Minor refactoring

SignalServiceKit/src/Loki/API/HTTP/HTTP.swift

@@ -41,53 +41,53 @@ internal enum HTTP {
 
     // MARK: Main
     internal static func execute(_ verb: Verb, _ url: String, parameters: JSON? = nil, timeout: TimeInterval = HTTP.timeout) -> Promise<JSON> {
-        return Promise<JSON> { seal in
-            var request = URLRequest(url: URL(string: url)!)
-            request.httpMethod = verb.rawValue
-            if let parameters = parameters {
-                do {
-                    guard JSONSerialization.isValidJSONObject(parameters) else { return seal.reject(Error.invalidJSON) }
-                    request.httpBody = try JSONSerialization.data(withJSONObject: parameters, options: [])
-                } catch (let error) {
-                    return seal.reject(error)
-                }
+        var request = URLRequest(url: URL(string: url)!)
+        request.httpMethod = verb.rawValue
+        if let parameters = parameters {
+            do {
+                guard JSONSerialization.isValidJSONObject(parameters) else { return Promise(error: Error.invalidJSON) }
+                request.httpBody = try JSONSerialization.data(withJSONObject: parameters, options: [])
+            } catch (let error) {
+                return Promise(error: error)
             }
-            request.timeoutInterval = timeout
-            let task = urlSession.dataTask(with: request) { data, response, error in
-                guard let data = data, let response = response as? HTTPURLResponse else {
-                    if let error = error {
-                        print("[Loki] \(verb.rawValue) request to \(url) failed due to error: \(error).")
-                    } else {
-                        print("[Loki] \(verb.rawValue) request to \(url) failed.")
-                    }
-                    // Override the actual error so that we can correctly catch failed requests in sendOnionRequest(invoking:on:with:)
-                    return seal.reject(Error.httpRequestFailed(statusCode: 0, json: nil))
-                }
+        }
+        request.timeoutInterval = timeout
+        let (promise, seal) = Promise<JSON>.pending()
+        let task = urlSession.dataTask(with: request) { data, response, error in
+            guard let data = data, let response = response as? HTTPURLResponse else {
                 if let error = error {
                     print("[Loki] \(verb.rawValue) request to \(url) failed due to error: \(error).")
-                    // Override the actual error so that we can correctly catch failed requests in sendOnionRequest(invoking:on:with:)
-                    return seal.reject(Error.httpRequestFailed(statusCode: 0, json: nil))
-                }
-                let statusCode = UInt(response.statusCode)
-                var json: JSON? = nil
-                if let j = try? JSONSerialization.jsonObject(with: data, options: []) as? JSON {
-                    json = j
-                } else if let result = String(data: data, encoding: .utf8) {
-                    json = [ "result" : result ]
-                }
-                guard 200...299 ~= statusCode else {
-                    let jsonDescription = json?.prettifiedDescription ?? "no debugging info provided"
-                    print("[Loki] \(verb.rawValue) request to \(url) failed with status code: \(statusCode) (\(jsonDescription)).")
-                    return seal.reject(Error.httpRequestFailed(statusCode: statusCode, json: json))
-                }
-                if let json = json {
-                    seal.fulfill(json)
                 } else {
-                    print("[Loki] Couldn't parse JSON returned by \(verb.rawValue) request to \(url).")
-                    return seal.reject(Error.invalidJSON)
+                    print("[Loki] \(verb.rawValue) request to \(url) failed.")
                 }
+                // Override the actual error so that we can correctly catch failed requests in sendOnionRequest(invoking:on:with:)
+                return seal.reject(Error.httpRequestFailed(statusCode: 0, json: nil))
+            }
+            if let error = error {
+                print("[Loki] \(verb.rawValue) request to \(url) failed due to error: \(error).")
+                // Override the actual error so that we can correctly catch failed requests in sendOnionRequest(invoking:on:with:)
+                return seal.reject(Error.httpRequestFailed(statusCode: 0, json: nil))
+            }
+            let statusCode = UInt(response.statusCode)
+            var json: JSON? = nil
+            if let j = try? JSONSerialization.jsonObject(with: data, options: []) as? JSON {
+                json = j
+            } else if let result = String(data: data, encoding: .utf8) {
+                json = [ "result" : result ]
+            }
+            guard 200...299 ~= statusCode else {
+                let jsonDescription = json?.prettifiedDescription ?? "no debugging info provided"
+                print("[Loki] \(verb.rawValue) request to \(url) failed with status code: \(statusCode) (\(jsonDescription)).")
+                return seal.reject(Error.httpRequestFailed(statusCode: statusCode, json: json))
+            }
+            if let json = json {
+                seal.fulfill(json)
+            } else {
+                print("[Loki] Couldn't parse JSON returned by \(verb.rawValue) request to \(url).")
+                return seal.reject(Error.invalidJSON)
             }
-            task.resume()
         }
+        task.resume()
+        return promise
     }
 }