TaskError should report which task failed

Author: younata

ReactiveTask/Errors.swift

@@ -12,7 +12,7 @@ import ReactiveCocoa
 /// An error originating from ReactiveTask.
 public enum TaskError: ErrorType {
 	/// A shell task exited unsuccessfully.
-	case ShellTaskFailed(exitCode: Int32, standardError: String?)
+	case ShellTaskFailed(task: Task, exitCode: Int32, standardError: String?)
 
 	/// An error was returned from a POSIX API.
 	case POSIXError(Int32)
@@ -21,8 +21,8 @@ public enum TaskError: ErrorType {
 extension TaskError: CustomStringConvertible {
 	public var description: String {
 		switch self {
-		case let .ShellTaskFailed(exitCode, standardError):
-			var description = "A shell task failed with exit code \(exitCode)"
+		case let .ShellTaskFailed(task, exitCode, standardError):
+			var description = "A shell task (\(task)) failed with exit code \(exitCode)"
 			if let standardError = standardError {
 				description += ":\n\(standardError)"
 			}

ReactiveTask/Task.swift

@@ -461,8 +461,8 @@ public func launchTask(task: Task, standardInput: SignalProducer<NSData, NoError
 					rawTask.standardError = stderrPipe.writeHandle
 
 					dispatch_group_enter(group)
-					rawTask.terminationHandler = { task in
-						let terminationStatus = task.terminationStatus
+					rawTask.terminationHandler = { nstask in
+						let terminationStatus = nstask.terminationStatus
 						if terminationStatus == EXIT_SUCCESS {
 							// Wait for stderr to finish, then pass
 							// through stdout.
@@ -477,7 +477,7 @@ public func launchTask(task: Task, standardInput: SignalProducer<NSData, NoError
 								.then(stderrAggregated)
 								.flatMap(.Concat) { data -> SignalProducer<TaskEvent<NSData>, TaskError> in
 									let errorString = (data.length > 0 ? NSString(data: data, encoding: NSUTF8StringEncoding) as? String : nil)
-									return SignalProducer(error: .ShellTaskFailed(exitCode: terminationStatus, standardError: errorString))
+									return SignalProducer(error: .ShellTaskFailed(task: task, exitCode: terminationStatus, standardError: errorString))
 								}
 								.start(observer)
 						}

ReactiveTaskTests/TaskSpec.swift

@@ -80,5 +80,17 @@ class TaskSpec: QuickSpec {
 				expect(NSString(data: data, encoding: NSUTF8StringEncoding)).to(equal("bar\nbuzz\nfoo\nfuzz\n"))
 			}
 		}
+
+		it("should error correctly") {
+			let task = Task("/usr/bin/stat", arguments: [ "not-a-real-file" ])
+			let result = launchTask(task)
+				.wait()
+
+			expect(result).notTo(beNil())
+			expect(result.error).toNot(beNil())
+			if let error = result.error {
+				expect(error.description) == "A shell task (/usr/bin/stat not-a-real-file) failed with exit code 1:\nstat: not-a-real-file: stat: No such file or directory\n"
+			}
+		}
 	}
 }