refactor(formatter): Split oxc_formatter and oxc_formatter_core (#22611)

Split `oxc_formatter` into:

- `oxc_formatter(_js)`: JS/TS specific formatter, comment handling, sortImports, jsdoc, etc
- `oxc_formatter_core`: Language agnostic IR, printer, etc

The naming convention is different from Biome or Ruff (they do not have `_core`, and `_formatter` is equivalent to the core), but this is because in Oxc, items without `_js` are the default.

As a basic task, I have added `Context` as a generic to all relevant parts to ensure support for multiple languages.

There might still be other components that could be refactored into the core, but I would like to finish them as I implement support for other languages.

Also moved some shared utilities to the core in advance.

Author: leaysgur

Cargo.lock

@@ -143,6 +143,7 @@ oxc_traverse = { version = "0.133.0", path = "crates/oxc_traverse" } # AST trave
 
 # publish = false
 oxc_formatter = { path = "crates/oxc_formatter" } # Code formatting
+oxc_formatter_core = { path = "crates/oxc_formatter_core" } # Language-agnostic formatter core
 oxc_language_server = { path = "crates/oxc_language_server", default-features = false } # Language server
 oxc_linter = { path = "crates/oxc_linter" } # Linting engine
 oxc_macros = { path = "crates/oxc_macros" } # Proc macros

Cargo.toml

@@ -33,6 +33,7 @@ oxc_config = { workspace = true }
 oxc_data_structures = { workspace = true, features = ["rope"] }
 oxc_diagnostics = { workspace = true }
 oxc_formatter = { workspace = true }
+oxc_formatter_core = { workspace = true }
 oxc_language_server = { workspace = true }
 oxc_napi = { workspace = true }
 oxc_parser = { workspace = true }

apps/oxfmt/Cargo.toml

@@ -7,7 +7,7 @@ use tracing::{debug, instrument};
 use oxc_allocator::Allocator;
 use oxc_ast::ast::*;
 use oxc_formatter::{
-    AstNode, AstNodes, FormatOptions, FormatVueBindingParams, FormatVueScriptGeneric, Formatter,
+    AstNode, AstNodes, FormatVueBindingParams, FormatVueScriptGeneric, Formatter, JsFormatOptions,
     enable_jsx_source_type, get_parse_options,
 };
 use oxc_parser::{Parser, ParserReturn};
@@ -197,7 +197,7 @@ fn run_fragment(
 
     let formatter = Formatter::new(
         &allocator,
-        FormatOptions {
+        JsFormatOptions {
             // TODO: Fragments inside of Vue attributes should always use single quotes,
             // since double quotes are used for the attribute value itself.
             //

apps/oxfmt/src/api/text_to_doc_api.rs

@@ -21,7 +21,7 @@ use tracing::instrument;
 
 use oxc_config::{ConfigDiscovery, ConfigFileNames, DiscoveredConfigFile, is_js_config_path};
 #[cfg(feature = "napi")]
-use oxc_formatter::FormatOptions;
+use oxc_formatter::JsFormatOptions;
 
 use self::{
     editorconfig::{apply_editorconfig, has_editorconfig_overrides, load_editorconfig},
@@ -151,7 +151,7 @@ pub fn resolve_for_api(
 #[cfg(feature = "napi")]
 #[derive(Debug)]
 pub struct EmbeddedCallbackResolved {
-    pub format_options: Box<FormatOptions>,
+    pub format_options: Box<JsFormatOptions>,
     /// Retained so nested embedded callbacks can derive Prettier options on demand.
     /// (e.g., CSS-in-JS inside the embedded JS)
     pub config: Box<FormatConfig>,

apps/oxfmt/src/core/config/mod.rs

@@ -10,7 +10,7 @@ use serde_json::Value;
 use tracing::{debug, debug_span};
 
 use oxc_formatter::{
-    EmbeddedDocFormatterCallback, EmbeddedFormatterCallback, ExternalCallbacks, FormatOptions,
+    EmbeddedDocFormatterCallback, EmbeddedFormatterCallback, ExternalCallbacks, JsFormatOptions,
     TailwindCallback,
 };
 
@@ -241,7 +241,7 @@ impl ExternalFormatter {
     /// The options (including `filepath`) are captured in the closures and passed to JS on each call.
     pub fn to_external_callbacks(
         &self,
-        format_options: &FormatOptions,
+        format_options: &JsFormatOptions,
         options: Value,
     ) -> ExternalCallbacks {
         let needs_embedded = !format_options.embedded_language_formatting.is_off();

apps/oxfmt/src/core/external_formatter.rs

@@ -6,7 +6,7 @@ use tracing::instrument;
 
 use oxc_allocator::AllocatorPool;
 use oxc_diagnostics::OxcDiagnostic;
-use oxc_formatter::{FormatOptions, Formatter, enable_jsx_source_type, get_parse_options};
+use oxc_formatter::{Formatter, JsFormatOptions, enable_jsx_source_type, get_parse_options};
 use oxc_parser::Parser;
 use oxc_span::SourceType;
 use oxc_toml::Options as TomlFormatterOptions;
@@ -37,7 +37,7 @@ pub enum FormatStrategy {
     OxcFormatter {
         path: Arc<Path>,
         source_type: SourceType,
-        format_options: Box<FormatOptions>,
+        format_options: Box<JsFormatOptions>,
         #[cfg(feature = "napi")]
         config: Box<FormatConfig>,
         insert_final_newline: bool,
@@ -92,7 +92,7 @@ impl FormatStrategy {
     /// and `Box<FormatConfig>` is materially smaller per file than a fully-built `Value`.
     ///
     /// # Errors
-    /// Returns `Err` if the kind needs `FormatOptions`/`TomlFormatterOptions`
+    /// Returns `Err` if the kind needs `JsFormatOptions`/`TomlFormatterOptions`
     /// and the config fails validation.
     // `config` is moved into the napi-only `ExternalFormatter*` variants;
     // when the `napi` feature is off, those branches are cfg-gated out and the
@@ -268,7 +268,7 @@ impl SourceFormatter {
         source_text: &str,
         path: &Path,
         source_type: SourceType,
-        format_options: FormatOptions,
+        format_options: JsFormatOptions,
         #[cfg(feature = "napi")] config: &FormatConfig,
     ) -> Result<String, OxcDiagnostic> {
         let source_type = enable_jsx_source_type(source_type);
@@ -344,7 +344,7 @@ impl SourceFormatter {
     /// to fire based on user config.
     fn build_external_callbacks(
         &self,
-        format_options: &FormatOptions,
+        format_options: &JsFormatOptions,
         config: &FormatConfig,
         path: &Path,
     ) -> oxc_formatter::ExternalCallbacks {

apps/oxfmt/src/core/format.rs

@@ -1,7 +1,7 @@
 //! Converters from typed [`super::oxfmtrc::FormatConfig`] to each downstream
 //! consumer's options shape.
 //!
-//! - [`to_oxc_formatter()`]: `oxc_formatter::FormatOptions` for JS/TS formatting
+//! - [`to_oxc_formatter()`]: `oxc_formatter::JsFormatOptions` for JS/TS formatting
 //! - [`to_toml_formatter()`]: `oxc_toml::Options` for TOML formatting
 //! - `to_prettier`: Prettier-compatible JSON, plus `inject_*` helpers for
 //!   layering in `parser` / `filepath` / plugin payloads at the format step

apps/oxfmt/src/core/options/mod.rs

@@ -2,10 +2,11 @@ use rustc_hash::FxHashSet;
 
 use oxc_formatter::{
     ArrowParentheses, AttributePosition, BracketSameLine, BracketSpacing, CustomGroupDefinition,
-    EmbeddedLanguageFormatting, Expand, FormatOptions, GroupEntry, ImportModifier, ImportSelector,
-    IndentStyle, IndentWidth, LineEnding, LineWidth, QuoteProperties, QuoteStyle, Semicolons,
-    SortImportsOptions, SortOrder, SortTailwindcssOptions, TrailingCommas,
+    EmbeddedLanguageFormatting, Expand, GroupEntry, ImportModifier, ImportSelector,
+    JsFormatOptions, QuoteProperties, QuoteStyle, Semicolons, SortImportsOptions, SortOrder,
+    SortTailwindcssOptions, TrailingCommas,
 };
+use oxc_formatter_core::{IndentStyle, IndentWidth, LineEnding, LineWidth};
 
 use super::super::oxfmtrc::{
     ArrowParensConfig, CustomGroupItemConfig, EmbeddedLanguageFormattingConfig, EndOfLineConfig,
@@ -14,18 +15,18 @@ use super::super::oxfmtrc::{
     SortTailwindcssUserConfig, TrailingCommaConfig,
 };
 
-/// Convert `FormatConfig` into validated `FormatOptions` for `oxc_formatter`.
+/// Convert `FormatConfig` into validated `JsFormatOptions` for `oxc_formatter`.
 ///
 /// # Errors
 /// Returns error if any option value is invalid
-pub fn to_oxc_formatter(config: &FormatConfig) -> Result<FormatOptions, String> {
+pub fn to_oxc_formatter(config: &FormatConfig) -> Result<JsFormatOptions, String> {
     // NOTE: Not yet supported options:
     // [Prettier] experimentalOperatorPosition: "start" | "end"
     // [Prettier] experimentalTernaries: boolean
     // These are rejected at deserialize time so they never reach here.
 
-    // All values are based on defaults from `FormatOptions::default()`
-    let mut format_options = FormatOptions::default();
+    // All values are based on defaults from `JsFormatOptions::default()`
+    let mut format_options = JsFormatOptions::default();
 
     // [Prettier] useTabs: boolean
     if let Some(use_tabs) = config.use_tabs {

apps/oxfmt/src/core/options/to_oxc_formatter.rs

@@ -4,7 +4,7 @@ use std::path::Path;
 use serde::Serialize;
 use serde_json::Value;
 
-use oxc_formatter::FormatOptions;
+use oxc_formatter::JsFormatOptions;
 
 use super::super::oxfmtrc::{
     ArrowParensConfig, EmbeddedLanguageFormattingConfig, EndOfLineConfig, FormatConfig,
@@ -31,7 +31,7 @@ pub fn to_prettier(config: &FormatConfig) -> Value {
     // / `ResolvedFormatConfig`) instead of the JS formatter's typed enum once available.
     obj.insert(
         "printWidth".to_string(),
-        Value::from(config.print_width.unwrap_or(FormatOptions::default().line_width.value())),
+        Value::from(config.print_width.unwrap_or(JsFormatOptions::default().line_width.value())),
     );
 
     // Other Prettier core options share defaults with oxfmt,