refactor: sidebar architecture - single source of truth, explicit loading states (#690)

* refactor: sidebar architecture - single source of truth, explicit loading states

* fix: address review issues - skip double fetch, restore stale cleanup, fix error path

* docs: simplify unreleased changelog entries

Author: datlechin

CHANGELOG.md

@@ -9,16 +9,18 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Added
 
-- Full-text search across all columns in iOS data browser
-- iPad keyboard shortcuts (Cmd+N new connection, Cmd+Return execute query, Cmd+1/2 switch tabs) and trackpad hover effects on list rows
-- Server Dashboard with active sessions, server metrics, and slow query monitoring (PostgreSQL, MySQL, MSSQL, ClickHouse, DuckDB, SQLite)
-- Handoff support for cross-device continuity between iOS and macOS
-- State restoration across app lifecycle on iOS (selected connection, active tab, query text, database/schema selection)
+- Server Dashboard: active sessions, metrics, slow queries (PostgreSQL, MySQL, MSSQL, ClickHouse, DuckDB, SQLite)
+- Handoff support between iOS and macOS
+- iOS: full-text search in data browser, state restoration, iPad keyboard shortcuts
+
+### Changed
+
+- Sidebar table loading refactored: single source of truth, explicit loading states, no race conditions on database switch
 
 ### Fixed
 
-- Create Database dialog showing MySQL charset/collation options for all database types; now shows database-specific options (encoding/LC_COLLATE for PostgreSQL, hidden for Redis/etcd)
-- SSH Tunnel not working with `~/.ssh/config` profiles (#672): added `Include` directive support, SSH token expansion (`%d`, `%h`, `%u`, `%r`), multi-word `Host` filtering, and detailed handshake error messages
+- Create Database dialog now shows correct options per database type (encoding/LC_COLLATE for PostgreSQL, hidden for Redis/etcd)
+- SSH tunnel with `~/.ssh/config` profiles (#672): `Include` directives, token expansion, multi-word `Host` filtering
 
 ## [0.30.1] - 2026-04-10
 

TablePro/ContentView.swift

@@ -184,7 +184,6 @@ struct ContentView: View {
                         tableOperationOptions: sessionTableOperationOptionsBinding,
                         databaseType: currentSession.connection.type,
                         connectionId: currentSession.connection.id,
-                        schemaProvider: SchemaProviderRegistry.shared.provider(for: currentSession.connection.id),
                         coordinator: sessionState.coordinator
                     )
                 }

TablePro/Core/Autocomplete/SQLSchemaProvider.swift

@@ -107,27 +107,17 @@ actor SQLSchemaProvider {
         isLoading
     }
 
-    /// Invalidate cache and reload
-    func invalidateCache() {
-        tables.removeAll()
-        columnCache.removeAll()
-        columnAccessOrder.removeAll()
-        cachedDriver = nil
-    }
-
-    func invalidateTables() {
-        tables.removeAll()
-    }
-
     func updateTables(_ newTables: [TableInfo]) {
         tables = newTables
     }
 
-    func fetchFreshTables() async throws -> [TableInfo]? {
-        guard let driver = cachedDriver else { return nil }
-        let fresh = try await driver.fetchTables()
-        tables = fresh
-        return fresh
+    func resetForDatabase(_ database: String?, tables newTables: [TableInfo], driver: DatabaseDriver) {
+        self.tables = newTables
+        self.columnCache.removeAll()
+        self.columnAccessOrder.removeAll()
+        self.cachedDriver = driver
+        self.isLoading = false
+        self.lastLoadError = nil
     }
 
     /// Find table name from alias

TablePro/ViewModels/SidebarViewModel.swift

@@ -3,63 +3,18 @@
 //  TablePro
 //
 //  ViewModel for SidebarView.
-//  Handles table loading, search filtering, and batch operations.
+//  Handles search filtering and batch operations.
 //
 
 import Observation
-import os
 import SwiftUI
 
-// MARK: - TableFetcher Protocol
-
-/// Abstraction over table fetching for testability
-protocol TableFetcher: Sendable {
-    func fetchTables(force: Bool) async throws -> [TableInfo]
-}
-
-private let sidebarLogger = Logger(subsystem: "com.TablePro", category: "SidebarViewModel")
-
-/// Production implementation that uses DatabaseManager, with optional schema provider cache
-struct LiveTableFetcher: TableFetcher {
-    let connectionId: UUID
-    let schemaProvider: SQLSchemaProvider?
-
-    init(connectionId: UUID, schemaProvider: SQLSchemaProvider? = nil) {
-        self.connectionId = connectionId
-        self.schemaProvider = schemaProvider
-    }
-
-    func fetchTables(force: Bool) async throws -> [TableInfo] {
-        if let provider = schemaProvider {
-            if force {
-                if let fresh = try await provider.fetchFreshTables() { return fresh }
-            } else {
-                let cached = await provider.getTables()
-                if !cached.isEmpty { return cached }
-            }
-        }
-        guard let driver = await DatabaseManager.shared.driver(for: connectionId) else {
-            sidebarLogger.warning("Driver is nil for connection \(connectionId)")
-            return []
-        }
-        let fetched = try await driver.fetchTables()
-            .sorted { $0.name.localizedCaseInsensitiveCompare($1.name) == .orderedAscending }
-        sidebarLogger.debug("Fetched \(fetched.count) tables")
-        if let provider = schemaProvider {
-            await provider.updateTables(fetched)
-        }
-        return fetched
-    }
-}
-
 // MARK: - SidebarViewModel
 
 @MainActor @Observable
 final class SidebarViewModel {
     // MARK: - Published State
 
-    var isLoading = false
-    var errorMessage: String?
     var debouncedSearchText = ""
     var isTablesExpanded: Bool = {
         let key = "sidebar.isTablesExpanded"
@@ -84,11 +39,6 @@ final class SidebarViewModel {
     var pendingOperationType: TableOperationType?
     var pendingOperationTables: [String] = []
 
-    // MARK: - Internal State
-
-    /// Prevents selection callback during programmatic updates (e.g., refresh)
-    var isRestoringSelection = false
-
     // MARK: - Binding Storage
 
     private var tablesBinding: Binding<[TableInfo]>
@@ -101,8 +51,6 @@ final class SidebarViewModel {
     // MARK: - Dependencies
 
     private let connectionId: UUID
-    private let tableFetcher: TableFetcher
-    private var loadTask: Task<Void, Never>?
 
     // MARK: - Convenience Accessors
 
@@ -140,9 +88,7 @@ final class SidebarViewModel {
         pendingDeletes: Binding<Set<String>>,
         tableOperationOptions: Binding<[String: TableOperationOptions]>,
         databaseType: DatabaseType,
-        connectionId: UUID,
-        schemaProvider: SQLSchemaProvider? = nil,
-        tableFetcher: TableFetcher? = nil
+        connectionId: UUID
     ) {
         self.tablesBinding = tables
         self.selectedTablesBinding = selectedTables
@@ -151,94 +97,6 @@ final class SidebarViewModel {
         self.tableOperationOptionsBinding = tableOperationOptions
         self.databaseType = databaseType
         self.connectionId = connectionId
-        self.tableFetcher = tableFetcher ?? LiveTableFetcher(connectionId: connectionId, schemaProvider: schemaProvider)
-    }
-
-    // MARK: - Lifecycle
-
-    func onAppear() {
-        guard tables.isEmpty else {
-            sidebarLogger.debug("onAppear: tables not empty (\(self.tables.count)), skipping")
-            return
-        }
-        if DatabaseManager.shared.driver(for: connectionId) != nil {
-            sidebarLogger.debug("onAppear: loading tables")
-            loadTables()
-        } else {
-            sidebarLogger.warning("onAppear: driver is nil for \(self.connectionId)")
-        }
-    }
-
-    // MARK: - Table Loading
-
-    func loadTables(force: Bool = false) {
-        loadTask?.cancel()
-        guard !isLoading else { return }
-        isLoading = true
-        errorMessage = nil
-        loadTask = Task {
-            await loadTablesAsync(force: force)
-        }
-    }
-
-    func forceLoadTables() {
-        loadTask?.cancel()
-        loadTask = nil
-        isLoading = false
-        loadTables(force: true)
-    }
-
-    private func loadTablesAsync(force: Bool = false) async {
-        let previousSelectedName: String? = tables.isEmpty ? nil : selectedTables.first?.name
-
-        do {
-            let fetchedTables = try await tableFetcher.fetchTables(force: force)
-            tables = fetchedTables
-
-            // Clean up stale entries for tables that no longer exist
-            let fetchedNames = Set(fetchedTables.map(\.name))
-
-            let staleSelections = selectedTables.filter { !fetchedNames.contains($0.name) }
-            if !staleSelections.isEmpty {
-                isRestoringSelection = true
-                selectedTables.subtract(staleSelections)
-                isRestoringSelection = false
-            }
-
-            let stalePendingDeletes = pendingDeletes.subtracting(fetchedNames)
-            let stalePendingTruncates = pendingTruncates.subtracting(fetchedNames)
-            if !stalePendingDeletes.isEmpty {
-                pendingDeletes.subtract(stalePendingDeletes)
-                for name in stalePendingDeletes {
-                    tableOperationOptions.removeValue(forKey: name)
-                }
-            }
-            if !stalePendingTruncates.isEmpty {
-                pendingTruncates.subtract(stalePendingTruncates)
-                for name in stalePendingTruncates {
-                    tableOperationOptions.removeValue(forKey: name)
-                }
-            }
-
-            // Only restore selection if it was cleared (prevent reopening tabs)
-            if let name = previousSelectedName {
-                let currentNames = Set(selectedTables.map { $0.name })
-                if !currentNames.contains(name) {
-                    // Selection was cleared, restore it without triggering callback
-                    isRestoringSelection = true
-                    if let restored = fetchedTables.first(where: { $0.name == name }) {
-                        selectedTables = [restored]
-                    }
-                    isRestoringSelection = false
-                }
-            }
-            isLoading = false
-        } catch is CancellationError {
-            isLoading = false
-        } catch {
-            errorMessage = error.localizedDescription
-            isLoading = false
-        }
     }
 
     // MARK: - Batch Operations

TablePro/Views/Main/Extensions/MainContentCoordinator+Discard.swift

@@ -80,6 +80,6 @@ extension MainContentCoordinator {
             tabManager.tabs[index].pendingChanges = TabPendingChanges()
         }
 
-        reloadSidebar()
+        Task { await refreshTables() }
     }
 }