fix: prevent connection data loss on normal app quit

CHANGELOG.md

@@ -17,6 +17,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Fixed
 
+- Saved connections disappearing after normal app quit (Cmd+Q) while persisting after force quit (#452)
 - Detail pane showing truncated values for LONGTEXT/MEDIUMTEXT/CLOB columns, preventing correct editing
 - Redis hash/list/set/zset/stream views showing empty or misaligned rows when values contained binary, null, or integer types
 

TablePro/AppDelegate.swift

@@ -116,6 +116,7 @@ class AppDelegate: NSObject, NSApplicationDelegate {
     }
 
     func applicationWillTerminate(_ notification: Notification) {
+        UserDefaults.standard.synchronize()
         SSHTunnelManager.shared.terminateAllProcessesSync()
     }
 

TablePro/Models/Connection/DatabaseConnection.swift

@@ -500,10 +500,10 @@ struct DatabaseConnection: Identifiable, Hashable {
     }
 }
 
-// MARK: - Sample Data for Development
+// MARK: - Preview Data
 
 extension DatabaseConnection {
-    static let sampleConnections: [DatabaseConnection] = []
+    static let preview = DatabaseConnection(name: "Preview Connection")
 }
 
 // MARK: - Codable Conformance

TablePro/Views/Connection/ConnectionFormView.swift

@@ -1754,5 +1754,5 @@ private struct StartupCommandsEditor: NSViewRepresentable {
 }
 
 #Preview("Edit Connection") {
-    ConnectionFormView(connectionId: DatabaseConnection.sampleConnections[0].id)
+    ConnectionFormView(connectionId: DatabaseConnection.preview.id)
 }

TablePro/Views/Connection/WelcomeWindowView.swift

@@ -728,13 +728,7 @@ struct WelcomeWindowView: View {
     // MARK: - Actions
 
     private func loadConnections() {
-        let saved = storage.loadConnections()
-        if saved.isEmpty {
-            connections = DatabaseConnection.sampleConnections
-            storage.saveConnections(connections)
-        } else {
-            connections = saved
-        }
+        connections = storage.loadConnections()
         loadGroups()
     }
 

TablePro/Views/Main/MainContentView.swift

@@ -1067,11 +1067,11 @@ private struct FocusedCommandActionsModifier: ViewModifier {
 
 #Preview("With Connection") {
     let state = SessionStateFactory.create(
-        connection: DatabaseConnection.sampleConnections[0],
+        connection: DatabaseConnection.preview,
         payload: nil
     )
     MainContentView(
-        connection: DatabaseConnection.sampleConnections[0],
+        connection: DatabaseConnection.preview,
         payload: nil,
         windowTitle: .constant("SQL Query"),
         tables: .constant([]),

TableProTests/Core/Storage/ConnectionStoragePersistenceTests.swift

@@ -0,0 +1,56 @@
+//
+//  ConnectionStoragePersistenceTests.swift
+//  TableProTests
+//
+
+import Foundation
+import Testing
+@testable import TablePro
+
+@Suite("ConnectionStorage Persistence", .serialized)
+struct ConnectionStoragePersistenceTests {
+    private let storage = ConnectionStorage.shared
+
+    @Test("loading empty storage does not write back to UserDefaults")
+    func loadEmptyDoesNotWrite() {
+        let original = storage.loadConnections()
+        defer { storage.saveConnections(original) }
+
+        // Clear all connections
+        storage.saveConnections([])
+
+        // Force cache clear by saving then loading
+        let loaded = storage.loadConnections()
+        #expect(loaded.isEmpty)
+
+        // Add a connection directly, bypassing cache
+        let connection = DatabaseConnection(name: "Persistence Test")
+        storage.addConnection(connection)
+        defer { storage.deleteConnection(connection) }
+
+        // Loading again should return the connection, not overwrite with empty
+        let reloaded = storage.loadConnections()
+        #expect(reloaded.contains { $0.id == connection.id })
+    }
+
+    @Test("round-trip save and load preserves connections")
+    func roundTripSaveLoad() {
+        let original = storage.loadConnections()
+        defer { storage.saveConnections(original) }
+
+        let connection = DatabaseConnection(
+            name: "Round Trip Test",
+            host: "127.0.0.1",
+            port: 5432,
+            type: .postgresql
+        )
+
+        storage.saveConnections([connection])
+        let loaded = storage.loadConnections()
+
+        #expect(loaded.count == 1)
+        #expect(loaded.first?.id == connection.id)
+        #expect(loaded.first?.name == "Round Trip Test")
+        #expect(loaded.first?.host == "127.0.0.1")
+    }
+}