Implement -[NSData writeToURL:options:error:]

Foundation.xcodeproj/project.pbxproj

@@ -7,6 +7,7 @@
 	objects = {
 
 /* Begin PBXBuildFile section */
+		366C227D1C1649590069EBFD /* TestNSData.swift in Sources */ = {isa = PBXBuildFile; fileRef = 366C227C1C1649590069EBFD /* TestNSData.swift */; };
 		4DC1D0801C12EEEF00B5948A /* TestNSPipe.swift in Sources */ = {isa = PBXBuildFile; fileRef = 4DC1D07F1C12EEEF00B5948A /* TestNSPipe.swift */; };
 		525AECED1BF2C9C500D15BB0 /* TestNSFileManager.swift in Sources */ = {isa = PBXBuildFile; fileRef = 525AECEB1BF2C96400D15BB0 /* TestNSFileManager.swift */; };
 		528776141BF2629700CB0090 /* FoundationErrors.swift in Sources */ = {isa = PBXBuildFile; fileRef = 522C253A1BF16E1600804FC6 /* FoundationErrors.swift */; };
@@ -314,6 +315,7 @@
 /* End PBXCopyFilesBuildPhase section */
 
 /* Begin PBXFileReference section */
+		366C227C1C1649590069EBFD /* TestNSData.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = TestNSData.swift; sourceTree = "<group>"; };
 		4DC1D07F1C12EEEF00B5948A /* TestNSPipe.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = TestNSPipe.swift; sourceTree = "<group>"; };
 		522C253A1BF16E1600804FC6 /* FoundationErrors.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = FoundationErrors.swift; sourceTree = "<group>"; };
 		525AECEB1BF2C96400D15BB0 /* TestNSFileManager.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = TestNSFileManager.swift; sourceTree = "<group>"; };
@@ -1015,6 +1017,7 @@
 				5BC1D8BC1BF3ADFE009D3973 /* TestNSCharacterSet.swift */,
 				525AECEB1BF2C96400D15BB0 /* TestNSFileManager.swift */,
 				5B40F9F11C125187000E72E3 /* TestNSXMLParser.swift */,
+				366C227C1C1649590069EBFD /* TestNSData.swift */,
 			);
 			name = Tests;
 			sourceTree = "<group>";
@@ -1704,6 +1707,7 @@
 				4DC1D0801C12EEEF00B5948A /* TestNSPipe.swift in Sources */,
 				EA66F64E1BF1619600136161 /* TestNSIndexSet.swift in Sources */,
 				EA66F6541BF1619600136161 /* TestNSSet.swift in Sources */,
+				366C227D1C1649590069EBFD /* TestNSData.swift in Sources */,
 				EA66F64A1BF1619600136161 /* TestNSArray.swift in Sources */,
 				5BC1D8BE1BF3B09E009D3973 /* TestNSCharacterSet.swift in Sources */,
 				EA66F6561BF1619600136161 /* TestNSString.swift in Sources */,

Foundation/NSData.swift

@@ -431,9 +431,22 @@ extension NSData {
         }
         return false
     }
-
+
+    ///    Write the contents of the receiver to a location specified by the given file URL.
+    ///
+    ///    - parameter url:              The location to which the receiver’s contents will be written.
+    ///    - parameter writeOptionsMask: An option set specifying file writing options.
+    ///
+    ///    - throws: This method returns Void and is marked with the `throws` keyword to indicate that it throws an error in the event of failure.
+    ///
+    ///      This method is invoked in a `try` expression and the caller is responsible for handling any errors in the `catch` clauses of a `do` statement, as described in [Error Handling](https://developer.apple.com/library/prerelease/ios/documentation/Swift/Conceptual/Swift_Programming_Language/ErrorHandling.html#//apple_ref/doc/uid/TP40014097-CH42) in [The Swift Programming Language](https://developer.apple.com/library/prerelease/ios/documentation/Swift/Conceptual/Swift_Programming_Language/index.html#//apple_ref/doc/uid/TP40014097) and [Error Handling](https://developer.apple.com/library/prerelease/ios/documentation/Swift/Conceptual/BuildingCocoaApps/AdoptingCocoaDesignPatterns.html#//apple_ref/doc/uid/TP40014216-CH7-ID10) in [Using Swift with Cocoa and Objective-C](https://developer.apple.com/library/prerelease/ios/documentation/Swift/Conceptual/BuildingCocoaApps/index.html#//apple_ref/doc/uid/TP40014216).
     public func writeToURL(url: NSURL, options writeOptionsMask: NSDataWritingOptions) throws {
-        NSUnimplemented()
+        guard let path = url.path where url.fileURL == true else {
+            let userInfo = [NSLocalizedDescriptionKey : "The folder at “\(url)” does not exist or is not a file URL." as NSString, // NSLocalizedString() not yet available
+                            NSURLErrorKey             : url.absoluteString as NSString? ?? ""]
+            throw NSError(domain: NSCocoaErrorDomain, code: 4, userInfo: userInfo)
+        }
+        try writeToFile(path, options: writeOptionsMask)
     }
 
     internal func enumerateByteRangesUsingBlockRethrows(block: (UnsafePointer<Void>, NSRange, UnsafeMutablePointer<Bool>) throws -> Void) throws {

TestFoundation/TestNSData.swift

@@ -0,0 +1,42 @@
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2014 - 2015 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See http://swift.org/LICENSE.txt for license information
+// See http://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+
+
+
+#if DEPLOYMENT_RUNTIME_OBJC || os(Linux)
+    import Foundation
+    import XCTest
+#else
+    import SwiftFoundation
+    import SwiftXCTest
+#endif
+
+
+
+class TestNSData : XCTestCase {
+
+    var allTests : [(String, () -> ())] {
+        return [
+            ("test_writeToURLOptions", test_writeToURLOptions)
+        ]
+    }
+
+    func test_writeToURLOptions() {
+        let saveData = NSData(contentsOfURL: NSBundle.mainBundle().URLForResource("Test", withExtension: "plist")!)
+        let savePath = "/var/tmp/Test.plist"
+        do {
+            try saveData!.writeToFile(savePath, options: NSDataWritingOptions.DataWritingAtomic)
+            let fileManager = NSFileManager.defaultManager()
+            XCTAssertTrue(fileManager.fileExistsAtPath(savePath))
+            try! fileManager.removeItemAtPath(savePath)
+        } catch let error {
+            XCTFail((error as! NSError).localizedDescription)
+        }
+    }
+}

TestFoundation/main.swift

@@ -34,4 +34,5 @@ XCTMain([
     TestNSFileManger(),
     TestNSRange(),
     TestNSXMLParser(),
+    TestNSData()
 ])