refactor(rome_formatter): Part 4: Move verbatim formatting to rome_formatter

crates/rome_formatter/src/lib.rs

@@ -36,7 +36,7 @@ pub mod prelude;
 pub mod printed_tokens;
 pub mod printer;
 mod source_map;
-pub mod token;
+mod verbatim;
 
 use crate::formatter::Formatter;
 use crate::group_id::UniqueGroupIdBuilder;

crates/rome_formatter/src/verbatim.rs

@@ -0,0 +1,173 @@
+use crate::cst::{FormatLeadingComments, FormatTrailingComments};
+use crate::prelude::*;
+use crate::VecBuffer;
+use crate::{write, CstFormatContext};
+use rome_rowan::{Direction, Language, SyntaxElement, SyntaxNode, TextRange};
+
+/// "Formats" a node according to its original formatting in the source text. Being able to format
+/// a node "as is" is useful if a node contains syntax errors. Formatting a node with syntax errors
+/// has the risk that Rome misinterprets the structure of the code and formatting it could
+/// "mess up" the developers, yet incomplete, work or accidentally introduce new syntax errors.
+///
+/// You may be inclined to call `node.text` directly. However, using `text` doesn't track the nodes
+/// nor its children source mapping information, resulting in incorrect source maps for this subtree.
+///
+/// These nodes and tokens get tracked as [FormatElement::Verbatim], useful to understand
+/// if these nodes still need to have their own implementation.
+pub fn format_verbatim_node<L: Language>(node: &SyntaxNode<L>) -> FormatVerbatimNode<L> {
+    FormatVerbatimNode {
+        node,
+        kind: VerbatimKind::Verbatim {
+            length: node.text_range().len(),
+        },
+        format_comments: true,
+    }
+}
+
+#[derive(Debug, Clone, Copy, Eq, PartialEq)]
+pub struct FormatVerbatimNode<'node, L: Language> {
+    node: &'node SyntaxNode<L>,
+    kind: VerbatimKind,
+    format_comments: bool,
+}
+
+impl<Context> Format<Context> for FormatVerbatimNode<'_, Context::Language>
+where
+    Context: CstFormatContext,
+{
+    fn fmt(&self, f: &mut Formatter<Context>) -> FormatResult<()> {
+        for element in self.node.descendants_with_tokens(Direction::Next) {
+            match element {
+                SyntaxElement::Token(token) => f.state_mut().track_token(&token),
+                SyntaxElement::Node(node) => {
+                    f.context().comments().mark_suppression_checked(&node);
+                }
+            }
+        }
+
+        // The trimmed range of a node is its range without any of its leading or trailing trivia.
+        // Except for nodes that used to be parenthesized, the range than covers the source from the
+        // `(` to the `)` (the trimmed range of the parenthesized expression, not the inner expression)
+        let trimmed_source_range = f.context().source_map().map_or_else(
+            || self.node.text_trimmed_range(),
+            |source_map| source_map.trimmed_source_range(self.node),
+        );
+
+        let mut buffer = VecBuffer::new(f.state_mut());
+
+        write!(
+            buffer,
+            [format_with(|f: &mut Formatter<Context>| {
+                fn source_range<Context>(f: &Formatter<Context>, range: TextRange) -> TextRange
+                where
+                    Context: CstFormatContext,
+                {
+                    f.context()
+                        .source_map()
+                        .map_or_else(|| range, |source_map| source_map.source_range(range))
+                }
+
+                // Format all leading comments that are outside of the node's source range.
+                if self.format_comments {
+                    let comments = f.context().comments().clone();
+                    let leading_comments = comments.leading_comments(self.node);
+
+                    let outside_trimmed_range = leading_comments.partition_point(|comment| {
+                        comment.piece().text_range().end() <= trimmed_source_range.start()
+                    });
+
+                    write!(
+                        f,
+                        [FormatLeadingComments::Comments(
+                            &leading_comments[..outside_trimmed_range]
+                        )]
+                    )?;
+                }
+
+                // Find the first skipped token trivia, if any, and include it in the verbatim range because
+                // the comments only format **up to** but not including skipped token trivia.
+                let start_source = self
+                    .node
+                    .first_leading_trivia()
+                    .into_iter()
+                    .flat_map(|trivia| trivia.pieces())
+                    .filter(|trivia| trivia.is_skipped())
+                    .map(|trivia| source_range(f, trivia.text_range()).start())
+                    .take_while(|start| *start < trimmed_source_range.start())
+                    .next()
+                    .unwrap_or_else(|| trimmed_source_range.start());
+
+                let original_source = f.context().source_map().map_or_else(
+                    || self.node.text_trimmed().to_string(),
+                    |source_map| {
+                        source_map.text()[trimmed_source_range.cover_offset(start_source)]
+                            .to_string()
+                    },
+                );
+
+                dynamic_text(
+                    &normalize_newlines(&original_source, LINE_TERMINATORS),
+                    self.node.text_trimmed_range().start(),
+                )
+                .fmt(f)?;
+
+                // Format all trailing comments that are outside of the trimmed range.
+                if self.format_comments {
+                    let comments = f.context().comments().clone();
+
+                    let trailing_comments = comments.trailing_comments(self.node);
+
+                    let outside_trimmed_range_start =
+                        trailing_comments.partition_point(|comment| {
+                            source_range(f, comment.piece().text_range()).end()
+                                <= trimmed_source_range.end()
+                        });
+
+                    write!(
+                        f,
+                        [FormatTrailingComments::Comments(
+                            &trailing_comments[outside_trimmed_range_start..]
+                        )]
+                    )?;
+                }
+
+                Ok(())
+            })]
+        )?;
+
+        let content = buffer.into_vec();
+
+        let verbatim = Verbatim {
+            content: content.into_boxed_slice(),
+            kind: self.kind,
+        };
+
+        f.write_element(FormatElement::Verbatim(verbatim))
+    }
+}
+
+impl<L: Language> FormatVerbatimNode<'_, L> {
+    pub fn skip_comments(mut self) -> Self {
+        self.format_comments = false;
+        self
+    }
+}
+
+/// Formats unknown nodes. The difference between this method  and `format_verbatim` is that this method
+/// doesn't track nodes/tokens as [FormatElement::Verbatim]. They are just printed as they are.
+pub fn format_unknown_node<L: Language>(node: &SyntaxNode<L>) -> FormatVerbatimNode<L> {
+    FormatVerbatimNode {
+        node,
+        kind: VerbatimKind::Unknown,
+        format_comments: true,
+    }
+}
+
+/// Format a node having formatter suppression comment applied to it
+pub fn format_suppressed_node<L: Language>(node: &SyntaxNode<L>) -> FormatVerbatimNode<L> {
+    FormatVerbatimNode {
+        node,
+        kind: VerbatimKind::Suppressed,
+        format_comments: true,
+    }
+}