fix(html): fix comment detection in Astro frontmatter (#7989)

Co-authored-by: Emanuele Stoppa <[email protected]>

Author: alissonlauffer

.changeset/fix-astro-frontmatter-comments.md

@@ -0,0 +1,12 @@
+---
+"@biomejs/biome": patch
+---
+
+Fixed a regression in Astro frontmatter parsing where comments inside quoted strings were incorrectly detected as actual comments. This caused the parser to prematurely terminate frontmatter parsing when encountering strings like `const test = "//";`.
+For example, the following Astro frontmatter now parses correctly:
+
+```astro
+---
+const test = "// not a real comment";
+---
+```

crates/biome_html_parser/src/lexer/mod.rs

@@ -1056,8 +1056,13 @@ impl QuotesSeen {
             return; // Don't track quotes inside comments
         }
 
-        // Check for comment entry
-        if self.prev_byte == Some(b'/') && (byte == b'/' || byte == b'*') {
+        // Check for comment entry - but only if we're not inside quotes
+        if self.prev_byte == Some(b'/')
+            && (byte == b'/' || byte == b'*')
+            && self.single == 0
+            && self.double == 0
+            && self.template == 0
+        {
             self.inside_comment = true;
             self.prev_byte = Some(byte);
             return;

crates/biome_html_parser/tests/html_specs/ok/astro/comment_in_frontmatter.astro

@@ -0,0 +1,5 @@
+---
+const test = "//";
+---
+
+<div>{test}</div>

crates/biome_html_parser/tests/html_specs/ok/astro/comment_in_frontmatter.astro.snap

@@ -0,0 +1,96 @@
+---
+source: crates/biome_html_parser/tests/spec_test.rs
+expression: snapshot
+---
+## Input
+
+```astro
+---
+const test = "//";
+---
+
+<div>{test}</div>
+
+```
+
+
+## AST
+
+```
+HtmlRoot {
+    bom_token: missing (optional),
+    frontmatter: AstroFrontmatterElement {
+        l_fence_token: FENCE@0..3 "---" [] [],
+        content: AstroEmbeddedContent {
+            content_token: HTML_LITERAL@3..23 "const test = \"//\";\n" [Newline("\n")] [],
+        },
+        r_fence_token: FENCE@23..26 "---" [] [],
+    },
+    directive: missing (optional),
+    html: HtmlElementList [
+        HtmlElement {
+            opening_element: HtmlOpeningElement {
+                l_angle_token: L_ANGLE@26..29 "<" [Newline("\n"), Newline("\n")] [],
+                name: HtmlTagName {
+                    value_token: HTML_LITERAL@29..32 "div" [] [],
+                },
+                attributes: HtmlAttributeList [],
+                r_angle_token: R_ANGLE@32..33 ">" [] [],
+            },
+            children: HtmlElementList [
+                HtmlSingleTextExpression {
+                    l_curly_token: L_CURLY@33..34 "{" [] [],
+                    expression: HtmlTextExpression {
+                        html_literal_token: HTML_LITERAL@34..38 "test" [] [],
+                    },
+                    r_curly_token: R_CURLY@38..39 "}" [] [],
+                },
+            ],
+            closing_element: HtmlClosingElement {
+                l_angle_token: L_ANGLE@39..40 "<" [] [],
+                slash_token: SLASH@40..41 "/" [] [],
+                name: HtmlTagName {
+                    value_token: HTML_LITERAL@41..44 "div" [] [],
+                },
+                r_angle_token: R_ANGLE@44..45 ">" [] [],
+            },
+        },
+    ],
+    eof_token: EOF@45..46 "" [Newline("\n")] [],
+}
+```
+
+## CST
+
+```
+0: [email protected]
+  0: (empty)
+  1: [email protected]
+    0: [email protected] "---" [] []
+    1: [email protected]
+      0: [email protected] "const test = \"//\";\n" [Newline("\n")] []
+    2: [email protected] "---" [] []
+  2: (empty)
+  3: [email protected]
+    0: [email protected]
+      0: [email protected]
+        0: [email protected] "<" [Newline("\n"), Newline("\n")] []
+        1: [email protected]
+          0: [email protected] "div" [] []
+        2: [email protected]
+        3: [email protected] ">" [] []
+      1: [email protected]
+        0: [email protected]
+          0: [email protected] "{" [] []
+          1: HTML_TEXT_EXPRESSION@34..38
+            0: HTML_LITERAL@34..38 "test" [] []
+          2: R_CURLY@38..39 "}" [] []
+      2: HTML_CLOSING_ELEMENT@39..45
+        0: L_ANGLE@39..40 "<" [] []
+        1: SLASH@40..41 "/" [] []
+        2: HTML_TAG_NAME@41..44
+          0: HTML_LITERAL@41..44 "div" [] []
+        3: R_ANGLE@44..45 ">" [] []
+  4: EOF@45..46 "" [Newline("\n")] []
+
+```