add authenticate method

auth0-lock.js

@@ -21,6 +21,14 @@ class Auth0Lock {
     }
     LockModule.show(options, callback);
   }
+
+  authenticate(connectionName, options, callback) {
+    LockModule.init(this.lockOptions);
+    if (this.nativeIntegrations) {
+      LockModule.nativeIntegrations(this.nativeIntegrations);
+    }
+    LockModule.authenticate(connectionName, options, callback);
+  }
 }
 
-module.exports = Auth0Lock;
+module.exports = Auth0Lock;

objc/A0LockReactModule.m

@@ -91,4 +91,10 @@ @implementation A0LockReactModule
     });
 }
 
-@end
+RCT_EXPORT_METHOD(authenticate:(NSString *)connectionName options:(NSDictionary *)options callback:(RCTResponseSenderBlock)callback) {
+    dispatch_async(dispatch_get_main_queue(), ^{
+        [[A0LockReact sharedInstance] authenticateWithConnectionName:connectionName options:options callback:callback];
+    });
+}
+
+@end

objc/core/A0LockReact.h

@@ -31,6 +31,8 @@ typedef void(^A0LockCallback)(NSArray *parameters);
 
 - (void)showWithOptions:(NSDictionary *)options callback:(A0LockCallback)callback;
 
+- (void)authenticateWithConnectionName:(NSString *)connectionName options:(NSDictionary *)options callback:(A0LockCallback)callback;
+
 - (void)configureLockFromBundle;
 
 - (void)configureLockWithClientId:(NSString *)clientId domain:(NSString *)domain;

objc/core/A0LockReact.m

@@ -117,6 +117,25 @@ - (void)showWithOptions:(NSDictionary *)options callback:(A0LockCallback)callbac
     }
 }
 
+- (void)authenticateWithConnectionName:(NSString *)connectionName options:(NSDictionary *)options callback:(A0LockCallback)callback {
+    A0IdentityProviderAuthenticator *authenticator = [self.lock identityProviderAuthenticator];
+    void(^success)(A0UserProfile *, A0Token *) = ^(A0UserProfile *profile, A0Token *token) {
+    if (profile && token) {
+        NSDictionary *profileDict = [profile asDictionary];
+        NSDictionary *tokenDict = [token asDictionary];
+        callback(@[[NSNull null], profileDict, tokenDict]);
+    } else {
+        callback(@[@"Unexpected null value in profile or token"]);
+    }
+    };
+    void(^failure)(NSError *) = ^(NSError *error) {
+        callback(@[[error localizedDescription]]);
+    };
+
+    A0AuthParameters* parameters = [A0AuthParameters newWithDictionary:options];
+    [authenticator authenticateWithConnectionName:connectionName parameters:parameters success:success failure:failure];
+}
+
 - (A0AuthParameters *)authenticationParametersFromOptions:(NSDictionary *)options {
     NSDictionary *jsonParameters = options[@"authParams"];
     if (jsonParameters.count == 0) {