use guard else

Author: masashi-sutou

StudyplusSDK/Studyplus.swift

@@ -183,7 +183,7 @@ final public class Studyplus {
     /// - Returns: If the url is supported by StudyplusSDK, returns true. The valid URL has a __[studyplus-{consumerKey}]__ scheme, and right pathComponents and host. 渡されたurlがStudyplusSDKで対応すべきURL（スキームが __[studyplus-{consumerKey}]__ であり、host/pathComponentsが想定内であるもの）であれば true、それ以外は false を返します。
     public func handle(appDelegateUrl: URL) -> Bool {
 
-        if !isAcceptableURL(url: appDelegateUrl) {
+        guard isAcceptableURL(url: appDelegateUrl) else {
             delegate?.studyplusDidFailToLogin(error: .unknownUrl(appDelegateUrl))
             return false
         }
@@ -292,14 +292,10 @@ final public class Studyplus {
     private func isAcceptableURL(url: URL) -> Bool {
 
         guard let host = url.host else { return false }
-        if host != "auth-result" && host != "login-result" {
-            return false
-        }
+        guard host == "auth-result" || host == "login-result" else { return false }
 
         guard let scheme = url.scheme else { return false }
-        if scheme != "studyplus-\(consumerKey)" {
-            return false
-        }
+        guard scheme == "studyplus-\(consumerKey)" else { return false }
 
         if url.pathComponents.isEmpty {
             return false

StudyplusSDK/StudyplusAPIRequest.swift

@@ -83,11 +83,23 @@ internal struct StudyplusAPIRequest {
 
             urlSession.finishTasksAndInvalidate()
 
-            if error == nil && response != nil {
-                if let httpResponse: HTTPURLResponse = response as? HTTPURLResponse {
-                    if httpResponse.statusCode == 200 || httpResponse.statusCode == 201 || httpResponse.statusCode == 202 {
-                        
-                        if let data = data {
+            guard error == nil && response != nil else {
+                failure(0, nil)
+                return
+            }
+            
+            guard let httpResponse: HTTPURLResponse = response as? HTTPURLResponse else {
+                failure(0, nil)
+                return
+            }
+            
+            switch httpResponse.statusCode {
+            case 200, 201, 202:
+                guard let data = data else {
+                    failure(0, nil)
+                    return
+                }
+                
                 do {
                     let jsonObject = try JSONSerialization.jsonObject(with: data, options: .allowFragments)
                     success(jsonObject as? [String : Any])
@@ -98,17 +110,18 @@ internal struct StudyplusAPIRequest {
                     #endif
                     failure(httpResponse.statusCode, ["message": error.localizedDescription])
                 }
-                        }
-                        
-                    } else if httpResponse.statusCode == 204 {
+            case 204:
                 success(nil)
                 return
-                        
-                    } else {
+            default:
                 #if DEBUG
                     print("-- StudyplusAPIRequest Path: \(url.absoluteString), Method: \(method), StatusCode: \(httpResponse.statusCode) --")
                 #endif
-                        if let data = data {
+                guard let data = data else {
+                    failure(0, nil)
+                    return
+                }
+                
                 do {
                     let jsonObject = try JSONSerialization.jsonObject(with: data, options: .allowFragments)
                     failure(httpResponse.statusCode, jsonObject as? [String: Any])
@@ -119,11 +132,6 @@ internal struct StudyplusAPIRequest {
                 }
             }
         }
-                }
-            }
-            
-            failure(0, nil)
-        }
 
         #if DEBUG
             NSLog("StudyplusAPIRequest path:%@ method:%@", url.absoluteString, method)

StudyplusSDK/StudyplusRecordAmount.swift

@@ -64,7 +64,7 @@ public struct StudyplusRecordAmount {
     /// - Parameter range: Starting point and ending point of learning amount. 学習量の起点と終点。
     public init?(range: (from: UInt, to: UInt)) {
 
-        if range.from > range.to {
+        guard range.from <= range.to else {
            return nil
         }