[archive] Accept a directory path input for --output option

Source/CarthageIntegration/archive.bats

@@ -18,9 +18,36 @@ teardown() {
 }
 
 @test "carthage archive after carthage build --no-skip-current produces a zipped framework of all frameworks" {
-    run carthage build --no-skip-current
+    run carthage build --platform mac --no-skip-current
     [ "$status" -eq 0 ]
     run carthage archive
     [ "$status" -eq 0 ]
     [ -e Ra.framework.zip ]
 }
+
+@test "carthage archive --output with a non-existing path ends with '/' should produce a zip file into the specified directory" {
+    run carthage build --platform mac --no-skip-current
+    [ "$status" -eq 0 ]
+    rm -rf FooBar
+    run carthage archive --output FooBar/
+    [ "$status" -eq 0 ]
+    [ -e FooBar/Ra.framework.zip ]
+}
+
+@test "carthage archive --output with an existing directory path should produce a zip file into the specified directory" {
+    run carthage build --platform mac --no-skip-current
+    [ "$status" -eq 0 ]
+    mkdir FooBar
+    run carthage archive --output FooBar
+    [ "$status" -eq 0 ]
+    [ -e FooBar/Ra.framework.zip ]
+}
+
+@test "carthage archive --output with a file path should produce a zip file at the given path" {
+    run carthage build --platform mac --no-skip-current
+    [ "$status" -eq 0 ]
+    rm -rf FooBar
+    run carthage archive --output FooBar/GreatName.framework.zip
+    [ "$status" -eq 0 ]
+    [ -e FooBar/GreatName.framework.zip ]
+}

Source/carthage/Archive.swift

@@ -108,14 +108,41 @@ public struct ArchiveCommand: CommandType {
 						return SignalProducer(error: error)
 					}
 
-					let outputPath = options.outputPath ?? "\(frameworks.first!).zip"
+					let outputPath = self.outputPathWithOptions(options, frameworks: frameworks)
 					let outputURL = NSURL(fileURLWithPath: outputPath, isDirectory: false)
 
+					if let directory = outputURL.URLByDeletingLastPathComponent {
+						_ = try? NSFileManager.defaultManager().createDirectoryAtURL(directory, withIntermediateDirectories: true, attributes: nil)
+					}
+
 					return zipIntoArchive(outputURL, paths).on(completed: {
 						carthage.println(formatting.bullets + "Created " + formatting.path(string: outputPath))
 					})
 				}
 		}
 		.waitOnCommand()
 	}
+
+	/// Returns an appropriate output file path for the resulting zip file using
+	/// the given option and frameworks.
+	private func outputPathWithOptions(options: Options, frameworks: [String]) -> String {
+		let defaultOutputPath = "\(frameworks.first!).zip"
+
+		return options.outputPath.map { path -> String in
+			if path.hasSuffix("/") {
+				// The given path should be a directory.
+				return path + defaultOutputPath
+			}
+
+			var isDirectory: ObjCBool = false
+			if NSFileManager.defaultManager().fileExistsAtPath(path, isDirectory: &isDirectory) && isDirectory {
+				// If the given path is an existing directory, output a zip file
+				// into that directory.
+				return (path as NSString).stringByAppendingPathComponent(defaultOutputPath)
+			} else {
+				// Use the given path as the final output.
+				return path
+			}
+		} ?? defaultOutputPath
+	}
 }