fix: lowercase component member expressions in Astro/Svelte

.changeset/wet-dingos-spend.md

@@ -0,0 +1,5 @@
+---
+"@biomejs/biome": patch
+---
+
+Fixed Svelte/Astro lowercase component member expressions being formatted with extra space

crates/biome_html_formatter/tests/specs/html/astro/lowercase-member.astro

@@ -0,0 +1,9 @@
+---
+let form;
+let foo;
+let Data;
+---
+<form.Field></form.Field>
+<form.Field attr="value" />
+<Data.Client></Data.Client>
+<foo.Bar.Baz />

crates/biome_html_formatter/tests/specs/html/astro/lowercase-member.astro.snap

@@ -0,0 +1,59 @@
+---
+source: crates/biome_formatter_test/src/snapshot_builder.rs
+info: astro/lowercase-member.astro
+---
+
+# Input
+
+```astro
+---
+let form;
+let foo;
+let Data;
+---
+<form.Field></form.Field>
+<form.Field attr="value" />
+<Data.Client></Data.Client>
+<foo.Bar.Baz />
+
+```
+
+
+=============================
+
+# Outputs
+
+## Output 1
+
+-----
+Indent style: Tab
+Indent width: 2
+Line ending: LF
+Line width: 80
+Attribute Position: Auto
+Bracket same line: false
+Whitespace sensitivity: css
+Indent script and style: false
+Self close void elements: never
+Trailing newline: true
+-----
+
+```astro
+---
+let form;
+let foo;
+let Data;
+---
+
+<form.Field></form.Field>
+<form.Field attr="value" />
+<Data.Client></Data.Client>
+<foo.Bar.Baz />
+
+```
+
+
+
+## Unimplemented nodes/tokens
+
+"let form;\nlet foo;\nlet Data;\n-" => 4..34

crates/biome_html_formatter/tests/specs/html/svelte/lowercase-member.svelte

@@ -0,0 +1,4 @@
+<form.Field></form.Field>
+<form.Field attr="value" />
+<Data.Client></Data.Client>
+<foo.Bar.Baz />

crates/biome_html_formatter/tests/specs/html/svelte/lowercase-member.svelte.snap

@@ -0,0 +1,42 @@
+---
+source: crates/biome_formatter_test/src/snapshot_builder.rs
+info: svelte/lowercase-member.svelte
+---
+
+# Input
+
+```svelte
+<form.Field></form.Field>
+<form.Field attr="value" />
+<Data.Client></Data.Client>
+<foo.Bar.Baz />
+
+```
+
+
+=============================
+
+# Outputs
+
+## Output 1
+
+-----
+Indent style: Tab
+Indent width: 2
+Line ending: LF
+Line width: 80
+Attribute Position: Auto
+Bracket same line: false
+Whitespace sensitivity: css
+Indent script and style: false
+Self close void elements: never
+Trailing newline: true
+-----
+
+```svelte
+<form.Field></form.Field>
+<form.Field attr="value" />
+<Data.Client></Data.Client>
+<foo.Bar.Baz />
+
+```

crates/biome_html_parser/src/lexer/mod.rs

@@ -135,6 +135,7 @@ impl<'src> HtmlLexer<'src> {
             EXL => self.consume_byte(T![!]),
             // Handle colons as separate tokens for Astro directives
             COL => self.consume_byte(T![:]),
+            PRD => self.consume_byte(T![.]),
             BEO if self.at_svelte_opening_block() => self.consume_svelte_opening_block(),
             BEO => {
                 if self.at_opening_double_text_expression() {
@@ -283,6 +284,9 @@ impl<'src> HtmlLexer<'src> {
                 _ => {}
             }
         }
+        if dispatched == PRD {
+            return self.consume_byte(T![.]);
+        }
         self.consume_token_inside_tag(current)
     }
 

crates/biome_html_parser/src/syntax/mod.rs

@@ -190,11 +190,14 @@ fn parse_any_tag_name(p: &mut HtmlParser) -> ParsedSyntax {
     if !is_at_start_literal(p) {
         return Absent;
     }
-
     let tag_text = p.cur_text();
 
-    // Step 1: Parse base name (either component or regular tag)
-    let name = if is_possible_component(p, tag_text) {
+    // Check if this could be a component or has member expression
+    let is_component = is_possible_component(p, tag_text);
+    let has_member_expression = !p.options().is_html() && p.nth_at(1, T![.]);
+
+    // Step 1: Parse base name
+    let name = if is_component || has_member_expression {
         // Parse as component name - use component_name_context to allow `.` for member expressions
         let m = p.start();
         p.bump_with_context(HTML_LITERAL, component_name_context(p));
@@ -203,14 +206,18 @@ fn parse_any_tag_name(p: &mut HtmlParser) -> ParsedSyntax {
         // Parse as regular HTML tag
         parse_literal(p, HTML_TAG_NAME)
     };
-
-    // Step 2: Extend with member access if present (using .map() pattern from JSX parser)
+    // Step 2: Extend with member access if present
     name.map(|mut name| {
-        while p.at(T![.]) {
-            let m = name.precede(p); // Create marker BEFORE already-parsed name
-            p.bump_with_context(T![.], component_name_context(p)); // Use component context for `.`
+        // Check kind BEFORE moving name with precede()
+        let is_lowercase_tag = name.kind(p) == HTML_TAG_NAME;
 
-            // Parse member name - must use component_name_context to maintain `.` lexing
+        while p.at(T![.]) {
+            // Convert BEFORE precede takes ownership of name
+            if is_lowercase_tag {
+                name.change_kind(p, HTML_COMPONENT_NAME);
+            }
+            let m = name.precede(p);
+            p.bump_with_context(T![.], component_name_context(p));
             if is_at_start_literal(p) {
                 let member_m = p.start();
                 p.bump_with_context(HTML_LITERAL, component_name_context(p));
@@ -219,7 +226,7 @@ fn parse_any_tag_name(p: &mut HtmlParser) -> ParsedSyntax {
                 p.error(expected_element_name(p, p.cur_range()));
             }
 
-            name = m.complete(p, HTML_MEMBER_NAME); // Wrap previous name
+            name = m.complete(p, HTML_MEMBER_NAME);
         }
         name
     })