feat(format/html): implement suppression comments

crates/biome_formatter/src/trivia.rs

@@ -78,7 +78,7 @@ where
                             let should_nestle =
                                 leading_comments_iter.peek().is_some_and(|next_comment| {
                                     should_nestle_adjacent_doc_comments(comment, next_comment)
-                                });
+                                }) || comment.piece().text().starts_with("<!--"); // HACK: we don't want to do this weird behavior to HTML comments.
 
                             write!(f, [maybe_space(!should_nestle)])?;
                         }
@@ -140,7 +140,7 @@ where
 
             let should_nestle = previous_comment.is_some_and(|previous_comment| {
                 should_nestle_adjacent_doc_comments(previous_comment, comment)
-            });
+            }) || comment.piece().text().starts_with("<!--"); // HACK: we don't want to do this weird behavior to HTML comments.
 
             // This allows comments at the end of nested structures:
             // {

crates/biome_formatter/src/verbatim.rs

@@ -41,6 +41,13 @@ pub struct FormatVerbatimNode<'node, L: Language> {
     format_comments: bool,
 }
 
+impl<L: Language> FormatVerbatimNode<'_, L> {
+    pub fn with_format_comments(mut self, format_comments: bool) -> Self {
+        self.format_comments = format_comments;
+        self
+    }
+}
+
 impl<Context> Format<Context> for FormatVerbatimNode<'_, Context::Language>
 where
     Context: CstFormatContext,

crates/biome_html_formatter/src/comments.rs

@@ -8,8 +8,8 @@ use biome_formatter::{
     prelude::*,
     write,
 };
-use biome_html_syntax::HtmlLanguage;
-use biome_rowan::{SyntaxTriviaPieceComments, TextLen};
+use biome_html_syntax::{HtmlClosingElement, HtmlLanguage, HtmlOpeningElement, HtmlSyntaxKind};
+use biome_rowan::{SyntaxNodeCast, SyntaxTriviaPieceComments, TextLen};
 use biome_suppression::parse_suppression_comment;
 
 use crate::context::HtmlFormatContext;
@@ -96,10 +96,81 @@ impl CommentStyle for HtmlCommentStyle {
         CommentKind::Block
     }
 
+    /// This allows us to override which comments are associated with which nodes.
+    ///
+    /// While every comment is directly attached to a **syntax token**, Biome actually builds a map of comments to **syntax nodes** separately. This map lives in [`HtmlComments`]. This is so that we can easily look up comments that are associated with a specific node. It's part of how suppression comments are handled.
+    ///
+    /// This method specifically, however, lets us fine tune which comments are associated with which nodes. This is useful when the default heuristic fails.
     fn place_comment(
         &self,
         comment: DecoratedComment<Self::Language>,
     ) -> CommentPlacement<Self::Language> {
+        // Fix trailing comments that are right before EOF being assigned to the wrong node.
+        //
+        // The issue is demonstrated in the example below.
+        // ```html
+        // Foo
+        //
+        // <!-- This comment gets assigned to the text node, despite it being actually attached to the EOF token. -->
+        // ```
+        if let Some(token) = comment.following_token() {
+            if token.kind() == HtmlSyntaxKind::EOF {
+                return CommentPlacement::trailing(comment.enclosing_node().clone(), comment);
+            }
+        }
+
+        // Fix trailing comments that should actually be leading comments for the next node.
+        // ```html
+        // 123<!--biome-ignore format: prettier ignore-->456
+        // ```
+        // This fix will ensure that the ignore comment is assigned to the 456 node instead of the 123 node.
+        if let Some(following_node) = comment.following_node() {
+            if comment.text_position().is_same_line() {
+                return CommentPlacement::leading(following_node.clone(), comment);
+            }
+        }
+        // match (comment.preceding_node(), comment.following_node()) {
+        //     (Some(preceding_node), Some(following_node)) => {
+        //         if preceding_node.kind() == HtmlSyntaxKind::HTML_CONTENT
+        //             && following_node.kind() == HtmlSyntaxKind::HTML_CONTENT
+        //         {
+        //             return CommentPlacement::leading(following_node.clone(), comment);
+        //         }
+
+        //         if matches!(
+        //             following_node.kind(),
+        //             HtmlSyntaxKind::HTML_CONTENT
+        //                 | HtmlSyntaxKind::HTML_ELEMENT
+        //                 | HtmlSyntaxKind::HTML_SELF_CLOSING_ELEMENT
+        //                 | HtmlSyntaxKind::HTML_BOGUS_ELEMENT
+        //         ) {
+        //             return CommentPlacement::leading(following_node.clone(), comment);
+        //         }
+        //     }
+        //     _ => {}
+        // }
+
+        // move leading comments placed on closing tags to trailing tags of previous siblings, or to be dangling if no siblings are present.
+        if let Some(_closing_tag) = comment
+            .following_node()
+            .and_then(|node| node.clone().cast::<HtmlClosingElement>())
+        {
+            if let Some(_preceding_opening_tag) = comment
+                .preceding_node()
+                .and_then(|node| node.clone().cast::<HtmlOpeningElement>())
+            {
+                return CommentPlacement::dangling(
+                    comment.preceding_node().unwrap().clone(),
+                    comment,
+                );
+            } else {
+                return CommentPlacement::trailing(
+                    comment.preceding_node().unwrap().clone(),
+                    comment,
+                );
+            }
+        }
+
         CommentPlacement::Default(comment)
     }
 }

crates/biome_html_formatter/src/generated.rs

@@ -189,44 +189,6 @@ impl IntoFormat<HtmlFormatContext> for biome_html_syntax::HtmlClosingElement {
         )
     }
 }
-impl FormatRule<biome_html_syntax::HtmlComment>
-    for crate::html::auxiliary::comment::FormatHtmlComment
-{
-    type Context = HtmlFormatContext;
-    #[inline(always)]
-    fn fmt(
-        &self,
-        node: &biome_html_syntax::HtmlComment,
-        f: &mut HtmlFormatter,
-    ) -> FormatResult<()> {
-        FormatNodeRule::<biome_html_syntax::HtmlComment>::fmt(self, node, f)
-    }
-}
-impl AsFormat<HtmlFormatContext> for biome_html_syntax::HtmlComment {
-    type Format<'a> = FormatRefWithRule<
-        'a,
-        biome_html_syntax::HtmlComment,
-        crate::html::auxiliary::comment::FormatHtmlComment,
-    >;
-    fn format(&self) -> Self::Format<'_> {
-        FormatRefWithRule::new(
-            self,
-            crate::html::auxiliary::comment::FormatHtmlComment::default(),
-        )
-    }
-}
-impl IntoFormat<HtmlFormatContext> for biome_html_syntax::HtmlComment {
-    type Format = FormatOwnedWithRule<
-        biome_html_syntax::HtmlComment,
-        crate::html::auxiliary::comment::FormatHtmlComment,
-    >;
-    fn into_format(self) -> Self::Format {
-        FormatOwnedWithRule::new(
-            self,
-            crate::html::auxiliary::comment::FormatHtmlComment::default(),
-        )
-    }
-}
 impl FormatRule<biome_html_syntax::HtmlContent>
     for crate::html::auxiliary::content::FormatHtmlContent
 {

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

@@ -10,7 +10,6 @@ impl FormatRule<AnyHtmlElement> for FormatAnyHtmlElement {
         match node {
             AnyHtmlElement::HtmlBogusElement(node) => node.format().fmt(f),
             AnyHtmlElement::HtmlCdataSection(node) => node.format().fmt(f),
-            AnyHtmlElement::HtmlComment(node) => node.format().fmt(f),
             AnyHtmlElement::HtmlContent(node) => node.format().fmt(f),
             AnyHtmlElement::HtmlElement(node) => node.format().fmt(f),
             AnyHtmlElement::HtmlSelfClosingElement(node) => node.format().fmt(f),

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

@@ -5,7 +5,6 @@ pub(crate) mod attribute_initializer_clause;
 pub(crate) mod attribute_name;
 pub(crate) mod cdata_section;
 pub(crate) mod closing_element;
-pub(crate) mod comment;
 pub(crate) mod content;
 pub(crate) mod directive;
 pub(crate) mod element;

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

@@ -1,24 +1,26 @@
 use crate::prelude::*;
 use biome_formatter::write;
-use biome_html_syntax::HtmlRoot;
+use biome_html_syntax::{HtmlRoot, HtmlRootFields};
 #[derive(Debug, Clone, Default)]
 pub(crate) struct FormatHtmlRoot;
 impl FormatNodeRule<HtmlRoot> for FormatHtmlRoot {
     fn fmt_fields(&self, node: &HtmlRoot, f: &mut HtmlFormatter) -> FormatResult<()> {
-        if let Some(bom) = node.bom_token() {
-            bom.format().fmt(f)?;
-        }
-        if let Some(directive) = node.directive() {
-            directive.format().fmt(f)?;
-        }
+        let HtmlRootFields {
+            bom_token,
+            directive,
+            html,
+            eof_token,
+        } = node.as_fields();
 
-        node.html().format().fmt(f)?;
-
-        if let Ok(eof) = node.eof_token() {
-            eof.format().fmt(f)?;
-        }
-        write!(f, [hard_line_break()])?;
-
-        Ok(())
+        write!(
+            f,
+            [
+                bom_token.format(),
+                directive.format(),
+                html.format(),
+                hard_line_break(),
+                format_removed(&eof_token?),
+            ]
+        )
     }
 }