fix(napi/transform): fix 'typescript.declaration' option not working (#7012)

fixes #7010

crates/oxc/src/napi/isolated_declarations.rs

@@ -22,3 +22,9 @@ pub struct IsolatedDeclarationsOptions {
 
     pub sourcemap: Option<bool>,
 }
+
+impl From<IsolatedDeclarationsOptions> for oxc_isolated_declarations::IsolatedDeclarationsOptions {
+    fn from(options: IsolatedDeclarationsOptions) -> Self {
+        Self { strip_internal: options.strip_internal.unwrap_or_default() }
+    }
+}

napi/transform/src/transformer.rs

@@ -6,6 +6,7 @@ use napi_derive::napi;
 use oxc::{
     codegen::CodegenReturn,
     diagnostics::OxcDiagnostic,
+    isolated_declarations::IsolatedDeclarationsOptions,
     napi::{
         source_map::SourceMap,
         transform::{TransformOptions, TransformResult},
@@ -20,6 +21,8 @@ use crate::errors::wrap_diagnostics;
 #[derive(Default)]
 struct Compiler {
     transform_options: oxc::transformer::TransformOptions,
+    isolated_declaration_options: Option<oxc::isolated_declarations::IsolatedDeclarationsOptions>,
+
     sourcemap: bool,
 
     printed: String,
@@ -37,6 +40,13 @@ struct Compiler {
 impl Compiler {
     fn new(options: Option<TransformOptions>) -> Result<Self, Vec<OxcDiagnostic>> {
         let mut options = options;
+
+        let isolated_declaration_options = options
+            .as_ref()
+            .and_then(|o| o.typescript.as_ref())
+            .and_then(|o| o.declaration)
+            .map(oxc::isolated_declarations::IsolatedDeclarationsOptions::from);
+
         let sourcemap = options.as_ref().and_then(|o| o.sourcemap).unwrap_or_default();
 
         let define = options
@@ -76,8 +86,10 @@ impl Compiler {
 
         let transform_options =
             options.map(oxc::transformer::TransformOptions::from).unwrap_or_default();
+
         Ok(Self {
             transform_options,
+            isolated_declaration_options,
             sourcemap,
             printed: String::default(),
             printed_sourcemap: None,
@@ -103,6 +115,10 @@ impl CompilerInterface for Compiler {
         Some(self.transform_options.clone())
     }
 
+    fn isolated_declaration_options(&self) -> Option<IsolatedDeclarationsOptions> {
+        self.isolated_declaration_options
+    }
+
     fn define_options(&self) -> Option<ReplaceGlobalDefinesConfig> {
         self.define.clone()
     }
@@ -173,6 +189,7 @@ pub fn transform(
             }
         }
     };
+
     compiler.compile(&source_text, source_type, source_path);
 
     TransformResult {

napi/transform/test/transform.test.mjs

@@ -3,26 +3,31 @@ import { assert, describe, it } from 'vitest';
 import oxc from './index.js';
 
 describe('transform', () => {
-  const code = 'class A<T> {}';
+  const code = 'export class A<T> {}';
 
   it('matches output', () => {
     const ret = oxc.transform('test.ts', code, { sourcemap: true });
     assert.deepEqual(ret, {
-      code: 'class A {}\n',
+      code: 'export class A {}\n',
       errors: [],
       map: {
-        mappings: 'AAAA,MAAM,EAAK,CAAE',
+        mappings: 'AAAA,OAAO,MAAM,EAAK,CAAE',
         names: [],
         sources: ['test.ts'],
-        sourcesContent: ['class A<T> {}'],
+        sourcesContent: ['export class A<T> {}'],
         version: 3,
       },
     });
   });
 
-  it('lang', () => {
+  it('uses the `lang` option', () => {
     const ret = oxc.transform('test.vue', code, { lang: 'ts' });
-    assert.equal(ret.code, 'class A {}\n');
+    assert.equal(ret.code, 'export class A {}\n');
+  });
+
+  it('uses the `declaration option`', () => {
+    const ret = oxc.transform('test.ts', code, { typescript: { declaration: true } });
+    assert.equal(ret.declaration, 'export declare class A<T> {}\n');
   });
 });
 
@@ -35,7 +40,6 @@ describe('react refresh plugin', () => {
 
   it('matches output', () => {
     const ret = oxc.transform('test.tsx', code, { jsx: { refresh: {} } });
-    console.log(ret.code);
     assert.equal(
       ret.code,
       `import { useState } from "react";