refactor(markdown-parser): promote pre-marker indent to explicit CST

crates/biome_markdown_formatter/src/generated.rs

@@ -1025,6 +1025,44 @@ impl IntoFormat<MarkdownFormatContext> for biome_markdown_syntax::MdQuote {
         )
     }
 }
+impl FormatRule<biome_markdown_syntax::MdQuoteIndent>
+    for crate::markdown::auxiliary::quote_indent::FormatMdQuoteIndent
+{
+    type Context = MarkdownFormatContext;
+    #[inline(always)]
+    fn fmt(
+        &self,
+        node: &biome_markdown_syntax::MdQuoteIndent,
+        f: &mut MarkdownFormatter,
+    ) -> FormatResult<()> {
+        FormatNodeRule::<biome_markdown_syntax::MdQuoteIndent>::fmt(self, node, f)
+    }
+}
+impl AsFormat<MarkdownFormatContext> for biome_markdown_syntax::MdQuoteIndent {
+    type Format<'a> = FormatRefWithRule<
+        'a,
+        biome_markdown_syntax::MdQuoteIndent,
+        crate::markdown::auxiliary::quote_indent::FormatMdQuoteIndent,
+    >;
+    fn format(&self) -> Self::Format<'_> {
+        FormatRefWithRule::new(
+            self,
+            crate::markdown::auxiliary::quote_indent::FormatMdQuoteIndent::default(),
+        )
+    }
+}
+impl IntoFormat<MarkdownFormatContext> for biome_markdown_syntax::MdQuoteIndent {
+    type Format = FormatOwnedWithRule<
+        biome_markdown_syntax::MdQuoteIndent,
+        crate::markdown::auxiliary::quote_indent::FormatMdQuoteIndent,
+    >;
+    fn into_format(self) -> Self::Format {
+        FormatOwnedWithRule::new(
+            self,
+            crate::markdown::auxiliary::quote_indent::FormatMdQuoteIndent::default(),
+        )
+    }
+}
 impl FormatRule<biome_markdown_syntax::MdQuotePrefix>
     for crate::markdown::auxiliary::quote_prefix::FormatMdQuotePrefix
 {
@@ -1454,6 +1492,31 @@ impl IntoFormat<MarkdownFormatContext> for biome_markdown_syntax::MdInlineItemLi
         )
     }
 }
+impl AsFormat<MarkdownFormatContext> for biome_markdown_syntax::MdQuoteIndentList {
+    type Format<'a> = FormatRefWithRule<
+        'a,
+        biome_markdown_syntax::MdQuoteIndentList,
+        crate::markdown::lists::quote_indent_list::FormatMdQuoteIndentList,
+    >;
+    fn format(&self) -> Self::Format<'_> {
+        FormatRefWithRule::new(
+            self,
+            crate::markdown::lists::quote_indent_list::FormatMdQuoteIndentList::default(),
+        )
+    }
+}
+impl IntoFormat<MarkdownFormatContext> for biome_markdown_syntax::MdQuoteIndentList {
+    type Format = FormatOwnedWithRule<
+        biome_markdown_syntax::MdQuoteIndentList,
+        crate::markdown::lists::quote_indent_list::FormatMdQuoteIndentList,
+    >;
+    fn into_format(self) -> Self::Format {
+        FormatOwnedWithRule::new(
+            self,
+            crate::markdown::lists::quote_indent_list::FormatMdQuoteIndentList::default(),
+        )
+    }
+}
 impl FormatRule<biome_markdown_syntax::MdBogus> for crate::markdown::bogus::bogus::FormatMdBogus {
     type Context = MarkdownFormatContext;
     #[inline(always)]

crates/biome_markdown_formatter/src/markdown/auxiliary/mod.rs

@@ -27,6 +27,7 @@ pub(crate) mod newline;
 pub(crate) mod ordered_list_item;
 pub(crate) mod paragraph;
 pub(crate) mod quote;
+pub(crate) mod quote_indent;
 pub(crate) mod quote_prefix;
 pub(crate) mod reference_image;
 pub(crate) mod reference_link;

crates/biome_markdown_formatter/src/markdown/auxiliary/quote_indent.rs

@@ -0,0 +1,10 @@
+use crate::prelude::*;
+use biome_markdown_syntax::MdQuoteIndent;
+use biome_rowan::AstNode;
+#[derive(Debug, Clone, Default)]
+pub(crate) struct FormatMdQuoteIndent;
+impl FormatNodeRule<MdQuoteIndent> for FormatMdQuoteIndent {
+    fn fmt_fields(&self, node: &MdQuoteIndent, f: &mut MarkdownFormatter) -> FormatResult<()> {
+        format_verbatim_node(node.syntax()).fmt(f)
+    }
+}

crates/biome_markdown_formatter/src/markdown/lists/mod.rs

@@ -5,3 +5,4 @@ pub(crate) mod bullet_list;
 pub(crate) mod code_name_list;
 pub(crate) mod hash_list;
 pub(crate) mod inline_item_list;
+pub(crate) mod quote_indent_list;

crates/biome_markdown_formatter/src/markdown/lists/quote_indent_list.rs

@@ -0,0 +1,10 @@
+use crate::prelude::*;
+use biome_markdown_syntax::MdQuoteIndentList;
+#[derive(Debug, Clone, Default)]
+pub(crate) struct FormatMdQuoteIndentList;
+impl FormatRule<MdQuoteIndentList> for FormatMdQuoteIndentList {
+    type Context = MarkdownFormatContext;
+    fn fmt(&self, node: &MdQuoteIndentList, f: &mut MarkdownFormatter) -> FormatResult<()> {
+        f.join().entries(node.iter().formatted()).finish()
+    }
+}

crates/biome_markdown_parser/src/syntax/mod.rs

@@ -69,6 +69,9 @@ pub(crate) const MAX_LINK_DESTINATION_PAREN_DEPTH: i32 = 32;
 const INDENT_CODE_BLOCK_SPACES: usize = 4;
 /// Tabs advance to the next 4-space tab stop in CommonMark parsing.
 const TAB_STOP_SPACES: usize = 4;
+/// CommonMark allows 0-3 spaces of optional indentation before block-level
+/// markers (blockquotes §5.1, list items §5.2/§5.3, ATX headings §4.2, etc.).
+pub(crate) const MAX_BLOCK_PREFIX_INDENT: usize = 3;
 
 pub(crate) fn parse_document(p: &mut MarkdownParser) {
     let m = p.start();

crates/biome_markdown_parser/src/syntax/quote.rs

@@ -41,7 +41,9 @@ use biome_parser::prelude::ParsedSyntax::{self, *};
 use crate::MarkdownParser;
 use crate::syntax::parse_any_block_with_indent_code_policy;
 use crate::syntax::parse_error::quote_nesting_too_deep;
-use crate::syntax::{INDENT_CODE_BLOCK_SPACES, TAB_STOP_SPACES, is_paragraph_like};
+use crate::syntax::{
+    INDENT_CODE_BLOCK_SPACES, MAX_BLOCK_PREFIX_INDENT, TAB_STOP_SPACES, is_paragraph_like,
+};
 
 /// Check if we're at the start of a block quote (`>`).
 pub(crate) fn at_quote(p: &mut MarkdownParser) -> bool {
@@ -55,10 +57,10 @@ pub(crate) fn at_quote(p: &mut MarkdownParser) -> bool {
             // Treat virtual line start as column 0.
             indent = 0;
         }
-        if indent > 3 {
+        if indent > MAX_BLOCK_PREFIX_INDENT {
             return false;
         }
-        p.skip_line_indent(3);
+        p.skip_line_indent(MAX_BLOCK_PREFIX_INDENT);
         p.at(T![>])
     })
 }
@@ -80,7 +82,7 @@ pub(crate) fn parse_quote(p: &mut MarkdownParser) -> ParsedSyntax {
         let range = p.cur_range();
         p.error(quote_nesting_too_deep(p, range, max_nesting_depth));
         p.state_mut().quote_depth_exceeded = true;
-        p.skip_line_indent(3);
+        p.skip_line_indent(MAX_BLOCK_PREFIX_INDENT);
         if p.at(T![>]) {
             p.parse_as_skipped_trivia_tokens(|p| p.bump(T![>]));
         } else if p.at(MD_TEXTUAL_LITERAL) && p.cur_text() == ">" {
@@ -127,16 +129,38 @@ fn emit_quote_prefix_node(p: &mut MarkdownParser) -> bool {
 ///
 /// Returns whether a post-marker separator was consumed.
 fn emit_quote_prefix_tokens(p: &mut MarkdownParser, use_virtual_line_start: bool) -> Option<bool> {
-    // TODO: Emit MD_QUOTE_PRE_MARKER_INDENT directly instead of skipping indent trivia.
-    // This is intentionally deferred from Step 1b to keep parser migration scope narrow.
     let saved_virtual = if use_virtual_line_start {
         let prev = p.state().virtual_line_start;
         p.state_mut().virtual_line_start = Some(p.cur_range().start());
         Some(prev)
     } else {
         None
     };
-    p.skip_line_indent(3);
+
+    // Direct bounded scan (0-3 cols per CommonMark §5.1): simpler than ParseNodeList
+    // here because we immediately validate `>` and keep this path no-recovery.
+    let indent_list_m = p.start();
+    let mut consumed = 0usize;
+    while p.at(MD_TEXTUAL_LITERAL) {
+        let text = p.cur_text();
+        if text.is_empty() || !text.chars().all(|c| c == ' ' || c == '\t') {
+            break;
+        }
+        // Tabs expand to tab-stop width (CommonMark §2.2).
+        let indent: usize = text
+            .chars()
+            .map(|c| if c == '\t' { TAB_STOP_SPACES } else { 1 })
+            .sum();
+        if consumed + indent > MAX_BLOCK_PREFIX_INDENT {
+            break;
+        }
+        consumed += indent;
+        let indent_m = p.start();
+        p.bump_remap(MD_QUOTE_PRE_MARKER_INDENT);
+        indent_m.complete(p, MD_QUOTE_INDENT);
+    }
+    indent_list_m.complete(p, MD_QUOTE_INDENT_LIST);
+
     if let Some(prev) = saved_virtual {
         p.state_mut().virtual_line_start = prev;
     }
@@ -311,7 +335,7 @@ pub(crate) fn line_has_quote_prefix_at_current(p: &MarkdownParser, depth: usize)
             }
             _ => break,
         }
-        if indent > 3 {
+        if indent > MAX_BLOCK_PREFIX_INDENT {
             return false;
         }
     }