Some minor syntax improvement

Sources/Image/ImageProgressive.swift

@@ -90,13 +90,13 @@ final class ImageProgressiveProvider {
         let isFastest = option.isFastestScan
 
         func add(decode data: Data) {
-            queue.add(minimum: interval) { (completion) in
+            queue.add(minimum: interval) { completion in
                 guard self.isContinueClosure() else {
                     completion()
                     return
                 }
 
-                self.decoder.decode(data, with: callbacks) { (image) in
+                self.decoder.decode(data, with: callbacks) { image in
                     defer { completion() }
                     guard self.isContinueClosure() else { return }
                     guard self.isWait || !self.isFinishedClosure() else { return }
@@ -108,13 +108,11 @@ final class ImageProgressiveProvider {
         }
 
         if isFastest {
-            guard let data: Data = decoder.scanning(data) else { return }
-
+            guard let data = decoder.scanning(data) else { return }
             add(decode: data)
-
         } else {
-            let datas: [Data] = decoder.scanning(data)
-            for data in datas {
+            let allData: [Data] = decoder.scanning(data)
+            for data in allData {
                 add(decode: data)
             }
         }
@@ -134,10 +132,10 @@ final class ImageProgressiveProvider {
     }
 }
 
-fileprivate final class ImageProgressiveDecoder {
+private final class ImageProgressiveDecoder {
 
     private let options: KingfisherParsedOptionsInfo
-    private(set) var scannedCount: Int = 0
+    private(set) var scannedCount = 0
     private var scannedIndex = -1
 
     init(_ options: KingfisherParsedOptionsInfo) {
@@ -148,15 +146,15 @@ fileprivate final class ImageProgressiveDecoder {
         guard data.kf.contains(jpeg: .SOF2) else {
             return []
         }
-        guard (scannedIndex + 1) < data.count else {
+        guard scannedIndex + 1 < data.count else {
             return []
         }
 
         var datas: [Data] = []
         var index = scannedIndex + 1
         var count = scannedCount
 
-        while index < (data.count - 1) {
+        while index < data.count - 1 {
             scannedIndex = index
             // 0xFF, 0xDA - Start Of Scan
             let SOS = ImageFormat.JPEGMarker.SOS.bytes
@@ -184,15 +182,15 @@ fileprivate final class ImageProgressiveDecoder {
         guard data.kf.contains(jpeg: .SOF2) else {
             return nil
         }
-        guard (scannedIndex + 1) < data.count else {
+        guard scannedIndex + 1 < data.count else {
             return nil
         }
 
         var index = scannedIndex + 1
         var count = scannedCount
         var lastSOSIndex = 0
 
-        while index < (data.count - 1) {
+        while index < data.count - 1 {
             scannedIndex = index
             // 0xFF, 0xDA - Start Of Scan
             let SOS = ImageFormat.JPEGMarker.SOS.bytes
@@ -263,7 +261,7 @@ fileprivate final class ImageProgressiveDecoder {
     }
 }
 
-fileprivate final class ImageProgressiveSerialQueue {
+private final class ImageProgressiveSerialQueue {
     typealias ClosureCallback = ((@escaping () -> Void)) -> Void
 
     private let queue: DispatchQueue

Tests/KingfisherTests/DataReceivingSideEffectTests.swift

@@ -0,0 +1,51 @@
+//
+//  DataReceivingSideEffectTests.swift
+//  Kingfisher
+//
+//  Created by jp20028 on 2019/05/15.
+//
+//  Copyright (c) 2019 Wei Wang <[email protected]>
+//
+//  Permission is hereby granted, free of charge, to any person obtaining a copy
+//  of this software and associated documentation files (the "Software"), to deal
+//  in the Software without restriction, including without limitation the rights
+//  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+//  copies of the Software, and to permit persons to whom the Software is
+//  furnished to do so, subject to the following conditions:
+//
+//  The above copyright notice and this permission notice shall be included in
+//  all copies or substantial portions of the Software.
+//
+//  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+//  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+//  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+//  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+//  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+//  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+//  THE SOFTWARE.
+
+import XCTest
+
+class DataReceivingSideEffectTests: XCTestCase {
+
+    override func setUp() {
+        // Put setup code here. This method is called before the invocation of each test method in the class.
+    }
+
+    override func tearDown() {
+        // Put teardown code here. This method is called after the invocation of each test method in the class.
+    }
+
+    func testExample() {
+        // This is an example of a functional test case.
+        // Use XCTAssert and related functions to verify your tests produce the correct results.
+    }
+
+    func testPerformanceExample() {
+        // This is an example of a performance test case.
+        self.measure {
+            // Put the code you want to measure the time of here.
+        }
+    }
+
+}