An easy way to fix your two-closure Swift indentation

gistfile1.txt

// A beautiful two-closure method.
signInUser("fer", pass: "quetzalmx") { User in
    // Success
    print(User)
}.onFailure { error in
    // Failure
    print(error)
}

// Calls a function that returns an object which can optionally fail.
func signInUser(username: String, pass: String, successBlock: User -> ()) -> QuetzalRequest {
    let request = // Create your Alamofire.Request
    return QuetzalRequest(withRequest: request) { response, data in
        // Do something with 100% valid data and response.
        // If anything happens just throw.
        guard let validUser = transform(data) else {
            throw MyTransformError
        }

        successBlock(validUser)
    }
}

// Our wrapper object.
// It's basically a wrapper that holds general logic for all our calls: 
// check valid httpResponse and check valid data
// if neither is good, call your error closure.
class QuetzalRequest {
    let request: Alamofire.Request
    private var errorClosure: NSError -> () = { error in }

    init(withRequest request: Alamofire.Request, onSuccess: (response: NSHTTPURLResponse, data: NSData) throws -> ())
    {
        self.request = request
        self.request.validate().responseData { response in
            if let error = response.result.error {
                self.errorClosure(error)
            }

            guard let receivedResponse = response.response else {
                self.errorClosure(MyCustomResponseError)
            }
 
            guard let receivedData = response.data else {
                self.errorClosure(MyCustomNoDataError)
            }
 
            do {
                try onSuccess()
            } catch let error as NSError {
                self.errorClosure(error)
            }
    }

    func onFailure(errorClosure: (NSError -> ())) {
        self.errorClosure = errorClosure
    }
}