Minor cleanup for TaskError and Equatable

Author: ikesyo

ReactiveTask/Errors.swift

@@ -10,7 +10,7 @@ import Foundation
 import ReactiveCocoa
 
 /// An error originating from ReactiveTask.
-public enum TaskError: ErrorType {
+public enum TaskError: ErrorType, Equatable {
 	/// A shell task exited unsuccessfully.
 	case ShellTaskFailed(Task, exitCode: Int32, standardError: String?)
 
@@ -35,14 +35,14 @@ extension TaskError: CustomStringConvertible {
 	}
 }
 
-extension TaskError: Equatable {}
-
-public func ==(lhs: TaskError, rhs: TaskError) -> Bool {
+public func == (lhs: TaskError, rhs: TaskError) -> Bool {
 	switch (lhs, rhs) {
-	case (.ShellTaskFailed(let lhsTask, let lhsCode, let lhsErr), .ShellTaskFailed(let rhsTask, let rhsCode, let rhsErr)):
+	case let (.ShellTaskFailed(lhsTask, lhsCode, lhsErr), .ShellTaskFailed(rhsTask, rhsCode, rhsErr)):
 		return lhsTask == rhsTask && lhsCode == rhsCode && lhsErr == rhsErr
-	case (.POSIXError(let lhsCode), .POSIXError(let rhsCode)):
+
+	case let (.POSIXError(lhsCode), .POSIXError(rhsCode)):
 		return lhsCode == rhsCode
+
 	default:
 		return false
 	}

ReactiveTaskTests/TaskSpec.swift

@@ -87,7 +87,7 @@ class TaskSpec: QuickSpec {
 				.wait()
 
 			expect(result).notTo(beNil())
-			expect(result.error).toNot(beNil())
+			expect(result.error).notTo(beNil())
 			expect(result.error) == TaskError.ShellTaskFailed(task, exitCode: 1, standardError: "stat: not-a-real-file: stat: No such file or directory\n")
 			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"