added support for signInWithCustomToken on ios.

README.md

@@ -166,6 +166,20 @@ server.signInWithEmail('[email protected]', '123456')
   })
 ```
 
+#### signInWithCustomToken()
+
+To sign a user using a self-signed custom token, use the `signInWithCustomToken()` function. It accepts one parameter, the custom token:
+
+```javascript
+server.signInWithCustomToken(TOKEN)
+  .then((user) => {
+    console.log('User successfully logged in', user)
+  })
+  .catch((err) => {
+    console.error('User signin error', err);
+  })
+```
+
 #### signInWithProvider()
 
 We can use an external authentication provider, such as twitter/facebook for authentication. In order to use an external provider, we need to include another library to handle authentication.

firestack.ios.js

@@ -80,6 +80,15 @@ export default class Firestack {
     return promisify('signInWithProvider')(provider, authToken, authSecret);
   }
 
+  /**
+   * Sign the user in with a custom auth token
+   * @param  {string} customToken  A self-signed custom auth token.
+   * @return {Promise}             A promise resolved upon completion
+   */
+  signInWithCustomToken(customToken) {
+    return promisify('signInWithCustomToken')(customToken);
+  }
+
   /**
    * Reauthenticate a user with a third-party authentication provider
    * @param  {string} provider The provider name

ios/Firestack/Firestack.m

@@ -28,6 +28,27 @@ @implementation Firestack
   }
 }
 
+RCT_EXPORT_METHOD(signInWithCustomToken:
+                  (NSString *)customToken
+                  callback:(RCTResponseSenderBlock) callback)
+{
+    [[FIRAuth auth]
+      signInWithCustomToken:customToken
+      completion:^(FIRUser *user, NSError *error) {
+
+        if (user != nil) {
+          NSDictionary *userProps = [self userPropsFromFIRUser:user];
+          callback(@[[NSNull null], userProps]);
+        } else {
+          NSDictionary *err =
+          [self handleFirebaseError:@"signinError"
+                         error:error
+                      withUser:user];
+          callback(@[err]);
+        }
+    }];
+}
+
 RCT_EXPORT_METHOD(signInWithProvider:
                   (NSString *)provider
                   token:(NSString *)authToken