refactor(auth): enable multiple social providers (#25)

auth/auth.test.ts

@@ -21,6 +21,7 @@ describe("#createUserWithEmailAndPassword()", () => {
     expect(auth.store.add).toHaveBeenCalledWith({
       email: "foo@bar.com",
       password: "password",
+      providerId: firebase.auth.EmailAuthProvider.PROVIDER_ID,
     });
   });
 
@@ -54,7 +55,7 @@ describe("#onAuthStateChange()", () => {
     expect(listener).toHaveBeenCalledWith(credential.user);
   });
 
-  it("doesn't invokes the listener after it's disposed", async () => {
+  it("doesn't invoke the listener after it's disposed", async () => {
     const auth = new MockAuth(app);
     const listener = jest.fn();
     const disposer = auth.onAuthStateChanged(listener);

auth/auth.ts

@@ -4,6 +4,7 @@ import { SocialSignInMock } from "./social-signin-mock";
 import { User } from "./user";
 import { UserStore } from "./user-store";
 import { AuthSettings } from "./auth-settings";
+import { UserCredential, UserCredentialOptions } from "./user-credential";
 
 export type AuthStateChangeListener = (user: firebase.User | null) => void;
 
@@ -13,7 +14,6 @@ export class MockAuth implements firebase.auth.Auth {
   public settings: firebase.auth.AuthSettings = new AuthSettings();
   public tenantId: string | null;
   public readonly store = new UserStore();
-  private readonly socialSignIns = new Set<SocialSignInMock>();
   private readonly authStateEvents = new Set<AuthStateChangeListener>();
 
   constructor(public readonly app: MockApp) {}
@@ -38,8 +38,9 @@ export class MockAuth implements firebase.auth.Auth {
       throw new Error("auth/email-already-in-use");
     }
 
-    const user = this.store.add({ email, password });
-    return this.signIn(user);
+    const { providerId } = new firebase.auth.EmailAuthProvider();
+    const user = this.store.add({ email, password, providerId });
+    return this.signIn(user, { isNewUser: true });
   }
 
   fetchProvidersForEmail(email: string): Promise<any> {
@@ -60,7 +61,7 @@ export class MockAuth implements firebase.auth.Auth {
 
   mockSocialSignIn(provider: firebase.auth.AuthProvider) {
     const mock = new SocialSignInMock(provider.providerId);
-    this.socialSignIns.add(mock);
+    this.store.addSocialMock(mock);
     return mock;
   }
 
@@ -105,19 +106,26 @@ export class MockAuth implements firebase.auth.Auth {
 
   private signIn(
     user: User,
-    additionalUserInfo: firebase.auth.AdditionalUserInfo | null = null
+    options: UserCredentialOptions
   ): Promise<firebase.auth.UserCredential> {
     this.currentUser = user;
     this.authStateEvents.forEach((listener) => {
       listener(user);
     });
 
-    return Promise.resolve<firebase.auth.UserCredential>({
-      user,
-      additionalUserInfo,
-      credential: null,
-      operationType: "signIn",
-    });
+    return Promise.resolve(new UserCredential(user, "signIn", options));
+  }
+
+  private async signInWithSocial(provider: firebase.auth.AuthProvider) {
+    const mockResponse = await this.store.consumeSocialMock(provider);
+    let user = this.store.findByProviderAndEmail(mockResponse.email, provider.providerId);
+    if (user) {
+      return this.signIn(user, { isNewUser: false });
+    }
+
+    // user didn't exist, so it's created and then signed in
+    user = this.store.add({ ...mockResponse, providerId: provider.providerId });
+    return this.signIn(user, { isNewUser: true });
   }
 
   signInAndRetrieveDataWithCredential(credential: firebase.auth.AuthCredential): Promise<any> {
@@ -126,11 +134,11 @@ export class MockAuth implements firebase.auth.Auth {
 
   signInAnonymously(): Promise<firebase.auth.UserCredential> {
     if (this.currentUser && this.currentUser.isAnonymous) {
-      return this.signIn(this.currentUser);
+      return this.signIn(this.currentUser, { isNewUser: false });
     }
 
     const user = this.store.add({ isAnonymous: true });
-    return this.signIn(user);
+    return this.signIn(user, { isNewUser: true });
   }
 
   signInWithCredential(credential: firebase.auth.AuthCredential): Promise<any> {
@@ -152,7 +160,7 @@ export class MockAuth implements firebase.auth.Auth {
       return Promise.reject(new Error("auth/wrong-password"));
     }
 
-    return this.signIn(user);
+    return this.signIn(user, { isNewUser: false });
   }
 
   signInWithEmailLink(
@@ -169,42 +177,8 @@ export class MockAuth implements firebase.auth.Auth {
     throw new Error("Method not implemented.");
   }
 
-  async signInWithPopup(
-    provider: firebase.auth.AuthProvider
-  ): Promise<firebase.auth.UserCredential> {
-    const mock = Array.from(this.socialSignIns.values()).find(
-      (mock) => mock.type === provider.providerId
-    );
-
-    if (!mock) {
-      throw new Error("No mock response set.");
-    }
-
-    // Mock is used, then it must go
-    this.socialSignIns.delete(mock);
-
-    const data = await mock.response;
-    let user = this.store.findByEmail(data.email);
-    if (user) {
-      if (user.providerId !== provider.providerId) {
-        throw new Error("auth/account-exists-with-different-credential");
-      }
-
-      return this.signIn(user, {
-        isNewUser: false,
-        providerId: provider.providerId,
-        profile: null,
-        username: data.email,
-      });
-    }
-
-    user = this.store.add({ ...data, providerId: provider.providerId });
-    return this.signIn(user, {
-      isNewUser: true,
-      providerId: provider.providerId,
-      profile: null,
-      username: data.email,
-    });
+  signInWithPopup(provider: firebase.auth.AuthProvider): Promise<firebase.auth.UserCredential> {
+    return this.signInWithSocial(provider);
   }
 
   signInWithRedirect(provider: firebase.auth.AuthProvider): Promise<void> {

auth/user-credential.ts

@@ -0,0 +1,26 @@
+import { User } from "./user";
+
+export interface UserCredentialOptions {
+  isNewUser: boolean;
+}
+
+export class UserCredential implements firebase.auth.UserCredential {
+  readonly additionalUserInfo: firebase.auth.AdditionalUserInfo | null = null;
+  readonly credential = null;
+
+  constructor(
+    readonly user: User,
+    readonly operationType: "signIn" | "link" | "reauthenticate",
+    { isNewUser }: UserCredentialOptions
+  ) {
+    if (!user.isAnonymous) {
+      this.additionalUserInfo = {
+        isNewUser,
+        profile: null,
+        // providerId should be at the right value in the user object already.
+        providerId: user.providerId,
+        username: user.email,
+      };
+    }
+  }
+}

auth/user-store.ts

@@ -1,27 +1,75 @@
-import { User, UserSchema } from "./user";
+import { User, UserSchema, UserInfo } from "./user";
+import { SocialSignInMock } from "./social-signin-mock";
 
 export class UserStore {
   private nextId = 0;
-  private idStore = new Map<string, UserSchema>();
-  private emailStore = new Map<string, UserSchema>();
+  private store = new Map<string, UserSchema>();
+  private readonly socialMocks: SocialSignInMock[] = [];
 
+  /**
+   * Adds a user to this store with the given data.
+   * The new user is assigned a new ID and is returned.
+   */
   add(data: Partial<UserSchema>): User {
     const uid = ++this.nextId + "";
-    const user = new User({ ...data, uid }, this);
+    const user = new User(
+      {
+        ...data,
+        // If the user is being created with a provider ID, then its data is coming from that provider.
+        providerData: data.providerId ? [new UserInfo(uid, data.providerId, data)] : [],
+        uid,
+      },
+      this
+    );
 
     const schema = user.toJSON() as UserSchema;
-    this.idStore.set(schema.uid, schema);
-    schema.email && this.emailStore.set(schema.email, schema);
+    this.store.set(schema.uid, schema);
     return user;
   }
 
+  addSocialMock(mock: SocialSignInMock) {
+    this.socialMocks.push(mock);
+  }
+
+  /**
+   * Finds the mock response for a given AuthProvider, removes it from the list of mocks
+   * and returns its response.
+   *
+   * If a mock for that AuthProvider is not set, then this method throws.
+   */
+  consumeSocialMock(provider: firebase.auth.AuthProvider) {
+    const index = this.socialMocks.findIndex((mock) => mock.type === provider.providerId);
+    if (index === -1) {
+      throw new Error("No mock response set.");
+    }
+
+    // Mock is used, then it must go
+    const mock = this.socialMocks[index];
+    this.socialMocks.splice(index, 1);
+
+    return mock.response;
+  }
+
   findByEmail(email: string): User | undefined {
-    const schema = this.emailStore.get(email);
-    return schema ? new User(schema, this) : undefined;
+    const schema = [...this.store.values()].find((user) => user.email === email);
+    return schema && new User(schema, this);
+  }
+
+  findByProviderAndEmail(email: string, providerId: string): User | undefined {
+    const user = this.findByEmail(email);
+    if (!user) {
+      return undefined;
+    }
+
+    if (user.providerData.some((info) => info.providerId === providerId)) {
+      return new User({ ...user.toJSON(), providerId }, this);
+    }
+
+    throw new Error("auth/account-exists-with-different-credential");
   }
 
   update(id: string, data: Partial<UserSchema>) {
-    const schema = this.idStore.get(id);
+    const schema = this.store.get(id);
     if (!schema) {
       return;
     }

auth/user.ts

@@ -7,7 +7,7 @@ export interface UserSchema {
   metadata: firebase.auth.UserMetadata;
   password?: string;
   phoneNumber: string | null;
-  providerData: (firebase.UserInfo | null)[];
+  providerData: UserInfo[];
   refreshToken: string;
   displayName: string | null;
   email: string | null;
@@ -17,7 +17,26 @@ export interface UserSchema {
   tenantId: string | null;
 }
 
+export class UserInfo implements firebase.UserInfo {
+  readonly displayName: string | null;
+  readonly email: string | null;
+  readonly phoneNumber: string | null;
+  readonly photoURL: string | null;
+
+  constructor(
+    readonly uid: string,
+    readonly providerId: string,
+    rest: Partial<Omit<firebase.UserInfo, "uid" | "providerId">>
+  ) {
+    this.displayName = rest.displayName ?? null;
+    this.email = rest.email ?? null;
+    this.phoneNumber = rest.phoneNumber ?? null;
+    this.photoURL = rest.photoURL ?? null;
+  }
+}
+
 export class User implements firebase.User, UserSchema {
+  readonly uid: string;
   displayName: string | null;
   email: string | null;
   emailVerified: boolean;
@@ -26,11 +45,10 @@ export class User implements firebase.User, UserSchema {
   password?: string;
   phoneNumber: string | null;
   photoURL: string | null;
-  providerData: (firebase.UserInfo | null)[];
+  providerData: UserInfo[];
   providerId: string;
   refreshToken: string;
   tenantId: string | null;
-  uid: string;
   multiFactor: firebase.User.MultiFactorUser;
 
   constructor(data: Partial<UserSchema>, private readonly store: UserStore) {