fix: color Markdown heading markers with heading text

src/syntax.rs

@@ -1263,6 +1263,25 @@ mod tests {
         assert_token(&cache, source, 3, "42", SyntaxKind::Number);
     }
 
+    #[test]
+    fn markdown_heading_markers_share_title_colors_without_coloring_plain_hashes() {
+        let source = "# One\n## Two\n### Three\n#### Four\n##### Five\n###### Six\n\nSetext\n======\n\nplain # text";
+        let cache = self::cache(source, "headings.md");
+        for row in 0..6 {
+            assert_token(
+                &cache,
+                source,
+                row,
+                &"#".repeat(row + 1),
+                SyntaxKind::Markup,
+            );
+        }
+        assert_token(&cache, source, 0, "One", SyntaxKind::Markup);
+        assert_token(&cache, source, 7, "Setext", SyntaxKind::Markup);
+        assert_token(&cache, source, 8, "======", SyntaxKind::Markup);
+        assert_eq!(kind_at(&cache, 10, 6), None);
+    }
+
     #[test]
     fn markdown_inline_and_fences_inject_known_languages_and_update_incrementally() {
         let original = "A **bold** and `code` link.\n\n```rust\nfn main() { let n = 42; }\n```\n\n```python\ndef hello():\n    return 7\n```\n\n```not-a-language\nfn not_rust() { 99; }\n```";