Highlighted code blocks inside the app (#1153)

app/Tests/Tools/CodeHighlighting/CodeTokenKindExtensionsTests.cs

@@ -0,0 +1,21 @@
+using AIStudio.Tools;
+using AIStudio.Tools.CodeHighlighting;
+
+namespace AIStudio.Tests.Tools.CodeHighlighting;
+
+/// <summary>
+/// Checks that every kind of part takes its color from the style sheet of MudBlazor.Markdown, which
+/// colors the code blocks with the palette of the theme.
+/// </summary>
+[TestFixture]
+public sealed class CodeTokenKindExtensionsTests
+{
+    [Test]
+    public async Task EveryKindHasAClassWhichTheStyleSheetColors([Values] CodeTokenKind kind)
+    {
+        var styleSheet = await new WebRootFiles().ReadTextAsync("system/MudBlazor.Markdown/MudBlazor.Markdown.min.css");
+        var cssClass = kind.ToCssClass().Split(' ')[0];
+
+        Assert.That(styleSheet, Does.Contain($".{cssClass}"), "A library which renames its classes would leave this kind without color.");
+    }
+}