refactor(Paginator): extract filtering of text input into Func

Sharprompt.Example/Program.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Linq;
 using System.Text;
 using System.Text.Json;
 
@@ -79,6 +80,7 @@ private static void RunSelectSample()
     private static void RunMultiSelectSample()
     {
         var options = Prompt.MultiSelect("Which cities would you like to visit?", new[] { "Seattle", "London", "Tokyo", "New York", "Singapore", "Shanghai" }, pageSize: 3, defaultValues: new[] { "Tokyo" });
+
         Console.WriteLine($"You picked {string.Join(", ", options)}");
     }
 

Sharprompt.Tests/PaginatorTests.cs

@@ -1,4 +1,5 @@
-using System.Linq;
+using System;
+using System.Linq;
 
 using Sharprompt.Internal;
 
@@ -8,10 +9,12 @@ namespace Sharprompt.Tests;
 
 public class PaginatorTests
 {
+    private readonly Func<int, string, bool> _containsTextInputFilter = (item, keyword) => item.ToString().Contains(keyword, StringComparison.OrdinalIgnoreCase);
+
     [Fact]
     public void Basic()
     {
-        var paginator = new Paginator<int>(Enumerable.Range(0, 20), 5, Optional<int>.Empty, x => x.ToString());
+        var paginator = new Paginator<int>(Enumerable.Range(0, 20), 5, Optional<int>.Empty, x => x.ToString(), _containsTextInputFilter);
 
         var currentItems1 = paginator.CurrentItems;
 
@@ -29,7 +32,7 @@ public void Basic()
     [Fact]
     public void Filter_NotEmpty()
     {
-        var paginator = new Paginator<int>(Enumerable.Range(0, 20), 5, Optional<int>.Empty, x => x.ToString());
+        var paginator = new Paginator<int>(Enumerable.Range(0, 20), 5, Optional<int>.Empty, x => x.ToString(), _containsTextInputFilter);
 
         paginator.UpdateFilter("0");
 
@@ -42,7 +45,7 @@ public void Filter_NotEmpty()
     [Fact]
     public void Filter_Empty()
     {
-        var paginator = new Paginator<int>(Enumerable.Range(0, 20), 5, Optional<int>.Empty, x => x.ToString());
+        var paginator = new Paginator<int>(Enumerable.Range(0, 20), 5, Optional<int>.Empty, x => x.ToString(), _containsTextInputFilter);
 
         paginator.UpdateFilter("x");
 
@@ -54,7 +57,7 @@ public void Filter_Empty()
     [Fact]
     public void SelectedItem()
     {
-        var paginator = new Paginator<int>(Enumerable.Range(0, 20), 5, Optional<int>.Empty, x => x.ToString());
+        var paginator = new Paginator<int>(Enumerable.Range(0, 20), 5, Optional<int>.Empty, x => x.ToString(), _containsTextInputFilter);
 
         paginator.NextPage();
         paginator.NextItem();
@@ -68,7 +71,7 @@ public void SelectedItem()
     [Fact]
     public void SelectedItem_NotSelected()
     {
-        var paginator = new Paginator<int>(Enumerable.Range(0, 20), 5, Optional<int>.Empty, x => x.ToString());
+        var paginator = new Paginator<int>(Enumerable.Range(0, 20), 5, Optional<int>.Empty, x => x.ToString(), _containsTextInputFilter);
 
         var selected = paginator.TryGetSelectedItem(out _);
 
@@ -78,7 +81,7 @@ public void SelectedItem_NotSelected()
     [Fact]
     public void SelectedItem_EmptyList()
     {
-        var paginator = new Paginator<int>(Enumerable.Range(0, 20), 5, Optional<int>.Empty, x => x.ToString());
+        var paginator = new Paginator<int>(Enumerable.Range(0, 20), 5, Optional<int>.Empty, x => x.ToString(), _containsTextInputFilter);
 
         paginator.UpdateFilter("x");
         paginator.NextItem();

Sharprompt/Forms/MultiSelectForm.cs

@@ -15,7 +15,7 @@ public MultiSelectForm(MultiSelectOptions<T> options)
         options.EnsureOptions();
 
         _options = options;
-        _paginator = new Paginator<T>(options.Items, Math.Min(options.PageSize, Height - 2), Optional<T>.Empty, options.TextSelector)
+        _paginator = new Paginator<T>(options.Items, Math.Min(options.PageSize, Height - 2), Optional<T>.Empty, options.TextSelector, options.TextInputFilter)
         {
             LoopingSelection = options.LoopingSelection
         };

Sharprompt/Forms/SelectForm.cs

@@ -14,7 +14,7 @@ public SelectForm(SelectOptions<T> options)
         options.EnsureOptions();
 
         _options = options;
-        _paginator = new Paginator<T>(options.Items, Math.Min(options.PageSize, Height - 2), Optional<T>.Create(options.DefaultValue), options.TextSelector)
+        _paginator = new Paginator<T>(options.Items, Math.Min(options.PageSize, Height - 2), Optional<T>.Create(options.DefaultValue), options.TextSelector, options.TextInputFilter)
         {
             LoopingSelection = options.LoopingSelection
         };

Sharprompt/Internal/Paginator.cs

@@ -8,17 +8,19 @@ namespace Sharprompt.Internal;
 
 internal class Paginator<T> : IEnumerable<T> where T : notnull
 {
-    public Paginator(IEnumerable<T> items, int pageSize, Optional<T> defaultValue, Func<T, string> textSelector)
+    public Paginator(IEnumerable<T> items, int pageSize, Optional<T> defaultValue, Func<T, string> textSelector, Func<T, string, bool> textInputFilter)
     {
         _items = items.ToArray();
         _pageSize = pageSize <= 0 ? _items.Length : Math.Min(pageSize, _items.Length);
         _textSelector = textSelector;
+        _filterFunc = textInputFilter;
 
         InitializeDefaults(defaultValue);
     }
 
     private readonly T[] _items;
     private readonly Func<T, string> _textSelector;
+    private readonly Func<T, string, bool> _filterFunc;
 
     private int _pageSize;
     private T[] _filteredItems = Array.Empty<T>();
@@ -144,8 +146,8 @@ public void UpdatePageSize(int newPageSize)
 
     private void UpdateFilteredItems()
     {
-        _filteredItems = _items.Where(x => _textSelector(x).IndexOf(FilterKeyword, StringComparison.OrdinalIgnoreCase) != -1)
-                               .ToArray();
+        _filteredItems = _items.Where(x => _filterFunc(x, FilterKeyword))
+            .ToArray();
 
         PageCount = (_filteredItems.Length - 1) / _pageSize + 1;
 

Sharprompt/MultiSelectOptions.cs

@@ -32,6 +32,8 @@ public MultiSelectOptions()
 
     public Func<T, string> TextSelector { get; set; } = x => x.ToString()!;
 
+    public Func<T, string, bool> TextInputFilter { get; set; } = (item, keyword) => item.ToString().Contains(keyword, StringComparison.OrdinalIgnoreCase);
+
     public Func<int, int, int, string> Pagination { get; set; } = (count, current, total) => string.Format(Resource.Message_Pagination, count, current, total);
 
     public bool LoopingSelection { get; set; } = true;

Sharprompt/Prompt.Basic.cs

@@ -106,7 +106,7 @@ public static T Select<T>(Action<SelectOptions<T>> configure) where T : notnull
         return Select(options);
     }
 
-    public static T Select<T>(string message, IEnumerable<T>? items = default, int pageSize = int.MaxValue, object? defaultValue = default, Func<T, string>? textSelector = default) where T : notnull
+    public static T Select<T>(string message, IEnumerable<T>? items = default, int pageSize = int.MaxValue, object? defaultValue = default, Func<T, string>? textSelector = default, Func<T, string, bool>? textInputFilter = default) where T : notnull
     {
         return Select<T>(options =>
         {
@@ -124,6 +124,11 @@ public static T Select<T>(string message, IEnumerable<T>? items = default, int p
             {
                 options.TextSelector = textSelector;
             }
+
+            if (textInputFilter is not null)
+            {
+                options.TextInputFilter = textInputFilter;
+            }
         });
     }
 
@@ -143,7 +148,9 @@ public static IEnumerable<T> MultiSelect<T>(Action<MultiSelectOptions<T>> config
         return MultiSelect(options);
     }
 
-    public static IEnumerable<T> MultiSelect<T>(string message, IEnumerable<T>? items = null, int pageSize = int.MaxValue, int minimum = 1, int maximum = int.MaxValue, IEnumerable<T>? defaultValues = default, Func<T, string>? textSelector = default) where T : notnull
+    public static IEnumerable<T> MultiSelect<T>(string message,
+        IEnumerable<T>? items = null, int pageSize = int.MaxValue, int minimum = 1, int maximum = int.MaxValue,
+        IEnumerable<T>? defaultValues = default, Func<T, string>? textSelector = default, Func<T, string, bool>? textInputFilter = default) where T : notnull
     {
         return MultiSelect<T>(options =>
         {
@@ -167,6 +174,11 @@ public static IEnumerable<T> MultiSelect<T>(string message, IEnumerable<T>? item
             {
                 options.TextSelector = textSelector;
             }
+
+            if (textInputFilter is not null)
+            {
+                options.TextInputFilter = textInputFilter;
+            }
         });
     }
 

Sharprompt/SelectOptions.cs

@@ -27,6 +27,8 @@ public SelectOptions()
 
     public Func<T, string> TextSelector { get; set; } = x => x.ToString()!;
 
+    public Func<T, string, bool> TextInputFilter { get; set; } = (item, keyword) => item.ToString().Contains(keyword, StringComparison.OrdinalIgnoreCase);
+
     public Func<int, int, int, string> Pagination { get; set; } = (count, current, total) => string.Format(Resource.Message_Pagination, count, current, total);
 
     public bool LoopingSelection { get; set; } = true;