Case insensitive user text input comparison

src/Spectre.Console/Prompts/TextPrompt.cs

@@ -97,7 +97,15 @@ public sealed class TextPrompt<T> : IPrompt<T>, IHasCulture
     public TextPrompt(string prompt, StringComparer? comparer = null)
     {
         _prompt = prompt ?? throw new System.ArgumentNullException(nameof(prompt));
-        _comparer = comparer;
+
+        if (typeof(T) == typeof(string) && comparer is null)
+        {
+            _comparer = StringComparer.OrdinalIgnoreCase;
+        }
+        else
+        {
+            _comparer = comparer;
+        }
     }
 
     /// <summary>

src/Tests/Spectre.Console.Tests/Unit/Prompts/TextPromptTests.cs

@@ -410,4 +410,21 @@ public Task Uses_the_specified_choices_style()
         // Then
         return Verifier.Verify(console.Output);
     }
+
+    [Theory]
+    [InlineData("yes")]
+    [InlineData("Yes")]
+    [InlineData("YES")]
+    public async Task Uses_case_insensitive_comparison_when_no_comparer_is_passed(string input)
+    {
+        var console = new TestConsole { EmitAnsiSequences = true, };
+        console.Input.PushTextWithEnter(input);
+
+        var prompt = new TextPrompt<string>("Was the tool helpful?")
+            .AddChoices(["Yes", "Partially", "No"]);
+
+        var result = await console.PromptAsync(prompt);
+
+        Assert.Equal("Yes", result);
+    }
 }