feat(grit): add range formatting (#4525)

Co-authored-by: Arend van Beelen jr. <[email protected]>

crates/biome_grit_formatter/src/lib.rs

@@ -10,14 +10,14 @@ use biome_formatter::{
     comments::Comments,
     prelude::*,
     trivia::{format_dangling_comments, format_leading_comments, format_trailing_comments},
-    write, CstFormatContext, Format, FormatLanguage, FormatResult, Formatted,
+    write, CstFormatContext, Format, FormatLanguage, FormatResult, Formatted, Printed,
 };
 use biome_grit_syntax::{GritLanguage, GritSyntaxNode};
 use comments::GritCommentStyle;
 
 pub(crate) use crate::context::GritFormatContext;
 
-use biome_rowan::AstNode;
+use biome_rowan::{AstNode, TextRange};
 use context::GritFormatOptions;
 use cst::FormatGritSyntaxNode;
 
@@ -33,6 +33,39 @@ pub fn format_node(
     biome_formatter::format_node(root, GritFormatLanguage::new(options))
 }
 
+/// Formats a range within a file, supported by Biome
+///
+/// This runs a simple heuristic to determine the initial indentation
+/// level of the node based on the provided [GritFormatOptions], which
+/// must match the current indentation of the file. Additionally,
+/// because the reformatting happens only locally the resulting code
+/// will be indented with the same level as the original selection,
+/// even if it's a mismatch from the rest of the block the selection is in
+///
+/// It returns a [Printed] result with a range corresponding to the
+/// range of the input that was effectively overwritten by the formatter
+pub fn format_range(
+    options: GritFormatOptions,
+    root: &GritSyntaxNode,
+    range: TextRange,
+) -> FormatResult<Printed> {
+    biome_formatter::format_range(root, range, GritFormatLanguage::new(options))
+}
+
+/// Formats a single node within a file, supported by Biome.
+///
+/// This runs a simple heuristic to determine the initial indentation
+/// level of the node based on the provided [GritFormatOptions], which
+/// must match the current indentation of the file. Additionally,
+/// because the reformatting happens only locally the resulting code
+/// will be indented with the same level as the original selection,
+/// even if it's a mismatch from the rest of the block the selection is in
+///
+/// Returns the [Printed] code.
+pub fn format_sub_tree(options: GritFormatOptions, root: &GritSyntaxNode) -> FormatResult<Printed> {
+    biome_formatter::format_sub_tree(root, GritFormatLanguage::new(options))
+}
+
 pub(crate) trait FormatNodeRule<N>
 where
     N: AstNode<Language = GritLanguage>,

crates/biome_service/src/file_handlers/grit.rs

@@ -10,13 +10,13 @@ use crate::{
 };
 use biome_analyze::{AnalyzerConfiguration, AnalyzerOptions};
 use biome_diagnostics::{Diagnostic, Severity};
-use biome_formatter::{IndentStyle, IndentWidth, LineEnding, LineWidth, Printed};
+use biome_formatter::{FormatError, IndentStyle, IndentWidth, LineEnding, LineWidth, Printed};
 use biome_fs::BiomePath;
-use biome_grit_formatter::{context::GritFormatOptions, format_node};
+use biome_grit_formatter::{context::GritFormatOptions, format_node, format_sub_tree};
 use biome_grit_parser::parse_grit_with_cache;
 use biome_grit_syntax::{GritLanguage, GritRoot, GritSyntaxNode};
 use biome_parser::AnyParse;
-use biome_rowan::NodeCache;
+use biome_rowan::{NodeCache, TextRange, TextSize, TokenAtOffset};
 use tracing::debug_span;
 
 #[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
@@ -129,8 +129,8 @@ impl ExtensionHandler for GritFileHandler {
             },
             formatter: FormatterCapabilities {
                 format: Some(format),
-                format_range: None,
-                format_on_type: None,
+                format_range: Some(format_range),
+                format_on_type: Some(format_on_type),
             },
             search: SearchCapabilities { search: None },
         }
@@ -196,6 +196,59 @@ fn format(
     }
 }
 
+#[tracing::instrument(level = "debug", skip_all)]
+fn format_range(
+    biome_path: &BiomePath,
+    document_file_source: &DocumentFileSource,
+    parse: AnyParse,
+    settings: WorkspaceSettingsHandle,
+    range: TextRange,
+) -> Result<Printed, WorkspaceError> {
+    let options = settings.format_options::<GritLanguage>(biome_path, document_file_source);
+
+    let tree = parse.syntax();
+    let printed = biome_grit_formatter::format_range(options, &tree, range)?;
+    Ok(printed)
+}
+
+#[tracing::instrument(level = "debug", skip_all)]
+fn format_on_type(
+    biome_path: &BiomePath,
+    document_file_source: &DocumentFileSource,
+    parse: AnyParse,
+    settings: WorkspaceSettingsHandle,
+    offset: TextSize,
+) -> Result<Printed, WorkspaceError> {
+    let options = settings.format_options::<GritLanguage>(biome_path, document_file_source);
+
+    let tree = parse.syntax();
+
+    let range = tree.text_range();
+    if offset < range.start() || offset > range.end() {
+        return Err(WorkspaceError::FormatError(FormatError::RangeError {
+            input: TextRange::at(offset, TextSize::from(0)),
+            tree: range,
+        }));
+    }
+
+    let token = match tree.token_at_offset(offset) {
+        // File is empty, do nothing
+        TokenAtOffset::None => panic!("empty file"),
+        TokenAtOffset::Single(token) => token,
+        // The cursor should be right after the closing character that was just typed,
+        // select the previous token as the correct one
+        TokenAtOffset::Between(token, _) => token,
+    };
+
+    let root_node = match token.parent() {
+        Some(node) => node,
+        None => panic!("found a token with no parent"),
+    };
+
+    let printed = format_sub_tree(options, &root_node)?;
+    Ok(printed)
+}
+
 #[tracing::instrument(level = "debug", skip(params))]
 fn lint(params: LintParams) -> LintResults {
     let _ = debug_span!("Linting Grit file", path =? params.path, language =? params.language)