feat(auth): Added APIs for generating email sign-in links (#165)

Author: hiranya911

FirebaseAdmin/FirebaseAdmin.Tests/Auth/EmailActionRequestTest.cs

@@ -105,6 +105,11 @@ public void NoEmail()
                 async () => await auth.GeneratePasswordResetLinkAsync(null));
             Assert.ThrowsAsync<ArgumentException>(
                 async () => await auth.GeneratePasswordResetLinkAsync(string.Empty));
+
+            Assert.ThrowsAsync<ArgumentException>(
+                async () => await auth.GenerateSignInWithEmailLinkAsync(null, ActionCodeSettings));
+            Assert.ThrowsAsync<ArgumentException>(
+                async () => await auth.GenerateSignInWithEmailLinkAsync(string.Empty, ActionCodeSettings));
         }
 
         [Theory]
@@ -120,6 +125,9 @@ public void InvalidActionCodeSettings(ActionCodeSettings settings)
 
             Assert.ThrowsAsync<ArgumentException>(
                 async () => await auth.GeneratePasswordResetLinkAsync(email, settings));
+
+            Assert.ThrowsAsync<ArgumentException>(
+                async () => await auth.GenerateSignInWithEmailLinkAsync(email, settings));
         }
 
         [Fact]
@@ -254,6 +262,65 @@ public async Task PasswordResetLinkUnexpectedResponse()
             Assert.Null(exception.InnerException);
         }
 
+        [Fact]
+        public void SignInWithEmailLinkNoSettings()
+        {
+            var handler = new MockMessageHandler() { Response = GenerateEmailLinkResponse };
+            var auth = this.CreateFirebaseAuth(handler);
+            var email = "[email protected]";
+
+            Assert.ThrowsAsync<ArgumentException>(
+                async () => await auth.GenerateSignInWithEmailLinkAsync(email, null));
+        }
+
+        [Fact]
+        public async Task SignInWithEmailLink()
+        {
+            var handler = new MockMessageHandler() { Response = GenerateEmailLinkResponse };
+            var auth = this.CreateFirebaseAuth(handler);
+
+            var link = await auth.GenerateSignInWithEmailLinkAsync(
+                "[email protected]", ActionCodeSettings);
+
+            Assert.Equal("https://mock-oob-link.for.auth.tests", link);
+
+            var request = NewtonsoftJsonSerializer.Instance.Deserialize<Dictionary<string, object>>(
+                handler.LastRequestBody);
+            Assert.Equal(10, request.Count);
+            Assert.Equal("[email protected]", request["email"]);
+            Assert.Equal("EMAIL_SIGNIN", request["requestType"]);
+            Assert.True((bool)request["returnOobLink"]);
+
+            Assert.Equal(ActionCodeSettings.Url, request["continueUrl"]);
+            Assert.True((bool)request["canHandleCodeInApp"]);
+            Assert.Equal(ActionCodeSettings.DynamicLinkDomain, request["dynamicLinkDomain"]);
+            Assert.Equal(ActionCodeSettings.IosBundleId, request["iOSBundleId"]);
+            Assert.Equal(ActionCodeSettings.AndroidPackageName, request["androidPackageName"]);
+            Assert.Equal(
+                ActionCodeSettings.AndroidMinimumVersion, request["androidMinimumVersion"]);
+            Assert.True((bool)request["androidInstallApp"]);
+            this.AssertRequest(handler.Requests[0]);
+        }
+
+        [Fact]
+        public async Task SignInWithEmailLinkUnexpectedResponse()
+        {
+            var handler = new MockMessageHandler() { Response = "{}" };
+            var auth = this.CreateFirebaseAuth(handler);
+
+            var exception = await Assert.ThrowsAsync<FirebaseAuthException>(
+                async () => await auth.GenerateSignInWithEmailLinkAsync(
+                    "[email protected]", ActionCodeSettings));
+
+            Assert.Equal(ErrorCode.Unknown, exception.ErrorCode);
+            Assert.Equal(AuthErrorCode.UnexpectedResponse, exception.AuthErrorCode);
+            Assert.Equal(
+                $"Failed to generate email action link for: [email protected]",
+                exception.Message);
+            Assert.NotNull(exception.HttpResponse);
+            Assert.Null(exception.InnerException);
+        }
+
         private FirebaseAuth CreateFirebaseAuth(HttpMessageHandler handler)
         {
             var userManager = new FirebaseUserManager(new FirebaseUserManager.Args

FirebaseAdmin/FirebaseAdmin/Auth/EmailActionLinkRequest.cs

@@ -21,6 +21,7 @@ internal sealed class EmailActionLinkRequest
     {
         private const string VerifyEmail = "VERIFY_EMAIL";
         private const string PasswordReset = "PASSWORD_RESET";
+        private const string EmailSignIn = "EMAIL_SIGNIN";
 
         private EmailActionLinkRequest(string type, string email, ActionCodeSettings settings)
         {
@@ -29,6 +30,12 @@ private EmailActionLinkRequest(string type, string email, ActionCodeSettings set
                 throw new ArgumentException("Email cannot be null or empty.");
             }
 
+            if (type == EmailSignIn && settings == null)
+            {
+                throw new ArgumentNullException(
+                    "ActionCodeSettings must not be null when generating sign in links");
+            }
+
             this.RequestType = type;
             this.Email = email;
             if (settings != null)
@@ -87,6 +94,12 @@ internal static EmailActionLinkRequest PasswordResetLinkRequest(
             return new EmailActionLinkRequest(PasswordReset, email, settings);
         }
 
+        internal static EmailActionLinkRequest EmailSignInLinkRequest(
+            string email, ActionCodeSettings settings)
+        {
+            return new EmailActionLinkRequest(EmailSignIn, email, settings);
+        }
+
         private void ValidateSettings()
         {
             if (string.IsNullOrEmpty(this.Url))

FirebaseAdmin/FirebaseAdmin/Auth/FirebaseAuth.cs

@@ -654,6 +654,44 @@ public async Task<string> GeneratePasswordResetLinkAsync(
                 .ConfigureAwait(false);
         }
 
+        /// <summary>
+        /// Generates the out-of-band email action link for email link sign-in flows for the
+        /// specified email address.
+        /// </summary>
+        /// <exception cref="FirebaseAuthException">If an error occurs while generating the link.</exception>
+        /// <param name="email">The email of the user signing in.</param>
+        /// <param name="settings">The action code settings object that defines whether
+        /// the link is to be handled by a mobile app and the additional state information to be
+        /// passed in the deep link.</param>
+        /// <returns>A task that completes with the email sign in link.</returns>
+        public async Task<string> GenerateSignInWithEmailLinkAsync(
+            string email, ActionCodeSettings settings)
+        {
+            return await this.GenerateSignInWithEmailLinkAsync(email, settings, default(CancellationToken))
+                .ConfigureAwait(false);
+        }
+
+        /// <summary>
+        /// Generates the out-of-band email action link for email link sign-in flows for the
+        /// specified email address.
+        /// </summary>
+        /// <exception cref="FirebaseAuthException">If an error occurs while generating the link.</exception>
+        /// <param name="email">The email of the user signing in.</param>
+        /// <param name="settings">The action code settings object that defines whether
+        /// the link is to be handled by a mobile app and the additional state information to be
+        /// passed in the deep link.</param>
+        /// <param name="cancellationToken">A cancellation token to monitor the asynchronous
+        /// operation.</param>
+        /// <returns>A task that completes with the email sign in link.</returns>
+        public async Task<string> GenerateSignInWithEmailLinkAsync(
+            string email, ActionCodeSettings settings, CancellationToken cancellationToken)
+        {
+            var userManager = this.IfNotDeleted(() => this.userManager.Value);
+            var request = EmailActionLinkRequest.EmailSignInLinkRequest(email, settings);
+            return await userManager.GenerateEmailActionLinkAsync(request, cancellationToken)
+                .ConfigureAwait(false);
+        }
+
         /// <summary>
         /// Deletes this <see cref="FirebaseAuth"/> service instance.
         /// </summary>