must be provided.');
+    }
+
+    if (typeof value === 'undefined') {
+      throw new Error('value is undefined.');
+    }
+
+    const dataPathElements = dataPath.split('/');
+    if (dataPathElements.length !== 2) {
+      return;
+    }
+
+    if (!(dataPathElements[0] in this._data)) {
+      return;
+    }
+
+    if (!dataPathElements[1]) {
+      return;
+    }
+
+    if (value === null) {
+      delete this._data[dataPathElements[0]][dataPathElements[1]];
+    } else {
+      this._data[dataPathElements[0]][dataPathElements[1]] = value;
+    }
+  }
+
+  initializeData() {
+    const resumes = {};
+
+    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 = DatabaseConstants.user1.uid;
+    resumes[DatabaseConstants.demoStateResume1Id] = demoStateResume1;
+
+    const demoStateResume2 = JSON.parse(JSON.stringify(demoStateResume1));
+    demoStateResume2.user = DatabaseConstants.user2.uid;
+    resumes[DatabaseConstants.demoStateResume2Id] = demoStateResume2;
+
+    const initialStateResume = readFile('../../../src/data/initialState.json');
+    initialStateResume.updatedAt = date.valueOf();
+    initialStateResume.createdAt = date.valueOf();
+    initialStateResume.user = DatabaseConstants.user1.uid;
+    resumes[DatabaseConstants.initialStateResumeId] = initialStateResume;
+
+    Object.keys(resumes).forEach((key) => {
+      const resume = resumes[key];
+      resume.id = key;
+      resume.name = `Test Resume ${key}`;
+    });
+
+    this._data[DatabaseConstants.resumesPath] = resumes;
+
+    const users = {};
+    users[DatabaseConstants.user1.uid] = DatabaseConstants.user1;
+    users[DatabaseConstants.user2.uid] = DatabaseConstants.user2;
+    this._data[DatabaseConstants.usersPath] = users;
+  }
+
+  ref(referencePath) {
+    const newRef = new Reference(
+      referencePath,
+      (dataPath) => this._getData(dataPath),
+      (dataPath, value) => this._setData(dataPath, value),
+      (refPath) => this._getReference(refPath),
+    );
+
+    const existingRef = this._getReference(newRef.path);
+    if (existingRef) {
+      existingRef.initializeQueryParameters();
+      return existingRef;
+    }
+
+    this._references[newRef.path] = newRef;
+    return newRef;
+  }
+}
+
+export default Database;

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

@@ -0,0 +1,213 @@
+/* eslint-disable no-underscore-dangle */
+import { v4 as uuidv4 } from 'uuid';
+import { debounce } from 'lodash';
+
+import DatabaseConstants from '../constants/database';
+import DataSnapshot from './dataSnapshot';
+
+const parsePath = (path) => {
+  if (!path) {
+    throw new Error('path must be provided.');
+  } else if (typeof path !== 'string') {
+    throw new Error('path should be a string.');
+  } else {
+    let parsedPath = path.trim();
+
+    if (parsedPath[0] === '/') {
+      parsedPath = parsedPath.substring(1);
+    }
+
+    return parsedPath;
+  }
+};
+
+class Reference {
+  constructor(path, getDatabaseData, setDatabaseData, getReference) {
+    this._path = parsePath(path);
+
+    this._uuid = uuidv4();
+
+    if (this.path === DatabaseConstants.connectedPath) {
+      this._dataSnapshot = new DataSnapshot(() => {}, true);
+    } else {
+      this._dataSnapshot = new DataSnapshot(() => this._getData());
+    }
+
+    if (!getDatabaseData) {
+      throw new Error('getDatabaseData must be provided.');
+    } else if (typeof getDatabaseData !== 'function') {
+      throw new Error('getDatabaseData should be a function.');
+    }
+
+    this._getDatabaseData = getDatabaseData;
+
+    if (!setDatabaseData) {
+      throw new Error('setDatabaseData must be provided.');
+    } else if (typeof getDatabaseData !== 'function') {
+      throw new Error('setDatabaseData should be a function.');
+    }
+
+    this._setDatabaseData = setDatabaseData;
+
+    if (!getReference) {
+      throw new Error('getReference must be provided.');
+    } else if (typeof getDatabaseData !== 'function') {
+      throw new Error('getReference should be a function.');
+    }
+
+    this._getReference = getReference;
+
+    this._eventCallbacks = {};
+
+    this.initializeQueryParameters();
+  }
+
+  get path() {
+    return this._path;
+  }
+
+  get uuid() {
+    return this._uuid;
+  }
+
+  get eventCallbacks() {
+    return this._eventCallbacks;
+  }
+
+  get orderByChildPath() {
+    return this._orderByChildPath;
+  }
+
+  get equalToValue() {
+    return this._equalToValue;
+  }
+
+  _getData() {
+    const databaseData = this._getDatabaseData(this.path);
+
+    if (!databaseData) {
+      return null;
+    }
+
+    if (this.orderByChildPath && this.equalToValue) {
+      return Object.fromEntries(
+        Object.entries(databaseData).filter(
+          ([, value]) => value[this.orderByChildPath] === this.equalToValue,
+        ),
+      );
+    }
+
+    return databaseData;
+  }
+
+  _getParent() {
+    const pathElements = this.path.split('/');
+
+    let parent = null;
+    if (pathElements.length === 2) {
+      parent = this._getReference(pathElements[0]);
+    }
+
+    return parent;
+  }
+
+  _handleDataUpdate(value) {
+    if (typeof value === 'undefined') {
+      throw new Error('value must be provided.');
+    }
+
+    const currentData = this._getData();
+    const parentReference = this._getParent();
+
+    this._setDatabaseData(this.path, value);
+
+    if (value === null) {
+      if (parentReference) {
+        parentReference.triggerEventCallback(
+          DatabaseConstants.childRemovedEventType,
+          currentData,
+        );
+      }
+    } else {
+      this.triggerEventCallback(DatabaseConstants.valueEventType);
+    }
+
+    if (parentReference) {
+      parentReference.triggerEventCallback(DatabaseConstants.valueEventType);
+    }
+  }
+
+  triggerEventCallback(eventType, snapshotValue = undefined) {
+    if (!(eventType in this.eventCallbacks)) {
+      return;
+    }
+
+    const snapshot =
+      this.path === DatabaseConstants.connectedPath
+        ? this._dataSnapshot
+        : new DataSnapshot(() => this._getData(), snapshotValue);
+
+    const debouncedEventCallback = debounce(
+      this.eventCallbacks[eventType],
+      100,
+    );
+    debouncedEventCallback(snapshot);
+  }
+
+  equalTo(value) {
+    this._equalToValue = value;
+    return this;
+  }
+
+  initializeQueryParameters() {
+    this._orderByChildPath = '';
+    this._equalToValue = '';
+  }
+
+  off() {
+    this._eventCallbacks = {};
+  }
+
+  on(eventType, callback) {
+    this.eventCallbacks[eventType] = callback;
+
+    if (eventType === DatabaseConstants.valueEventType) {
+      this.triggerEventCallback(eventType);
+    }
+  }
+
+  async once(eventType) {
+    if (!eventType) {
+      throw new Error('eventType must be provided.');
+    } else if (typeof eventType !== 'string') {
+      throw new Error('eventType should be a string.');
+    }
+
+    return Promise.resolve(this._dataSnapshot);
+  }
+
+  orderByChild(path) {
+    this._orderByChildPath = path;
+    return this;
+  }
+
+  async update(value) {
+    this._handleDataUpdate(value);
+
+    return Promise.resolve(true);
+  }
+
+  async remove() {
+    this._handleDataUpdate(null);
+
+    return Promise.resolve(true);
+  }
+
+  async set(value) {
+    this._handleDataUpdate(value);
+
+    return Promise.resolve(true);
+  }
+}
+
+export default Reference;

__mocks__/gatsby.js

@@ -0,0 +1,80 @@
+import React from 'react';
+
+const Gatsby = jest.requireActual('gatsby');
+
+const fluidImageShapes = [
+  {
+    aspectRatio: 2,
+    src: 'test_image.jpg',
+    srcSet: 'some srcSet',
+    srcSetWebp: 'some srcSetWebp',
+    sizes: '(max-width: 600px) 100vw, 600px',
+    base64: 'string_of_base64',
+  },
+  {
+    aspectRatio: 3,
+    src: 'test_image_2.jpg',
+    srcSet: 'some other srcSet',
+    srcSetWebp: 'some other srcSetWebp',
+    sizes: '(max-width: 400px) 100vw, 400px',
+    base64: 'string_of_base64',
+  },
+];
+
+const useStaticQuery = () => ({
+  site: {
+    siteMetadata: {
+      title: 'Test title',
+      description: 'Test description',
+      author: 'Test author',
+      siteUrl: 'https://testsiteurl/',
+    },
+  },
+  file: {
+    childImageSharp: {
+      fluid: fluidImageShapes[0],
+    },
+  },
+  onyx: {
+    childImageSharp: {
+      fluid: fluidImageShapes[0],
+    },
+  },
+  pikachu: {
+    childImageSharp: {
+      fluid: fluidImageShapes[1],
+    },
+  },
+  gengar: {
+    childImageSharp: {
+      fluid: fluidImageShapes[0],
+    },
+  },
+  castform: {
+    childImageSharp: {
+      fluid: fluidImageShapes[1],
+    },
+  },
+  glalie: {
+    childImageSharp: {
+      fluid: fluidImageShapes[0],
+    },
+  },
+  celebi: {
+    childImageSharp: {
+      fluid: fluidImageShapes[1],
+    },
+  },
+});
+
+module.exports = {
+  ...Gatsby,
+  graphql: jest.fn(),
+  Link: jest.fn().mockImplementation(({ to, ...rest }) =>
+    React.createElement('a', {
+      ...rest,
+      href: to,
+    }),
+  ),
+  useStaticQuery,
+};

jest-preprocess.js

@@ -0,0 +1,5 @@
+const babelOptions = {
+  presets: ['babel-preset-gatsby'],
+};
+
+module.exports = require('babel-jest').createTransformer(babelOptions);

jest.config.js

@@ -0,0 +1,36 @@
+module.exports = {
+  testRegex: '/*.test.js$',
+  collectCoverage: true,
+  collectCoverageFrom: [
+    '**/*.{js,jsx}',
+    '!\\.cache/**',
+    '!node_modules/**',
+    '!public/**',
+    '!test-coverage/**',
+  ],
+  coverageDirectory: 'test-coverage',
+  coverageThreshold: {
+    global: {
+      branches: 0,
+      functions: 0,
+      lines: 0,
+      statements: 0,
+    },
+  },
+  verbose: true,
+  transform: {
+    '^.+\\.jsx?$': `<rootDir>/jest-preprocess.js`,
+  },
+  moduleNameMapper: {
+    '.+\\.(css|styl|less|sass|scss)$': `identity-obj-proxy`,
+    '.+\\.(jpg|jpeg|png|gif|eot|otf|webp|svg|ttf|woff|woff2|mp4|webm|wav|mp3|m4a|aac|oga)$': `<rootDir>/__mocks__/file-mock.js`,
+  },
+  testPathIgnorePatterns: [`node_modules`, `\\.cache`],
+  transformIgnorePatterns: [`node_modules/(?!(gatsby)/)`],
+  globals: {
+    __PATH_PREFIX__: ``,
+  },
+  testURL: `http://localhost`,
+  setupFiles: [`<rootDir>/loadershim.js`],
+  setupFilesAfterEnv: [`<rootDir>/jest.setup.js`],
+};

jest.setup.js

@@ -0,0 +1 @@
+import '@testing-library/jest-dom/extend-expect';

loadershim.js

@@ -0,0 +1,3 @@
+global.___loader = {
+  enqueue: jest.fn(),
+};

package.json

@@ -7,13 +7,14 @@
   "scripts": {
     "lint": "eslint .",
     "lint:fix": "eslint --fix .",
+    "prebuild": "npm run test",
     "build": "gatsby build",
     "develop": "gatsby develop",
     "format": "prettier --write \"**/*.{js,jsx,ts,tsx,json,md}\"",
     "start": "npm run develop",
     "serve": "gatsby serve",
     "clean": "gatsby clean",
-    "test": "echo \"Write tests! -> https://gatsby.dev/unit-testing\" && exit 1"
+    "test": "jest"
   },
   "dependencies": {
     "@material-ui/core": "^4.11.2",
@@ -61,14 +62,21 @@
     "yup": "^0.32.8"
   },
   "devDependencies": {
+    "@testing-library/jest-dom": "^5.11.8",
+    "@testing-library/react": "^11.2.3",
+    "babel-jest": "^26.6.3",
+    "babel-preset-gatsby": "^0.10.0",
     "eslint": "^7.17.0",
     "eslint-config-airbnb": "^18.2.1",
     "eslint-config-prettier": "^7.1.0",
     "eslint-loader": "^4.0.2",
+    "eslint-plugin-jest": "^24.1.3",
     "eslint-plugin-jsx-a11y": "^6.4.1",
     "eslint-plugin-prettier": "^3.3.1",
     "eslint-plugin-react": "^7.22.0",
     "gatsby-plugin-eslint": "^2.0.8",
+    "identity-obj-proxy": "^3.0.0",
+    "jest": "^26.6.3",
     "prettier": "2.2.1",
     "stylelint": "^13.8.0",
     "stylelint-config-standard": "^20.0.0",

src/contexts/DatabaseContext.js

@@ -128,4 +128,7 @@ export default DatabaseContext;
 
 const memoizedProvider = memo(DatabaseProvider);
 
-export { memoizedProvider as DatabaseProvider };
+export {
+  memoizedProvider as DatabaseProvider,
+  DEBOUNCE_WAIT_TIME as DebounceWaitTime,
+};

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

@@ -0,0 +1,147 @@
+import React from 'react';
+import {
+  act,
+  fireEvent,
+  render,
+  screen,
+  waitFor,
+} from '@testing-library/react';
+
+import FirebaseStub, { DatabaseConstants } from 'gatsby-plugin-firebase';
+
+import { SettingsProvider } from '../../../contexts/SettingsContext';
+import { ModalProvider } from '../../../contexts/ModalContext';
+import { UserProvider } from '../../../contexts/UserContext';
+import {
+  DatabaseProvider,
+  DebounceWaitTime,
+} from '../../../contexts/DatabaseContext';
+import { ResumeProvider } from '../../../contexts/ResumeContext';
+import { StorageProvider } from '../../../contexts/StorageContext';
+import Builder from '../builder';
+
+describe('Builder', () => {
+  let resumeId = null;
+  let resume = null;
+  let mockUpdateFunction = null;
+
+  beforeEach(async () => {
+    FirebaseStub.database().initializeData();
+
+    resumeId = DatabaseConstants.demoStateResume1Id;
+    resume = (
+      await FirebaseStub.database()
+        .ref(`${DatabaseConstants.resumesPath}/${resumeId}`)
+        .once('value')
+    ).val();
+    mockUpdateFunction = jest.spyOn(
+      FirebaseStub.database().ref(
+        `${DatabaseConstants.resumesPath}/${resumeId}`,
+      ),
+      'update',
+    );
+
+    render(
+      <SettingsProvider>
+        <ModalProvider>
+          <UserProvider>
+            <DatabaseProvider>
+              <ResumeProvider>
+                <StorageProvider>
+                  <Builder id={resume.id} />
+                </StorageProvider>
+              </ResumeProvider>
+            </DatabaseProvider>
+          </UserProvider>
+        </ModalProvider>
+      </SettingsProvider>,
+    );
+
+    await act(async () => {
+      await FirebaseStub.auth().signInAnonymously();
+    });
+
+    await waitFor(() => mockUpdateFunction.mock.calls[0][0], {
+      timeout: DebounceWaitTime,
+    });
+    mockUpdateFunction.mockClear();
+  });
+
+  describe('renders', () => {
+    it('first and last name', async () => {
+      expect(
+        screen.getByLabelText(new RegExp('first name', 'i')),
+      ).toHaveDisplayValue(resume.profile.firstName);
+      expect(
+        screen.getByLabelText(new RegExp('last name', 'i')),
+      ).toHaveDisplayValue(resume.profile.lastName);
+      expect(
+        screen.getAllByText(new RegExp(resume.profile.firstName, 'i')).length,
+      ).toBeTruthy();
+      expect(
+        screen.getAllByText(new RegExp(resume.profile.lastName, 'i')).length,
+      ).toBeTruthy();
+    });
+  });
+
+  describe('updates data', () => {
+    it('when input value is changed', async () => {
+      const input = screen.getByLabelText(new RegExp('address line 1', 'i'));
+      const newInputValue = 'test street 123';
+      const now = new Date().getTime();
+
+      fireEvent.change(input, { target: { value: newInputValue } });
+
+      expect(input.value).toBe(newInputValue);
+
+      await waitFor(() => mockUpdateFunction.mock.calls[0][0], {
+        timeout: DebounceWaitTime,
+      });
+      expect(mockUpdateFunction).toHaveBeenCalledTimes(1);
+      const mockUpdateFunctionCallArgument =
+        mockUpdateFunction.mock.calls[0][0];
+      expect(mockUpdateFunctionCallArgument.id).toBe(resume.id);
+      expect(mockUpdateFunctionCallArgument.profile.address.line1).toBe(
+        newInputValue,
+      );
+      expect(mockUpdateFunctionCallArgument.updatedAt).toBeGreaterThanOrEqual(
+        now,
+      );
+    });
+  });
+
+  describe('settings', () => {
+    it('allow to change the language', async () => {
+      const languageSelectElement = screen.getByLabelText('Language');
+      const newLanguage = 'it';
+      const now = new Date().getTime();
+
+      fireEvent.change(languageSelectElement, {
+        target: { value: newLanguage },
+      });
+
+      expect(languageSelectElement).toHaveValue(newLanguage);
+
+      expect(
+        screen.queryByLabelText(new RegExp('date of birth', 'i')),
+      ).toBeNull();
+      expect(
+        screen.getByLabelText(new RegExp('data di nascita', 'i')),
+      ).toBeInTheDocument();
+
+      await waitFor(() => mockUpdateFunction.mock.calls[0][0], {
+        timeout: DebounceWaitTime,
+      });
+      expect(mockUpdateFunction).toHaveBeenCalledTimes(1);
+      const mockUpdateFunctionCallArgument =
+        mockUpdateFunction.mock.calls[0][0];
+      expect(mockUpdateFunctionCallArgument.id).toBe(resume.id);
+      expect(mockUpdateFunctionCallArgument.metadata.language).toBe(
+        newLanguage,
+      );
+      expect(mockUpdateFunctionCallArgument.updatedAt).toBeGreaterThanOrEqual(
+        now,
+      );
+    });
+  });
+});

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

@@ -0,0 +1,76 @@
+import React from 'react';
+import { act, render, screen, waitFor } from '@testing-library/react';
+
+import FirebaseStub, { DatabaseConstants } from 'gatsby-plugin-firebase';
+
+import '../../../i18n/index';
+import '../../../utils/dayjs';
+import { SettingsProvider } from '../../../contexts/SettingsContext';
+import { ModalProvider } from '../../../contexts/ModalContext';
+import { UserProvider } from '../../../contexts/UserContext';
+import { DatabaseProvider } from '../../../contexts/DatabaseContext';
+import { ResumeProvider } from '../../../contexts/ResumeContext';
+import { StorageProvider } from '../../../contexts/StorageContext';
+import Dashboard from '../dashboard';
+
+describe('Dashboard', () => {
+  let resumes = null;
+  const user = DatabaseConstants.user1;
+
+  beforeEach(async () => {
+    FirebaseStub.database().initializeData();
+
+    resumes = (
+      await FirebaseStub.database()
+        .ref(DatabaseConstants.resumesPath)
+        .orderByChild('user')
+        .equalTo(user.uid)
+        .once('value')
+    ).val();
+
+    render(
+      <SettingsProvider>
+        <ModalProvider>
+          <UserProvider>
+            <DatabaseProvider>
+              <ResumeProvider>
+                <StorageProvider>
+                  <Dashboard user={user} />
+                </StorageProvider>
+              </ResumeProvider>
+            </DatabaseProvider>
+          </UserProvider>
+        </ModalProvider>
+      </SettingsProvider>,
+    );
+
+    await act(async () => {
+      await FirebaseStub.auth().signInAnonymously();
+    });
+
+    await waitFor(() => screen.getByText('Create Resume'));
+  });
+
+  describe('renders', () => {
+    it('document title', async () => {
+      expect(document.title).toEqual('Dashboard | Reactive Resume');
+    });
+
+    it('create resume', async () => {
+      expect(screen.getByText('Create Resume')).toBeInTheDocument();
+    });
+
+    it('preview of user resumes', async () => {
+      expect(Object.keys(resumes)).toHaveLength(2);
+
+      expect(Object.values(resumes)[0].user).toEqual(user.uid);
+      expect(
+        screen.getByText(Object.values(resumes)[0].name),
+      ).toBeInTheDocument();
+      expect(Object.values(resumes)[1].user).toEqual(user.uid);
+      expect(
+        screen.getByText(Object.values(resumes)[1].name),
+      ).toBeInTheDocument();
+    });
+  });
+});

src/templates/__tests__/Castform.test.js

@@ -0,0 +1,52 @@
+import React from 'react';
+import { render, screen } from '@testing-library/react';
+
+import FirebaseStub, { DatabaseConstants } from 'gatsby-plugin-firebase';
+
+import '../../i18n/index';
+import Castform from '../Castform';
+
+describe('Castform', () => {
+  let resume = {};
+
+  beforeEach(async () => {
+    FirebaseStub.database().initializeData();
+
+    const resumeId = DatabaseConstants.initialStateResumeId;
+    resume = (
+      await FirebaseStub.database()
+        .ref(`${DatabaseConstants.resumesPath}/${resumeId}`)
+        .once('value')
+    ).val();
+  });
+
+  it('renders correctly', () => {
+    const { container } = render(<Castform data={resume} />);
+
+    expect(container).toBeTruthy();
+    expect(container).toBeInTheDocument();
+  });
+
+  describe('date of birth', () => {
+    const birthDateLabelMatcher = /Date of birth/i;
+
+    it('is not shown if not provided', () => {
+      render(<Castform data={resume} />);
+
+      expect(screen.queryByText(birthDateLabelMatcher)).toBeNull();
+    });
+
+    it('is shown if provided', () => {
+      const birthDate = new Date(1990, 0, 20);
+      const birthDateFormatted = '20 January 1990';
+      resume.profile.birthDate = birthDate;
+
+      render(<Castform data={resume} />);
+
+      expect(screen.getByText(birthDateLabelMatcher)).toBeTruthy();
+      expect(screen.getByText(birthDateLabelMatcher)).toBeInTheDocument();
+      expect(screen.getByText(birthDateFormatted)).toBeTruthy();
+      expect(screen.getByText(birthDateFormatted)).toBeInTheDocument();
+    });
+  });
+});