refactor: ValidationDisplayUiHelper for Getting Started summaries

docs/knowledgebase/gui-architecture-deferred.md

@@ -62,6 +62,7 @@ Plans: `docs/plans/2026-06-03-012`, `021`–`029`, `033`–`057`. Surface refere
 | Directory picker init/sync → `SettingsService` | Done | plan `075`, PR #123 |
 | Mod context menu + global flyout → `MenuBuilderService` | Done | plan `072`, PR #130 |
 
+**Headless tests:** `dotnet test src/ModSync.Tests/ModSync.Tests.csproj --filter SettingsService` (plan `077`); `--filter MenuBuilderService` (plan `072`); `--filter ValidationDisplayUiHelper` (plan `094`).
 **Headless tests:** `dotnet test src/ModSync.Tests/ModSync.Tests.csproj --filter SettingsService` (plan `077`); `--filter MenuBuilderService` (plan `072`); `--filter DownloadOrchestrationService` (plan `088`).
 **Headless tests:** `dotnet test src/ModSync.Tests/ModSync.Tests.csproj --filter SettingsService` (plan `077`); `--filter MenuBuilderService` (plan `072`); `--filter DialogServiceTests` / `FileSystemServiceTests` (plan `113`).
 **Headless tests:** `dotnet test src/ModSync.Tests/ModSync.Tests.csproj --filter SettingsService` (plan `077`); `--filter MenuBuilderService` (plan `072`); `--filter FilterItemModel` (plan `112`).

docs/plans/2026-06-04-094-refactor-validation-display-ui-helper-plan.md

@@ -0,0 +1,19 @@
+---
+title: "refactor: ValidationDisplayUiHelper for Getting Started summaries"
+status: shipped
+pr: pending
+---
+
+# refactor: ValidationDisplayUiHelper for Getting Started summaries
+
+## Problem
+
+`ValidationDisplayService` duplicated validation summary strings and error-navigation bounds inline in Getting Started validation UI.
+
+## Solution
+
+Add `ValidationDisplayUiHelper` for summary/error-counter formatting, invalid-component collection, and navigation bounds; wire `ValidationDisplayService` to delegate.
+
+## Verification
+
+`dotnet test src/ModSync.Tests/ModSync.Tests.csproj --filter ValidationDisplayUiHelper`

src/ModSync.GUI/Services/ValidationDisplayService.cs

@@ -47,14 +47,8 @@ public void ShowValidationResults(
                 List<ModComponent> mainComponents = _getMainComponents();
                 var selectedComponents = mainComponents.Where(c => c.IsSelected).ToList();
                 _validationErrors.Clear();
-
-                foreach (ModComponent component in selectedComponents)
-                {
-                    if (!isComponentValid(component))
-                    {
-                        _validationErrors.Add(component);
-                    }
-                }
+                _validationErrors.AddRange(
+                    ValidationDisplayUiHelper.CollectInvalidSelectedComponents(selectedComponents, isComponentValid));
 
                 if (validationResultsArea is null)
                 {
@@ -68,7 +62,7 @@ public void ShowValidationResults(
 
                     if (validationSummaryText != null)
                     {
-                        validationSummaryText.Text = $"✅ All {selectedComponents.Count} mods validated successfully!";
+                        validationSummaryText.Text = ValidationDisplayUiHelper.FormatAllValidSummary(selectedComponents.Count);
                     }
 
                     if (errorNavigationArea != null)
@@ -92,7 +86,9 @@ public void ShowValidationResults(
                     int validCount = selectedComponents.Count - _validationErrors.Count;
                     if (validationSummaryText != null)
                     {
-                        validationSummaryText.Text = $"⚠️ {validCount}/{selectedComponents.Count} mods validated successfully";
+                        validationSummaryText.Text = ValidationDisplayUiHelper.FormatPartialValidSummary(
+                            validCount,
+                            selectedComponents.Count);
                     }
 
                     if (errorNavigationArea != null)
@@ -161,7 +157,9 @@ public void UpdateErrorDisplay(
 
                 if (errorCounterText != null)
                 {
-                    errorCounterText.Text = $"Error {_currentErrorIndex + 1} of {_validationErrors.Count}";
+                    errorCounterText.Text = ValidationDisplayUiHelper.FormatErrorCounter(
+                        _currentErrorIndex,
+                        _validationErrors.Count);
                 }
 
                 if (errorModNameText != null)
@@ -171,12 +169,14 @@ public void UpdateErrorDisplay(
 
                 if (prevErrorButton != null)
                 {
-                    prevErrorButton.IsEnabled = _currentErrorIndex > 0;
+                    prevErrorButton.IsEnabled = ValidationDisplayUiHelper.CanNavigateToPreviousError(_currentErrorIndex);
                 }
 
                 if (nextErrorButton != null)
                 {
-                    nextErrorButton.IsEnabled = _currentErrorIndex < _validationErrors.Count - 1;
+                    nextErrorButton.IsEnabled = ValidationDisplayUiHelper.CanNavigateToNextError(
+                        _currentErrorIndex,
+                        _validationErrors.Count);
                 }
 
                 (string ErrorType, string Description, bool CanAutoFix) = _validationService.GetComponentErrorDetails(currentError);
@@ -211,7 +211,7 @@ public void NavigateToPreviousError(
             Button prevErrorButton,
             Button nextErrorButton)
         {
-            if (_currentErrorIndex > 0)
+            if (ValidationDisplayUiHelper.CanNavigateToPreviousError(_currentErrorIndex))
             {
                 _currentErrorIndex--;
                 UpdateErrorDisplay(
@@ -234,7 +234,7 @@ public void NavigateToNextError(
             Button prevErrorButton,
             Button nextErrorButton)
         {
-            if (_currentErrorIndex < _validationErrors.Count - 1)
+            if (ValidationDisplayUiHelper.CanNavigateToNextError(_currentErrorIndex, _validationErrors.Count))
             {
                 _currentErrorIndex++;
                 UpdateErrorDisplay(

src/ModSync.GUI/Services/ValidationDisplayUiHelper.cs

@@ -0,0 +1,53 @@
+// Copyright 2021-2025 ModSync
+// Licensed under the Business Source License 1.1 (BSL 1.1).
+// See LICENSE.txt file in the project root for full license information.
+
+using System;
+using System.Collections.Generic;
+using ModSync.Core;
+
+namespace ModSync.Services
+{
+    public static class ValidationDisplayUiHelper
+    {
+        public static string FormatAllValidSummary(int selectedCount) =>
+            $"✅ All {selectedCount} mods validated successfully!";
+
+        public static string FormatPartialValidSummary(int validCount, int selectedCount) =>
+            $"⚠️ {validCount}/{selectedCount} mods validated successfully";
+
+        public static string FormatErrorCounter(int currentIndex, int totalErrors) =>
+            $"Error {currentIndex + 1} of {totalErrors}";
+
+        public static List<ModComponent> CollectInvalidSelectedComponents(
+            IEnumerable<ModComponent> selectedComponents,
+            Func<ModComponent, bool> isComponentValid)
+        {
+            if (selectedComponents is null)
+            {
+                throw new ArgumentNullException(nameof(selectedComponents));
+            }
+
+            if (isComponentValid is null)
+            {
+                throw new ArgumentNullException(nameof(isComponentValid));
+            }
+
+            var validationErrors = new List<ModComponent>();
+            foreach (ModComponent component in selectedComponents)
+            {
+                if (!isComponentValid(component))
+                {
+                    validationErrors.Add(component);
+                }
+            }
+
+            return validationErrors;
+        }
+
+        public static bool CanNavigateToPreviousError(int currentErrorIndex) => currentErrorIndex > 0;
+
+        public static bool CanNavigateToNextError(int currentErrorIndex, int errorCount) =>
+            currentErrorIndex < errorCount - 1;
+    }
+}

src/ModSync.Tests/ValidationDisplayUiHelperTests.cs

@@ -0,0 +1,72 @@
+// Copyright 2021-2025 ModSync
+// Licensed under the Business Source License 1.1 (BSL 1.1).
+// See LICENSE.txt file in the project root for full license information.
+
+using System;
+using System.Collections.Generic;
+using ModSync.Core;
+using ModSync.Services;
+using Xunit;
+
+namespace ModSync.Tests
+{
+    public sealed class ValidationDisplayUiHelperTests
+    {
+        [Fact(DisplayName = "FormatAllValidSummary uses success phrasing")]
+        public void FormatAllValidSummary_UsesSuccessPhrasing()
+        {
+            Assert.Equal("✅ All 3 mods validated successfully!", ValidationDisplayUiHelper.FormatAllValidSummary(3));
+        }
+
+        [Fact(DisplayName = "FormatPartialValidSummary uses warning ratio phrasing")]
+        public void FormatPartialValidSummary_UsesWarningRatio()
+        {
+            Assert.Equal(
+                "⚠️ 2/5 mods validated successfully",
+                ValidationDisplayUiHelper.FormatPartialValidSummary(validCount: 2, selectedCount: 5));
+        }
+
+        [Fact(DisplayName = "FormatErrorCounter uses one-based index")]
+        public void FormatErrorCounter_UsesOneBasedIndex()
+        {
+            Assert.Equal("Error 2 of 4", ValidationDisplayUiHelper.FormatErrorCounter(currentIndex: 1, totalErrors: 4));
+        }
+
+        [Fact(DisplayName = "CollectInvalidSelectedComponents returns only failing mods")]
+        public void CollectInvalidSelectedComponents_ReturnsInvalidOnly()
+        {
+            var components = new List<ModComponent>
+            {
+                new ModComponent { Name = "Valid" },
+                new ModComponent { Name = "Invalid" },
+            };
+
+            List<ModComponent> errors = ValidationDisplayUiHelper.CollectInvalidSelectedComponents(
+                components,
+                component => string.Equals(component.Name, "Valid", StringComparison.Ordinal));
+
+            Assert.Single(errors);
+            Assert.Equal("Invalid", errors[0].Name);
+        }
+
+        [Fact(DisplayName = "Navigation helpers respect bounds")]
+        public void NavigationHelpers_RespectBounds()
+        {
+            Assert.False(ValidationDisplayUiHelper.CanNavigateToPreviousError(0));
+            Assert.True(ValidationDisplayUiHelper.CanNavigateToPreviousError(1));
+            Assert.True(ValidationDisplayUiHelper.CanNavigateToNextError(0, errorCount: 3));
+            Assert.False(ValidationDisplayUiHelper.CanNavigateToNextError(2, errorCount: 3));
+        }
+
+        [Fact(DisplayName = "CollectInvalidSelectedComponents rejects null inputs")]
+        public void CollectInvalidSelectedComponents_RejectsNullInputs()
+        {
+            Assert.Throws<ArgumentNullException>(() =>
+                ValidationDisplayUiHelper.CollectInvalidSelectedComponents(null, _ => true));
+            Assert.Throws<ArgumentNullException>(() =>
+                ValidationDisplayUiHelper.CollectInvalidSelectedComponents(
+                    new List<ModComponent>(),
+                    null));
+        }
+    }
+}