Don't print an additional error message when exiting

Author: natecook1000

Package.resolved

@@ -26,7 +26,7 @@ let package = Package(
       .revision("swift-DEVELOPMENT-SNAPSHOT-2020-01-29-a")
     ),
     .package(url: "https://github.com/apple/swift-tools-support-core.git", from: "0.0.1"),
-    .package(url: "https://github.com/apple/swift-argument-parser.git", .upToNextMinor(from: "0.0.1")),
+    .package(url: "https://github.com/apple/swift-argument-parser.git", .upToNextMinor(from: "0.0.2")),
   ],
   targets: [
     .target(

Package.swift

@@ -16,6 +16,7 @@ import SwiftFormatConfiguration
 import SwiftFormatCore
 import SwiftSyntax
 import TSCBasic
+import ArgumentParser
 
 extension SwiftFormatCommand {
   func run() throws {
@@ -58,10 +59,10 @@ extension SwiftFormatCommand {
       try dumpDefaultConfiguration()
     }
 
-    // If any of the operations have generated diagnostics, throw an error
-    // to exit with the error status code.
+    // If any of the operations have generated diagnostics, exit with the
+    // error status code.
     if !diagnosticEngine.diagnostics.isEmpty {
-      throw FormatError.exitWithDiagnosticErrors
+      throw ExitCode.failure
     }
   }
 }