challenge(formatter): Attach comments to labels (#730)

crates/biome_js_formatter/src/comments.rs

@@ -208,8 +208,24 @@ fn handle_call_expression_comment(
 fn handle_continue_break_comment(
     comment: DecoratedComment<JsLanguage>,
 ) -> CommentPlacement<JsLanguage> {
+    // Make comments between `continue`/`break` and the label, leading comments of the label.
+    // ```javascript
+    // continue /* comment */ a;
+    // ```
+    if let Some(next) = comment.following_node() {
+        if next.kind() == JsSyntaxKind::JS_LABEL {
+            return CommentPlacement::leading(next.clone(), comment);
+        }
+    }
+
     let enclosing = comment.enclosing_node();
 
+    if let Some(preceding) = comment.preceding_node() {
+        if preceding.kind() == JsSyntaxKind::JS_LABEL {
+            return CommentPlacement::trailing(preceding.clone(), comment);
+        }
+    }
+
     // Make comments between the `continue` and label token trailing comments
     // ```javascript
     // continue /* comment */ a;

crates/biome_js_formatter/src/generated.rs

@@ -1510,6 +1510,29 @@ impl IntoFormat<JsFormatContext> for biome_js_syntax::JsVariableDeclarator {
         )
     }
 }
+impl FormatRule<biome_js_syntax::JsLabel> for crate::js::auxiliary::label::FormatJsLabel {
+    type Context = JsFormatContext;
+    #[inline(always)]
+    fn fmt(&self, node: &biome_js_syntax::JsLabel, f: &mut JsFormatter) -> FormatResult<()> {
+        FormatNodeRule::<biome_js_syntax::JsLabel>::fmt(self, node, f)
+    }
+}
+impl AsFormat<JsFormatContext> for biome_js_syntax::JsLabel {
+    type Format<'a> =
+        FormatRefWithRule<'a, biome_js_syntax::JsLabel, crate::js::auxiliary::label::FormatJsLabel>;
+    fn format(&self) -> Self::Format<'_> {
+        #![allow(clippy::default_constructed_unit_structs)]
+        FormatRefWithRule::new(self, crate::js::auxiliary::label::FormatJsLabel::default())
+    }
+}
+impl IntoFormat<JsFormatContext> for biome_js_syntax::JsLabel {
+    type Format =
+        FormatOwnedWithRule<biome_js_syntax::JsLabel, crate::js::auxiliary::label::FormatJsLabel>;
+    fn into_format(self) -> Self::Format {
+        #![allow(clippy::default_constructed_unit_structs)]
+        FormatOwnedWithRule::new(self, crate::js::auxiliary::label::FormatJsLabel::default())
+    }
+}
 impl FormatRule<biome_js_syntax::JsCaseClause>
     for crate::js::auxiliary::case_clause::FormatJsCaseClause
 {

crates/biome_js_formatter/src/js/any/label.rs

@@ -0,0 +1,12 @@
+//! 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_js_syntax::JsLabel;
+#[derive(Debug, Clone, Default)]
+pub(crate) struct FormatAnyJsLabel;
+impl FormatRule<AnyJsBinding> for FormatAnyJsLabel {
+    type Context = JsFormatContext;
+    fn fmt(&self, node: &JsLabel, f: &mut JsFormatter) -> FormatResult<()> {
+        node.format().fmt(f)
+    }
+}

crates/biome_js_formatter/src/js/auxiliary/label.rs

@@ -0,0 +1,11 @@
+use crate::prelude::*;
+use biome_formatter::write;
+use biome_js_syntax::{JsLabel, JsLabelFields};
+#[derive(Debug, Clone, Default)]
+pub(crate) struct FormatJsLabel;
+impl FormatNodeRule<JsLabel> for FormatJsLabel {
+    fn fmt_fields(&self, node: &JsLabel, f: &mut JsFormatter) -> FormatResult<()> {
+        let JsLabelFields { value_token } = node.as_fields();
+        write![f, [value_token.format()]]
+    }
+}

crates/biome_js_formatter/src/js/auxiliary/mod.rs

@@ -12,6 +12,7 @@ pub(crate) mod expression_snipped;
 pub(crate) mod finally_clause;
 pub(crate) mod function_body;
 pub(crate) mod initializer_clause;
+pub(crate) mod label;
 pub(crate) mod module;
 pub(crate) mod name;
 pub(crate) mod private_name;

crates/biome_js_formatter/src/js/statements/break_statement.rs

@@ -13,13 +13,13 @@ impl FormatNodeRule<JsBreakStatement> for FormatJsBreakStatement {
     fn fmt_fields(&self, node: &JsBreakStatement, f: &mut JsFormatter) -> FormatResult<()> {
         let JsBreakStatementFields {
             break_token,
-            label_token,
+            label,
             semicolon_token,
         } = node.as_fields();
 
         write!(f, [break_token.format()])?;
 
-        if let Some(label) = &label_token {
+        if let Some(label) = &label {
             write!(f, [space(), label.format()])?;
         }
 

crates/biome_js_formatter/src/js/statements/continue_statement.rs

@@ -13,13 +13,13 @@ impl FormatNodeRule<JsContinueStatement> for FormatJsContinueStatement {
     fn fmt_fields(&self, node: &JsContinueStatement, f: &mut JsFormatter) -> FormatResult<()> {
         let JsContinueStatementFields {
             continue_token,
-            label_token,
+            label,
             semicolon_token,
         } = node.as_fields();
 
         write!(f, [continue_token.format()])?;
 
-        if let Some(label) = &label_token {
+        if let Some(label) = &label {
             write!(f, [space(), label.format()])?;
         }
 

crates/biome_js_formatter/src/js/statements/labeled_statement.rs

@@ -10,12 +10,12 @@ pub(crate) struct FormatJsLabeledStatement;
 impl FormatNodeRule<JsLabeledStatement> for FormatJsLabeledStatement {
     fn fmt_fields(&self, node: &JsLabeledStatement, f: &mut JsFormatter) -> FormatResult<()> {
         let JsLabeledStatementFields {
-            label_token,
+            label,
             colon_token,
             body,
         } = node.as_fields();
 
-        write!(f, [label_token.format(), colon_token.format()])?;
+        write!(f, [label.format(), colon_token.format()])?;
 
         match body? {
             AnyJsStatement::JsEmptyStatement(empty) => {