FIX: Download task exist file overwrite and cleanup if fail.

Change-Id: I70a5a852492894c4b9db01f1b46050e0097e7428

Author: lancy

Docs/README_cn.md

@@ -70,6 +70,7 @@ YTKNetwork 的主要作者是：
 * [maojj][maojjGithub]
 * [veecci][veecciGithub]
 * [tangqiaoboy][tangqiaoboyGithub]
+* [skyline75489][skyline75489Github]
 
 ## 感谢
 
@@ -92,3 +93,4 @@ YTKNetwork 被许可在 MIT 协议下使用。查阅 LICENSE 文件来获得更
 [lancyGithub]:https://github.com/lancy
 [maojjGithub]:https://github.com/maojj
 [veecciGithub]:https://github.com/veecci
+[skyline75489Github]:https://github.com/skyline75489

Framework/Info.plist

@@ -15,7 +15,7 @@
 	<key>CFBundlePackageType</key>
 	<string>FMWK</string>
 	<key>CFBundleShortVersionString</key>
-	<string>2.0</string>
+	<string>2.0.3</string>
 	<key>CFBundleSignature</key>
 	<string>????</string>
 	<key>CFBundleVersion</key>

README.md

@@ -76,6 +76,7 @@ YTKNetwork is based on AFNetworking. You can find more detail about version comp
  * [maojj][maojjGithub]
  * [veecci][veecciGithub]
  * [tangqiaoboy][tangqiaoboyGithub]
+ * [skyline75489][skyline75489Github]
 
 ## Acknowledgements
 
@@ -101,3 +102,4 @@ YTKNetwork is available under the MIT license. See the LICENSE file for more inf
 [lancyGithub]:https://github.com/lancy
 [maojjGithub]:https://github.com/maojj
 [veecciGithub]:https://github.com/veecci
+[skyline75489Github]:https://github.com/skyline75489

YTKNetwork.podspec

@@ -1,7 +1,7 @@
 Pod::Spec.new do |s|
 
   s.name         = "YTKNetwork"
-  s.version      = "2.0.2"
+  s.version      = "2.0.3"
   s.summary      = "YTKNetwork is a high level request util based on AFNetworking."
   s.homepage     = "https://github.com/yuantiku/YTKNetwork"
   s.license      = "MIT"

YTKNetwork/YTKBaseRequest.h

@@ -159,7 +159,7 @@ typedef void(^YTKRequestCompletionBlock)(__kindof YTKBaseRequest *request);
 ///  `YTKResponseSerializerType`. Note this value can be nil if request failed.
 ///
 ///  @discussion If `resumableDownloadPath` and DownloadTask is using, this value will
-///              be the path to which file is successfully saved (NSURL).
+///              be the path to which file is successfully saved (NSURL), or nil if request failed.
 @property (nonatomic, strong, readonly, nullable) id responseObject;
 
 ///  If you use `YTKResponseSerializerTypeJSON`, this is a convenience (and sematic) getter
@@ -211,9 +211,11 @@ typedef void(^YTKRequestCompletionBlock)(__kindof YTKBaseRequest *request);
 
 ///  This value is used to perform resumable download request. Default is nil.
 ///
-///  @discussion NSURLSessionDownloadTask is used when this value is not nil. If request succeed, file will
-///              be saved to this path automatically. For this to work, server must support `Range` and response
-///              with proper `Last-Modified` and/or `Etag`. See `NSURLSessionDownloadTask` for more detail.
+///  @discussion NSURLSessionDownloadTask is used when this value is not nil.
+///              The exist file at the path will be removed before the request starts. If request succeed, file will
+///              be saved to this path automatically, otherwise the response will be saved to `responseData`
+///              and `responseString`. For this to work, server must support `Range` and response with
+///              proper `Last-Modified` and/or `Etag`. See `NSURLSessionDownloadTask` for more detail.
 @property (nonatomic, strong, nullable) NSString *resumableDownloadPath;
 
 ///  You can use this block to track the download progress. See also `resumableDownloadPath`.

YTKNetwork/YTKNetworkAgent.m

@@ -371,11 +371,24 @@ - (void)requestDidFailWithRequest:(YTKBaseRequest *)request error:(NSError *)err
     YTKLog(@"Request %@ failed, status code = %ld, error = %@",
            NSStringFromClass([request class]), (long)request.responseStatusCode, error.localizedDescription);
 
+    // Save incomplete download data.
     NSData *incompleteDownloadData = error.userInfo[NSURLSessionDownloadTaskResumeData];
     if (incompleteDownloadData) {
         [incompleteDownloadData writeToURL:[self incompleteDownloadTempPathForDownloadPath:request.resumableDownloadPath] atomically:YES];
     }
 
+    // Load response from file and clean up if download task failed.
+    if ([request.responseObject isKindOfClass:[NSURL class]]) {
+        NSURL *url = request.responseObject;
+        if (url.isFileURL && [[NSFileManager defaultManager] fileExistsAtPath:url.path]) {
+            request.responseData = [NSData dataWithContentsOfURL:url];
+            request.responseString = [[NSString alloc] initWithData:request.responseData encoding:[YTKNetworkUtils stringEncodingWithRequest:request]];
+
+            [[NSFileManager defaultManager] removeItemAtURL:url error:nil];
+        }
+        request.responseObject = nil;
+    }
+
     @autoreleasepool {
         [request requestFailedPreprocessor];
     }
@@ -462,6 +475,14 @@ - (NSURLSessionDownloadTask *)downloadTaskWithDownloadPath:(NSString *)downloadP
         downloadTargetPath = downloadPath;
     }
 
+    // AFN use `moveItemAtURL` to move downloaded file to target path,
+    // this method aborts the move attempt if a file already exist at the path.
+    // So we remove the exist file before we start the download task.
+    // https://github.com/AFNetworking/AFNetworking/issues/3775
+    if ([[NSFileManager defaultManager] fileExistsAtPath:downloadTargetPath]) {
+        [[NSFileManager defaultManager] removeItemAtPath:downloadTargetPath error:nil];
+    }
+
     BOOL resumeDataFileExists = [[NSFileManager defaultManager] fileExistsAtPath:[self incompleteDownloadTempPathForDownloadPath:downloadPath].path];
     NSData *data = [NSData dataWithContentsOfURL:[self incompleteDownloadTempPathForDownloadPath:downloadPath]];
     BOOL resumeDataIsValid = [YTKNetworkUtils validateResumeData:data];

YTKNetworkTests/Test Cases/YTKResumableDownloadTests.m

@@ -12,6 +12,7 @@
 #import "AFNetworking.h"
 
 NSString *const kTestDownloadURL = @"https://qd.myapp.com/myapp/qqteam/AndroidQQ/mobileqq_android.apk";
+NSString *const kTestFailDownloadURL = @"https://qd.myapp.com/myapp/qqteam/AndroidQQ/mobileqq_android.apkfail";
 
 @interface YTKResumableDownloadTests : YTKTestCase
 
@@ -97,5 +98,38 @@ - (void)testResumableDownloadWithDirectoryPath {
     [self expectSuccess:req2];
 }
 
+- (void)testResumableDownloadOverwriteAndCleanup {
+    [[YTKNetworkAgent sharedAgent] resetURLSessionManager];
+    [[YTKNetworkAgent sharedAgent] manager].responseSerializer.acceptableContentTypes = nil;
+    NSString *path = [[self saveBasePath] stringByAppendingPathComponent:@"downloaded.bin"];
+
+    // Create a exist file
+    NSString *testString = @"TEST";
+    NSData *stringData = [testString dataUsingEncoding:NSUTF8StringEncoding];
+    [stringData writeToFile:path atomically:YES];
+
+    // Download req file
+    YTKDownloadRequest *req = [[YTKDownloadRequest alloc] initWithTimeout:self.networkTimeout requestUrl:kTestDownloadURL];
+    req.resumableDownloadPath = path;
+    req.resumableDownloadProgressBlock = ^(NSProgress *progress) {
+        XCTAssertTrue(progress.completedUnitCount > 0);
+        NSLog(@"Downloading: %lld / %lld", progress.completedUnitCount, progress.totalUnitCount);
+    };
+
+    [self expectSuccess:req];
+    XCTAssertTrue([[NSFileManager defaultManager] fileExistsAtPath:path]);
+    XCTAssertTrue(([[NSFileManager defaultManager] contentsAtPath:path].length > stringData.length));
+
+    YTKDownloadRequest *req2 = [[YTKDownloadRequest alloc] initWithTimeout:self.networkTimeout requestUrl:kTestFailDownloadURL];
+    req2.resumableDownloadPath = path;
+    req2.resumableDownloadProgressBlock = ^(NSProgress *progress) {
+        XCTAssertTrue(progress.completedUnitCount > 0);
+        NSLog(@"Downloading: %lld / %lld", progress.completedUnitCount, progress.totalUnitCount);
+    };
+
+    [self expectFailure:req2];
+    XCTAssertFalse([[NSFileManager defaultManager] fileExistsAtPath:path]);
+    XCTAssertTrue(req2.responseData.length > 0 && req2.responseString.length > 0);
+}
 
 @end