refactor: replace GCD dispatch patterns with Swift structured concurrency (#538)

Author: datlechin

CHANGELOG.md

@@ -17,6 +17,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Collapsible results panel (`Cmd+Opt+R`), multiple result tabs for multi-statement queries, result pinning
 - Inline error banner for query errors
 
+### Changed
+
+- Replace GCD dispatch patterns with Swift structured concurrency
+
 ### Fixed
 
 - SQL Server: Unicode characters (Thai, CJK, etc.) in nvarchar/nchar/ntext columns displaying as question marks

TablePro/AppDelegate+WindowConfig.swift

@@ -326,34 +326,31 @@ extension AppDelegate {
 
         isAutoReconnecting = true
 
-        DispatchQueue.main.async { [weak self] in
+        Task { @MainActor [weak self] in
             guard let self else { return }
             WindowOpener.shared.pendingConnectionId = connection.id
             NotificationCenter.default.post(name: .openMainWindow, object: connection.id)
 
-            Task { @MainActor in
-                defer { self.isAutoReconnecting = false }
-                do {
-                    try await DatabaseManager.shared.connectToSession(connection)
-
-                    for window in NSApp.windows where self.isWelcomeWindow(window) {
-                        window.close()
-                    }
-                } catch is CancellationError {
-                    // User cancelled password prompt at startup — return to welcome
-                    for window in NSApp.windows where self.isMainWindow(window) {
-                        window.close()
-                    }
-                    self.openWelcomeWindow()
-                } catch {
-                    windowLogger.error("Auto-reconnect failed for '\(connection.name)': \(error.localizedDescription)")
+            defer { self.isAutoReconnecting = false }
+            do {
+                try await DatabaseManager.shared.connectToSession(connection)
 
-                    for window in NSApp.windows where self.isMainWindow(window) {
-                        window.close()
-                    }
+                for window in NSApp.windows where self.isWelcomeWindow(window) {
+                    window.close()
+                }
+            } catch is CancellationError {
+                for window in NSApp.windows where self.isMainWindow(window) {
+                    window.close()
+                }
+                self.openWelcomeWindow()
+            } catch {
+                windowLogger.error("Auto-reconnect failed for '\(connection.name)': \(error.localizedDescription)")
 
-                    self.openWelcomeWindow()
+                for window in NSApp.windows where self.isMainWindow(window) {
+                    window.close()
                 }
+
+                self.openWelcomeWindow()
             }
         }
     }

TablePro/Core/Services/Formatting/SQLFormatterService.swift

@@ -133,12 +133,7 @@ struct SQLFormatterService: SQLFormatterProtocol {
     }
 
     private static func resolveDialectProvider(for dialect: DatabaseType) -> SQLDialectProvider {
-        if Thread.isMainThread {
-            return MainActor.assumeIsolated { SQLDialectFactory.createDialect(for: dialect) }
-        }
-        return DispatchQueue.main.sync {
-            MainActor.assumeIsolated { SQLDialectFactory.createDialect(for: dialect) }
-        }
+        SQLDialectFactory.createDialect(for: dialect)
     }
 
     // MARK: - Public API

TablePro/Core/Services/Query/SQLDialectProvider.swift

@@ -36,9 +36,10 @@ private struct EmptyDialect: SQLDialectProvider {
 // MARK: - Dialect Factory
 
 struct SQLDialectFactory {
-    @MainActor
     static func createDialect(for databaseType: DatabaseType) -> SQLDialectProvider {
-        if let descriptor = PluginManager.shared.sqlDialect(for: databaseType) {
+        if let descriptor = PluginMetadataRegistry.shared.snapshot(
+            forTypeId: databaseType.pluginTypeId
+        )?.editor.sqlDialect {
             return PluginDialectAdapter(descriptor: descriptor)
         }
         return EmptyDialect()

TablePro/Views/AIChat/AIChatCodeBlockView.swift

@@ -43,7 +43,8 @@ struct AIChatCodeBlockView: View {
             Button {
                 ClipboardService.shared.writeText(code)
                 isCopied = true
-                DispatchQueue.main.asyncAfter(deadline: .now() + 1.5) {
+                Task { @MainActor in
+                    try? await Task.sleep(for: .seconds(1.5))
                     isCopied = false
                 }
             } label: {

TablePro/Views/Components/SQLReviewPopover.swift

@@ -200,7 +200,8 @@ struct SQLReviewPopover: View {
         ClipboardService.shared.writeText(joined)
         copied = true
 
-        DispatchQueue.main.asyncAfter(deadline: .now() + 1.5) {
+        Task { @MainActor in
+            try? await Task.sleep(for: .seconds(1.5))
             copied = false
         }
     }

TablePro/Views/Components/SyncStatusIndicator.swift

@@ -120,7 +120,8 @@ struct SyncStatusIndicator: View {
             showActivationSheet = true
         default:
             UserDefaults.standard.set(SettingsTab.sync.rawValue, forKey: "selectedSettingsTab")
-            DispatchQueue.main.asyncAfter(deadline: .now() + 0.1) {
+            Task { @MainActor in
+                try? await Task.sleep(for: .milliseconds(100))
                 NSApp.sendAction(Selector(("showSettingsWindow:")), to: nil, from: nil)
             }
         }

TablePro/Views/Connection/ConnectionExportOptionsSheet.swift

@@ -95,7 +95,8 @@ struct ConnectionExportOptionsSheet: View {
         confirmPassphrase = ""
         dismiss()
 
-        DispatchQueue.main.asyncAfter(deadline: .now() + 0.2) {
+        Task { @MainActor in
+            try? await Task.sleep(for: .milliseconds(200))
             let panel = NSSavePanel()
             panel.allowedContentTypes = [.tableproConnectionShare]
             let defaultName = capturedConnections.count == 1

TablePro/Views/Connection/WelcomeWindowView.swift

@@ -78,7 +78,8 @@ struct WelcomeWindowView: View {
                 LicenseActivationSheet()
             case .importFile(let url):
                 ConnectionImportSheet(fileURL: url) { count in
-                    DispatchQueue.main.asyncAfter(deadline: .now() + 0.3) {
+                    Task { @MainActor in
+                        try? await Task.sleep(for: .milliseconds(300))
                         vm.showImportResultAlert(count: count)
                     }
                 }

TablePro/Views/Editor/EditorEventRouter.swift

@@ -39,7 +39,7 @@ internal final class EditorEventRouter {
         if textView.window != nil {
             installWindowObserver(for: key)
         } else {
-            DispatchQueue.main.async { [weak self] in
+            Task { [weak self] in
                 guard let self, self.editors[key]?.windowObserver == nil else { return }
                 self.installWindowObserver(for: key)
             }