feat(napi/parser): add get_line_column_number API

napi/parser/Cargo.toml

@@ -23,6 +23,7 @@ doctest = false
 [dependencies]
 oxc = { workspace = true }
 oxc_ast = { workspace = true, features = ["serialize"] } # enable feature only
+oxc_data_structures = { workspace = true }
 oxc_napi = { workspace = true }
 
 rustc-hash = { workspace = true }

napi/parser/index.d.ts

@@ -3,7 +3,10 @@
 
 export * from '@oxc-project/types';
 export declare class MagicString {
+  /** Get source text from utf8 offset. */
   getSourceText(start: number, end: number): string
+  /** Get 0-based line and column number from utf8 offset. */
+  getLineColumnNumber(offset: number): LineColumn
   length(): number
   toString(): string
   append(input: string): this
@@ -131,6 +134,11 @@ export declare const enum ImportNameKind {
   Default = 'Default'
 }
 
+export interface LineColumn {
+  line: number
+  column: number
+}
+
 export interface OverwriteOptions {
   contentOnly: boolean
 }

napi/parser/src/magic_string.rs

@@ -2,6 +2,7 @@
 // use std::sync::Arc;
 
 use napi_derive::napi;
+use oxc_data_structures::rope::{get_line_column, Rope};
 
 // use oxc_sourcemap::napi::SourceMap;
 use self_cell::self_cell;
@@ -10,6 +11,7 @@ use string_wizard::MagicString as MS;
 #[napi]
 pub struct MagicString {
     cell: MagicStringImpl,
+    rope: Option<Rope>,
 }
 
 self_cell!(
@@ -22,10 +24,19 @@ self_cell!(
 
 impl MagicString {
     pub fn new(source_text: String) -> Self {
-        Self { cell: MagicStringImpl::new(source_text, |s| string_wizard::MagicString::new(s)) }
+        Self {
+            cell: MagicStringImpl::new(source_text, |s| string_wizard::MagicString::new(s)),
+            rope: None,
+        }
     }
 }
 
+#[napi(object)]
+pub struct LineColumn {
+    pub line: u32,
+    pub column: u32,
+}
+
 #[napi(object)]
 pub struct OverwriteOptions {
     pub content_only: bool,
@@ -40,11 +51,21 @@ pub struct SourceMapOptions {
 
 #[napi]
 impl MagicString {
+    /// Get source text from utf8 offset.
     #[napi]
     pub fn get_source_text(&self, start: u32, end: u32) -> &str {
         &self.cell.borrow_owner()[start as usize..end as usize]
     }
 
+    /// Get 0-based line and column number from utf8 offset.
+    #[napi]
+    pub fn get_line_column_number(&mut self, offset: u32) -> LineColumn {
+        let source_text = self.cell.borrow_owner();
+        let rope = self.rope.get_or_insert_with(|| Rope::from_str(source_text));
+        let (line, column) = get_line_column(rope, offset, source_text);
+        LineColumn { line, column }
+    }
+
     #[napi]
     pub fn length(&self) -> u32 {
         self.cell.borrow_dependent().len() as u32

napi/parser/test/magic_string.test.ts

@@ -19,6 +19,12 @@ describe('simple', () => {
     // Access source text by utf8 offset.
     expect(ms.getSourceText(start, end)).toEqual('测试');
 
+    // Access line and column number from utf8 offset.
+    expect(ms.getLineColumnNumber(start)).toStrictEqual({
+      line: 0,
+      column: 19,
+    });
+
     // Magic string manipulation.
     ms.remove(start, end).append(';');
     expect(ms.toString()).toEqual('const s: String = "";');