Add email link sign in bindings (#261)

Author: Giovanni Terlingen

packages/firebase-dart/CHANGELOG.md

@@ -2,6 +2,7 @@
 
 - **BREAKING** renamed `AuthCredential` into `OAuthCredential` to align with JS API
 - Added `idToken`, `accessToken` and `secret` to `OAuthCredential`
+- Added support for Email Link authentication
 
 ## 6.0.0
 

packages/firebase-dart/lib/src/auth.dart

@@ -370,6 +370,20 @@ class Auth extends JsObjectWrapper<AuthJsImpl> {
       handleThenable(jsObject.getRedirectResult())
           .then((u) => UserCredential.fromJsObject(u));
 
+  /// Sends a sign-in email link to the user with the specified email.
+  ///
+  /// The sign-in operation has to always be completed in the app unlike other out
+  /// of band email actions (password reset and email verifications). This is
+  /// because, at the end of the flow, the user is expected to be signed in and
+  /// their Auth state persisted within the app.
+  ///
+  /// To complete sign in with the email link, call
+  /// [Auth.signInWithEmailLink] with the email address and
+  /// the email link supplied in the email sent to the user.
+  Future sendSignInLinkToEmail(String email,
+          [ActionCodeSettings actionCodeSettings]) =>
+      handleThenable(jsObject.sendSignInLinkToEmail(email, actionCodeSettings));
+
   /// Sends a password reset e-mail to the given [email].
   /// To confirm password reset, use the [Auth.confirmPasswordReset].
   ///
@@ -467,6 +481,11 @@ class Auth extends JsObjectWrapper<AuthJsImpl> {
       handleThenable(jsObject.signInWithEmailAndPassword(email, password))
           .then((u) => UserCredential.fromJsObject(u));
 
+  /// Signs in using [email] and [emailLink] link.
+  Future<UserCredential> signInWithEmailLink(String email, String emailLink) =>
+      handleThenable(jsObject.signInWithEmailLink(email, emailLink))
+          .then((u) => UserCredential.fromJsObject(u));
+
   /// Asynchronously signs in using a phone number in E.164 format
   /// (e.g. +16505550101).
   ///

packages/firebase-dart/lib/src/interop/auth_interop.dart

@@ -29,6 +29,8 @@ abstract class AuthJsImpl {
       [Func1 opt_error, Func0 opt_completed]);
   external Func0 onIdTokenChanged(nextOrObserver,
       [Func1 opt_error, Func0 opt_completed]);
+  external PromiseJsImpl sendSignInLinkToEmail(String email,
+      [ActionCodeSettings actionCodeSettings]);
   external PromiseJsImpl sendPasswordResetEmail(String email,
       [ActionCodeSettings actionCodeSettings]);
   external PromiseJsImpl setPersistence(String persistence);
@@ -42,6 +44,8 @@ abstract class AuthJsImpl {
       signInAndRetrieveDataWithCustomToken(String token);
   external PromiseJsImpl<UserCredentialJsImpl> signInWithEmailAndPassword(
       String email, String password);
+  external PromiseJsImpl<UserCredentialJsImpl> signInWithEmailLink(
+      String email, String emailLink);
   external PromiseJsImpl<ConfirmationResultJsImpl> signInWithPhoneNumber(
       String phoneNumber, ApplicationVerifierJsImpl applicationVerifier);
   external PromiseJsImpl<UserCredentialJsImpl> signInWithPopup(