feat(fmt/md): ordered lists and space normalization

.claude/skills/formatter-development/SKILL.md

@@ -1,6 +1,6 @@
 ---
 name: formatter-development
-description: Guide for implementing formatting rules using Biome's IR-based formatter infrastructure. Use when implementing formatting for new syntax nodes, handling comments in formatted output, or comparing Biome's formatting against Prettier for JavaScript, CSS, JSON, HTML, or other languages.
+description: Guide for implementing formatting rules using Biome's IR-based formatter infrastructure. Use when implementing formatting for new syntax nodes, handling comments in formatted output, writing or debugging formatter snapshot tests, diagnosing idempotency failures, or comparing Biome's formatting against Prettier for JavaScript, CSS, JSON, HTML, Markdown, or other languages.
 compatibility: Designed for coding agents working on the Biome codebase (github.com/biomejs/biome).
 ---
 
@@ -156,6 +156,60 @@ echo 'const x = 1' | bun packages/prettier-compare/bin/prettier-compare.js --reb
 
 **Always use `--rebuild`** to ensure WASM bundle matches your Rust changes.
 
+### Format and Build
+
+After changes:
+
+```shell
+just f              # Format Rust code
+just l              # Lint
+just gen-formatter  # Regenerate formatter infrastructure if needed
+```
+
+## Testing infrastructure
+
+The testing infrastructure of the formatters is divided in two main pieces. Internal and external.
+
+The testing infrastructure is designed for catching idempotency cases, which means that each file inside the infrastructure is designed to fail if:
+- the final **printed** output differs on a second formatting run.
+- the final **IR** output differs on a second formatting run.
+
+**Both must be fixed.**
+
+Run `cargo t` twice. The first run may write or update snapshots; the second run re-formats the just-written output and confirms it is stable. Skipping the second run hides idempotency bugs — a broken formatter can look green on a single pass because the snapshot it wrote matches itself.
+
+### `quick_test.rs`
+
+- Use `quick_test.rs` inside the crate for testing theories and formatting.
+- Only modify the `source` string literal inside the test. Do not change the parse/format/assert scaffolding around it — that scaffolding already verifies idempotency and prints the CST and IR you need for debugging.
+
+### External infra
+
+The external infra relies on a human pulling the tests inside the repository, inside the folder `<crate>/tests/prettier`.
+
+Once the tests are ported, the infrastructure produces two files for each original file:
+- `<file_name>.<ext>.prettier-snap` which contains the output generated by Prettier at the moment the test was ported.
+- `<file_name>.<ext>.snap` which contains three sections
+  - the input source
+  - the list of diffs between Prettier and Biome
+  - the output generated by Biome
+
+The `.snap` file is only created when Biome's output differs from Prettier's. When the two agree, no `.snap` file is written.
+
+The absence of a `.snap` file is **positive** — it means Biome matches Prettier for that input.
+
+### Internal infrastructure
+
+The internal infrastructure relies on creating new test files. For each test, place two snippets in the same file:
+- a piece of source code **already formatted** the way Biome should produce it
+- the same code in an **unformatted** shape
+
+After running the formatter, both snippets should produce identical output. That identity proves the formatter converges on a canonical form and is idempotent.
+
+**Always create new test cases when implementing a feature or fixing a bug.** Internal tests exercise the exact shape you care about and survive even if the Prettier corpus changes.
+
+**Do not rely on Prettier `.snap` files disappearing as proof of correctness.** A missing `.snap` only means Biome and Prettier agree on that specific ported input. It does not cover the edge cases you introduced — write internal tests for those, and do not delete a Prettier `.snap` to make a diff "go away".
+
 ### Create Snapshot Tests
 
 Create test files in `tests/specs/` organized by feature:
@@ -219,16 +273,6 @@ Create `options.json` in the test folder:
 
 This applies to all test files in that folder.
 
-### Format and Build
-
-After changes:
-
-```shell
-just f              # Format Rust code
-just l              # Lint
-just gen-formatter  # Regenerate formatter infrastructure if needed
-```
-
 ## Tips
 
 - **format_verbatim_node**: Initial generated code uses this - replace it with proper IR as you implement formatting

.gitignore

@@ -25,6 +25,8 @@ dhat-heap.json
 /crates/biome_css_formatter/report.*
 /crates/biome_graphql_formatter/report.*
 /crates/biome_js_formatter/report.*
+/crates/biome_markdown_formatter/report.*
+/crates/biome_html_formatter/report.*
 /crates/biome_json_formatter/report.*
 /crates/biome_json_formatter/report_incompatible.*
 

crates/biome_html_formatter/src/html/any/attribute_initializer.rs

@@ -1,32 +1,17 @@
 //! This is a generated file. Don't modify it by hand! Run 'cargo codegen formatter' to re-generate the file.
 
 use crate::prelude::*;
-use biome_formatter::FormatRuleWithOptions;
 use biome_html_syntax::AnyHtmlAttributeInitializer;
 #[derive(Debug, Clone, Default)]
-pub(crate) struct FormatAnyHtmlAttributeInitializer {
-    compact: bool,
-}
-
+pub(crate) struct FormatAnyHtmlAttributeInitializer;
 impl FormatRule<AnyHtmlAttributeInitializer> for FormatAnyHtmlAttributeInitializer {
     type Context = HtmlFormatContext;
     fn fmt(&self, node: &AnyHtmlAttributeInitializer, f: &mut HtmlFormatter) -> FormatResult<()> {
         match node {
             AnyHtmlAttributeInitializer::HtmlAttributeSingleTextExpression(node) => {
-                node.format().with_options(self.compact).fmt(f)
-            }
-            AnyHtmlAttributeInitializer::HtmlString(node) => {
-                node.format().with_options(self.compact).fmt(f)
+                node.format().fmt(f)
             }
+            AnyHtmlAttributeInitializer::HtmlString(node) => node.format().fmt(f),
         }
     }
 }
-
-impl FormatRuleWithOptions<AnyHtmlAttributeInitializer> for FormatAnyHtmlAttributeInitializer {
-    type Options = bool;
-
-    fn with_options(mut self, options: Self::Options) -> Self {
-        self.compact = options;
-        self
-    }
-}

crates/biome_html_formatter/src/html/auxiliary/attribute_initializer_clause.rs

@@ -1,6 +1,7 @@
 use std::fmt::Debug;
 
 use crate::prelude::*;
+use crate::shared::FmtAnyAttributeInitializer;
 use biome_formatter::{CstFormatContext, FormatRuleWithOptions, write};
 use biome_html_syntax::{
     AnyHtmlAttributeInitializer, HtmlAttributeInitializerClause,
@@ -155,10 +156,11 @@ impl FormatNodeRule<HtmlAttributeInitializerClause> for FormatHtmlAttributeIniti
             CompactKind::Remove => {
                 let eq_token = eq_token.clone()?;
                 let value = value.clone()?;
-                write!(
-                    f,
-                    [format_removed(&eq_token), value.format().with_options(true),]
-                )?;
+                let fmt = FmtAnyAttributeInitializer {
+                    node: value,
+                    compact: true,
+                };
+                write!(f, [format_removed(&eq_token), &fmt,])?;
                 Ok(())
             }
         }

crates/biome_html_formatter/src/lib.rs

@@ -21,6 +21,7 @@ mod generated;
 mod html;
 pub(crate) mod prelude;
 pub(crate) mod separated;
+pub(crate) mod shared;
 mod svelte;
 mod trivia;
 pub mod utils;

crates/biome_html_formatter/src/shared.rs

@@ -0,0 +1,42 @@
+use crate::AsFormat;
+use crate::context::HtmlFormatContext;
+use biome_formatter::formatter::Formatter;
+use biome_formatter::{Format, FormatResult};
+use biome_html_syntax::{AnyHtmlAttributeInitializer, AnySvelteBindingProperty};
+
+pub(crate) struct FmtAnyAttributeInitializer {
+    pub(crate) node: AnyHtmlAttributeInitializer,
+    pub(crate) compact: bool,
+}
+
+impl Format<HtmlFormatContext> for FmtAnyAttributeInitializer {
+    fn fmt(&self, f: &mut Formatter<HtmlFormatContext>) -> FormatResult<()> {
+        match &self.node {
+            AnyHtmlAttributeInitializer::HtmlAttributeSingleTextExpression(node) => {
+                node.format().with_options(self.compact).fmt(f)
+            }
+            AnyHtmlAttributeInitializer::HtmlString(node) => {
+                node.format().with_options(self.compact).fmt(f)
+            }
+        }
+    }
+}
+
+pub(crate) struct FmtAnySvelteBindingProperty {
+    pub(crate) node: AnySvelteBindingProperty,
+    pub(crate) compact: bool,
+}
+
+impl Format<HtmlFormatContext> for FmtAnySvelteBindingProperty {
+    fn fmt(&self, f: &mut Formatter<HtmlFormatContext>) -> FormatResult<()> {
+        match &self.node {
+            AnySvelteBindingProperty::SvelteLiteral(node) => {
+                node.format().with_options(self.compact).fmt(f)
+            }
+            AnySvelteBindingProperty::SvelteMemberProperty(node) => node.format().fmt(f),
+            AnySvelteBindingProperty::SvelteName(node) => {
+                node.format().with_options(self.compact).fmt(f)
+            }
+        }
+    }
+}

crates/biome_html_formatter/src/svelte/any/binding_property.rs

@@ -1,34 +1,16 @@
 //! This is a generated file. Don't modify it by hand! Run 'cargo codegen formatter' to re-generate the file.
 
 use crate::prelude::*;
-use biome_formatter::FormatRuleWithOptions;
 use biome_html_syntax::AnySvelteBindingProperty;
 #[derive(Debug, Clone, Default)]
-pub(crate) struct FormatAnySvelteBindingProperty {
-    /// Whether it should be formatted in compact mode. In compact mode, all tokens and children
-    /// are removed
-    pub compact: bool,
-}
+pub(crate) struct FormatAnySvelteBindingProperty;
 impl FormatRule<AnySvelteBindingProperty> for FormatAnySvelteBindingProperty {
     type Context = HtmlFormatContext;
     fn fmt(&self, node: &AnySvelteBindingProperty, f: &mut HtmlFormatter) -> FormatResult<()> {
         match node {
-            AnySvelteBindingProperty::SvelteLiteral(node) => {
-                node.format().with_options(self.compact).fmt(f)
-            }
+            AnySvelteBindingProperty::SvelteLiteral(node) => node.format().fmt(f),
             AnySvelteBindingProperty::SvelteMemberProperty(node) => node.format().fmt(f),
-            AnySvelteBindingProperty::SvelteName(node) => {
-                node.format().with_options(self.compact).fmt(f)
-            }
+            AnySvelteBindingProperty::SvelteName(node) => node.format().fmt(f),
         }
     }
 }
-
-impl FormatRuleWithOptions<AnySvelteBindingProperty> for FormatAnySvelteBindingProperty {
-    type Options = bool;
-
-    fn with_options(mut self, options: Self::Options) -> Self {
-        self.compact = options;
-        self
-    }
-}

crates/biome_html_formatter/src/svelte/value/directive_value.rs

@@ -2,6 +2,7 @@ use crate::html::auxiliary::attribute_initializer_clause::{
     CompactKind, FormatHtmlAttributeInitializerClauseOptions,
 };
 use crate::prelude::*;
+use crate::shared::FmtAnySvelteBindingProperty;
 use biome_formatter::{FormatRuleWithOptions, write};
 use biome_html_syntax::{
     AnySvelteBindingProperty, SvelteDirectiveValue, SvelteDirectiveValueFields,
@@ -67,6 +68,10 @@ impl FormatSvelteDirectiveValue {
                 return Ok(false);
             }
 
+            let property = FmtAnySvelteBindingProperty {
+                node: property,
+                compact: true,
+            };
             write!(
                 f,
                 [
@@ -79,7 +84,7 @@ impl FormatSvelteDirectiveValue {
                             tag_name: None
                         }
                     ),
-                    property.format().with_options(true),
+                    &property,
                     modifiers.format().with_options(true)
                 ]
             )?;

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

@@ -22,7 +22,8 @@ impl FormatNodeRule<MdAutolink> for FormatMdAutolink {
                     .format()
                     .with_options(FormatMdFormatInlineItemListOptions {
                         print_mode: TextPrintMode::Trim(TrimMode::NormalizeWords),
-                        keep_fences_in_italics: false
+                        keep_fences_in_italics: false,
+                        inside_list: false,
                     }),
                 r_angle_token.format()
             ]

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

@@ -1,9 +1,12 @@
 use crate::markdown::auxiliary::list_marker_prefix::FormatMdListMarkerPrefixOptions;
+use crate::markdown::lists::block_list::FormatMdBlockListOptions;
 use crate::prelude::*;
+use crate::shared::TextPrintMode;
 use biome_formatter::write;
 use biome_markdown_syntax::{
     AnyMdBlock, AnyMdLeafBlock, MarkdownSyntaxKind, MdBullet, MdBulletFields,
 };
+
 #[derive(Debug, Clone, Default)]
 pub(crate) struct FormatMdBullet;
 impl FormatNodeRule<MdBullet> for FormatMdBullet {
@@ -19,6 +22,7 @@ impl FormatNodeRule<MdBullet> for FormatMdBullet {
         // but still format content through child formatters.
         let target_marker = if marker.kind() == MarkdownSyntaxKind::MINUS
             || first_block_is_dash_thematic_break(&content)
+            || marker.kind() == MarkdownSyntaxKind::MD_ORDERED_LIST_MARKER
         {
             None
         } else {
@@ -31,8 +35,13 @@ impl FormatNodeRule<MdBullet> for FormatMdBullet {
                 .format()
                 .with_options(FormatMdListMarkerPrefixOptions { target_marker })]
         )?;
-        content.format().fmt(f)?;
-        Ok(())
+        write!(
+            f,
+            [content.format().with_options(FormatMdBlockListOptions {
+                paragraph_print_mode: TextPrintMode::trim_keep_leading_spaces(),
+                trim: false,
+            })]
+        )
     }
 }
 

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

@@ -1,5 +1,6 @@
 use crate::markdown::lists::block_list::FormatMdBlockListOptions;
 use crate::prelude::*;
+use crate::shared::TextPrintMode;
 use biome_formatter::write;
 use biome_markdown_syntax::{MdDocument, MdDocumentFields};
 
@@ -20,9 +21,10 @@ impl FormatNodeRule<MdDocument> for FormatMdDocument {
         write!(
             f,
             [
-                value
-                    .format()
-                    .with_options(FormatMdBlockListOptions { trim: true }),
+                value.format().with_options(FormatMdBlockListOptions {
+                    paragraph_print_mode: TextPrintMode::Pristine,
+                    trim: true
+                }),
                 format_removed(&eof_token?)
             ]
         )?;