Don't use semaphores for blocking

davedelong · davedelong · commit a86ee36c1796 · 2025-07-16T08:29:04.000-06:00
Methods with completion handlers, like the ones used on NSWorkspace, get imported as async methods to Swift Concurrency. This requires updating command definitions to be async.
diff --git a/Sources/utiluti/AppCommands.swift b/Sources/utiluti/AppCommands.swift
@@ -10,7 +10,7 @@ import ArgumentParser
 import UniformTypeIdentifiers
 import AppKit // for NSWorkspace
 
-struct AppCommands: ParsableCommand {
+struct AppCommands: AsyncParsableCommand {
   static let configuration = CommandConfiguration(
     commandName: "app",
     abstract: "list uniform types identifiers and url schemes associated with an app",
@@ -20,7 +20,7 @@ struct AppCommands: ParsableCommand {
     ]
   )
   
-  struct Types: ParsableCommand {
+  struct Types: AsyncParsableCommand {
     static let configuration
     = CommandConfiguration(abstract: "List the uniform type identifiers this app can open")
     
@@ -31,7 +31,7 @@ struct AppCommands: ParsableCommand {
           help: "show more information")
     var verbose: Bool = false
     
-    func run() {
+    func run() async {
       guard
         let appURL = NSWorkspace.shared.urlForApplication(withBundleIdentifier: appID),
         let appBundle = Bundle(url: appURL),
@@ -82,7 +82,7 @@ struct AppCommands: ParsableCommand {
     }
   }
   
-  struct Schemes: ParsableCommand {
+  struct Schemes: AsyncParsableCommand {
     static let configuration
     = CommandConfiguration(abstract: "List the urls schemes this app can open")
     
@@ -93,7 +93,7 @@ struct AppCommands: ParsableCommand {
           help: "show more information")
     var verbose: Bool = false
     
-    func run() {
+    func run() async {
       guard
         let appURL = NSWorkspace.shared.urlForApplication(withBundleIdentifier: appID),
         let appBundle = Bundle(url: appURL),
diff --git a/Sources/utiluti/FileCommands.swift b/Sources/utiluti/FileCommands.swift
@@ -12,7 +12,7 @@ import ArgumentParser
 import UniformTypeIdentifiers
 import AppKit // for NSWorkspace
 
-struct FileCommands: ParsableCommand {
+struct FileCommands: AsyncParsableCommand {
   
   static var subCommands: [ParsableCommand.Type] {
     if #available(macOS 12.0, *) {
@@ -28,21 +28,21 @@ struct FileCommands: ParsableCommand {
     subcommands: subCommands
   )
   
-  struct GetUTI: ParsableCommand {
+  struct GetUTI: AsyncParsableCommand {
     static let configuration
     = CommandConfiguration(abstract: "get the uniform type identifier of a file")
     
     @Argument(help:ArgumentHelp("file path", valueName: "path"))
     var path: String
     
-    func run() {
+    func run() async {
       let url = URL(fileURLWithPath: path)
       let typeIdentifier = try? url.resourceValues(forKeys: [.typeIdentifierKey]).typeIdentifier
       print(typeIdentifier ?? "<unknown>")
     }
   }
   
-  struct App: ParsableCommand {
+  struct App: AsyncParsableCommand {
     static let configuration
     = CommandConfiguration(abstract: "get the app that will open this file")
     
@@ -54,7 +54,7 @@ struct FileCommands: ParsableCommand {
       valueName: "bundleID"))
     var bundleID = false
     
-    func run() {
+    func run() async {
       let url = URL(fileURLWithPath: path)
       if let app = NSWorkspace.shared.urlForApplication(toOpen: url) {
         if bundleID {
@@ -73,7 +73,7 @@ struct FileCommands: ParsableCommand {
   }
   
   @available(macOS 12, *)
-  struct ListApps: ParsableCommand {
+  struct ListApps: AsyncParsableCommand {
     static let configuration
     = CommandConfiguration(abstract: "get all app that can open this file")
     
@@ -85,7 +85,7 @@ struct FileCommands: ParsableCommand {
       valueName: "bundleID"))
     var bundleID = false
     
-    func run() {
+    func run() async {
       let url = URL(fileURLWithPath: path)
       let apps = NSWorkspace.shared.urlsForApplications(toOpen: url)
       for app in apps {
diff --git a/Sources/utiluti/GetUTI.swift b/Sources/utiluti/GetUTI.swift
@@ -9,7 +9,7 @@ import Foundation
 import ArgumentParser
 import UniformTypeIdentifiers
 
-struct GetUTI: ParsableCommand {
+struct GetUTI: AsyncParsableCommand {
   static let configuration
   = CommandConfiguration(abstract: "Get the type identifier (UTI) for a file extension")
   
@@ -19,7 +19,7 @@ struct GetUTI: ParsableCommand {
   @Flag(help: "show dynamic identifiers")
   var showDynamic = false
   
-  func run() {
+  func run() async {
     guard let utype = UTType(filenameExtension: fileExtension) else {
       Self.exit(withError: ExitCode(3))
     }
diff --git a/Sources/utiluti/LSKit.swift b/Sources/utiluti/LSKit.swift
@@ -65,27 +65,21 @@ struct LSKit {
    - scheme: url scheme (excluding the `:` or `/`, e.g. `http`)
    - Returns: OSStatus (discardable)
    */
-  @discardableResult static func setDefaultApp(identifier: String, forScheme scheme: String) -> OSStatus {
+  @discardableResult static func setDefaultApp(identifier: String, forScheme scheme: String) async -> OSStatus {
     if #available(macOS 12, *) {
       // print("running on macOS 12, using NSWorkspace")
-      let ws = NSWorkspace.shared
-      
-      // since the new NSWorkspace function is asynchronous we have to use semaphores here
-      let semaphore = DispatchSemaphore(value: 0)
-      var errCode: OSStatus = 0
-      
-      guard let appURL = ws.urlForApplication(withBundleIdentifier: identifier) else { return 1 }
-      ws.setDefaultApplication(at: appURL, toOpenURLsWithScheme: scheme) { err in
-        // err is an NSError wrapped in a CocoaError
-        if let err = err as? CocoaError {
-          if let underlyingError = err.errorUserInfo["NSUnderlyingError"] as? NSError {
-            errCode = OSStatus(clamping: underlyingError.code)
-          }
+      do {
+        let ws = NSWorkspace.shared
+        guard let appURL = ws.urlForApplication(withBundleIdentifier: identifier) else { return 1 }
+        try await ws.setDefaultApplication(at: appURL, toOpenURLsWithScheme: scheme)
+        return 0
+      } catch {
+        if let err = error as? CocoaError, let underlyingError = err.errorUserInfo["NSUnderlyingError"] as? NSError {
+          return OSStatus(clamping: underlyingError.code)
+        } else {
+          return 1
         }
-        semaphore.signal()
       }
-      semaphore.wait()
-      return errCode
     } else {
       return LSSetDefaultHandlerForURLScheme(scheme as CFString, identifier as CFString)
     }
@@ -147,31 +141,26 @@ struct LSKit {
    - forTypeIdentifier: uniform type identifier ( e.g. `public.html`)
    - Returns: OSStatus (discardable)
    */
-  @discardableResult static func setDefaultApp(identifier: String, forTypeIdentifier utidentifier: String) -> OSStatus {
+  @discardableResult static func setDefaultApp(identifier: String, forTypeIdentifier utidentifier: String) async -> OSStatus {
     if #available(macOS 12, *) {
       // print("running on macOS 12, using NSWorkspace")
       guard let utype = UTType(utidentifier) else {
         return 1
       }
-
-      let ws = NSWorkspace.shared
       
-      // since the new NSWorkspace function is asynchronous we have to use semaphores here
-      let semaphore = DispatchSemaphore(value: 0)
-      var errCode: OSStatus = 0
-      
-      guard let appURL = ws.urlForApplication(withBundleIdentifier: identifier) else { return 1 }
-      ws.setDefaultApplication(at: appURL, toOpen: utype) { err in
+      do {
+        let ws = NSWorkspace.shared
+        guard let appURL = ws.urlForApplication(withBundleIdentifier: identifier) else { return 1 }
+        try await ws.setDefaultApplication(at: appURL, toOpen: utype)
+        return 0
+      } catch {
         // err is an NSError wrapped in a CocoaError
-        if let err = err as? CocoaError {
-          if let underlyingError = err.errorUserInfo["NSUnderlyingError"] as? NSError {
-            errCode = OSStatus(clamping: underlyingError.code)
-          }
+        if let err = error as? CocoaError, let underlyingError = err.errorUserInfo["NSUnderlyingError"] as? NSError {
+          return OSStatus(clamping: underlyingError.code)
+        } else {
+          return 1
         }
-        semaphore.signal()
       }
-      semaphore.wait()
-      return errCode
     } else {
       return LSSetDefaultRoleHandlerForContentType(utidentifier as CFString, .all, identifier as CFString)
     }
diff --git a/Sources/utiluti/ManageCommand.swift b/Sources/utiluti/ManageCommand.swift
@@ -8,7 +8,7 @@
 import Foundation
 import ArgumentParser
 
-struct ManageCommand: ParsableCommand {
+struct ManageCommand: AsyncParsableCommand {
   static let configuration = CommandConfiguration(
     commandName: "manage",
     abstract: "read and apply settings from a managed preferences or a file"
@@ -47,15 +47,15 @@ struct ManageCommand: ParsableCommand {
     return prefs.dictionaryRepresentation(forKeys: Array(keys))
   }
 
-  func manageTypes(types: [String:Any]) throws {
+  func manageTypes(types: [String:Any]) async throws {
     for (uti, value) in types {
       guard let bundleID = value as? String
       else {
         if verbose { print("skipping non-string value '\(value)' for \(uti)")}
         continue
       }
 
-      let result = LSKit.setDefaultApp(identifier: bundleID, forTypeIdentifier: uti)
+      let result = await LSKit.setDefaultApp(identifier: bundleID, forTypeIdentifier: uti)
       if result == 0 {
         print("set \(bundleID) for \(uti)")
       } else {
@@ -64,15 +64,15 @@ struct ManageCommand: ParsableCommand {
     }
   }
 
-  func manageURLs(urls: [String:Any]) throws {
+  func manageURLs(urls: [String:Any]) async throws {
     for (urlScheme, value) in urls {
       guard let bundleID = value as? String
       else {
         if verbose { print("skipping non-string value '\(value)' for \(urlScheme)")}
         continue
       }
 
-      let result = LSKit.setDefaultApp(identifier: bundleID, forScheme: urlScheme)
+      let result = await LSKit.setDefaultApp(identifier: bundleID, forScheme: urlScheme)
 
       if result == 0 {
         print("set \(bundleID) for \(urlScheme)")
@@ -82,24 +82,24 @@ struct ManageCommand: ParsableCommand {
     }
   }
 
-  func run() throws {
+  func run() async throws {
     if typeFile == nil && urlFile == nil {
       // neither file path is set, read from defaults
       let types = try dictionary(fromDefaults: "com.scriptingosx.utiluti.type")
-      try manageTypes(types: types)
+      try await manageTypes(types: types)
 
       let urls = try dictionary(fromDefaults: "com.scriptingosx.utiluti.url")
-      try manageURLs(urls: urls)
+      try await manageURLs(urls: urls)
     } else {
       // one or both of the file paths are set
       if let typeFile {
         let types = try dictionary(forFile: typeFile)
-        try manageTypes(types: types)
+        try await manageTypes(types: types)
       }
 
       if let urlFile {
         let urls = try dictionary(forFile: urlFile)
-        try manageURLs(urls: urls)
+        try await manageURLs(urls: urls)
       }
     }
   }
diff --git a/Sources/utiluti/TypeCommands.swift b/Sources/utiluti/TypeCommands.swift
@@ -9,7 +9,7 @@ import Foundation
 import ArgumentParser
 import UniformTypeIdentifiers
 
-struct TypeCommands: ParsableCommand {
+struct TypeCommands: AsyncParsableCommand {
 
   static let configuration = CommandConfiguration(
     commandName: "type",
@@ -38,14 +38,14 @@ struct TypeCommands: ParsableCommand {
     var bundleID = false
   }
   
-  struct Get: ParsableCommand {
+  struct Get: AsyncParsableCommand {
     static let configuration
     = CommandConfiguration(abstract: "Get the path to the default application.")
     
     @OptionGroup var utidentifier: UTIdentifier
     @OptionGroup var bundleID: IdentifierFlag
     
-    func run() {
+    func run() async {
       guard let appURL = LSKit.defaultAppURL(forTypeIdentifier: utidentifier.value) else {
         print("<no default app found>")
         return
@@ -61,14 +61,14 @@ struct TypeCommands: ParsableCommand {
     }
   }
   
-  struct List: ParsableCommand {
+  struct List: AsyncParsableCommand {
     static let configuration
     = CommandConfiguration(abstract: "List all applications that can handle this type identifier.")
     
     @OptionGroup var utidentifier: UTIdentifier
     @OptionGroup var bundleID: IdentifierFlag
 
-    func run() {
+    func run() async {
       let appURLs = LSKit.appURLs(forTypeIdentifier: utidentifier.value)
       
       for appURL in appURLs {
@@ -85,15 +85,15 @@ struct TypeCommands: ParsableCommand {
     }
   }
   
-  struct Set: ParsableCommand {
+  struct Set: AsyncParsableCommand {
     static let configuration
     = CommandConfiguration(abstract: "Set the default app for this type identifier.")
     
     @OptionGroup var utidentifier: UTIdentifier
     @Argument var identifier: String
     
-    func run() {
-      let result = LSKit.setDefaultApp(identifier: identifier, forTypeIdentifier: utidentifier.value)
+    func run() async {
+      let result = await LSKit.setDefaultApp(identifier: identifier, forTypeIdentifier: utidentifier.value)
       
       if result == 0 {
         print("set \(identifier) for \(utidentifier.value)")
@@ -104,13 +104,13 @@ struct TypeCommands: ParsableCommand {
     }
   }
   
-  struct FileExtensions: ParsableCommand {
+  struct FileExtensions: AsyncParsableCommand {
     static let configuration
     = CommandConfiguration(abstract: "prints the file extensions for the given type identifier")
     
     @OptionGroup var utidentifier: UTIdentifier
     
-    func run() {
+    func run() async {
       guard let utype = UTType(utidentifier.value) else {
         print("<none>")
         TypeCommands.exit(withError: ExitCode(3))
@@ -121,13 +121,13 @@ struct TypeCommands: ParsableCommand {
     }
   }
 
-  struct Info: ParsableCommand {
+  struct Info: AsyncParsableCommand {
     static let configuration
     = CommandConfiguration(abstract: "prints information for the given type identifier")
 
     @OptionGroup var utidentifier: UTIdentifier
     
-    func run() {
+    func run() async {
       guard let utype = UTType(utidentifier.value) else {
         print("<none>")
         TypeCommands.exit(withError: ExitCode(3))
diff --git a/Sources/utiluti/URLCommands.swift b/Sources/utiluti/URLCommands.swift
