feat: swcDtsExtractPlugin

Cargo.toml

@@ -81,6 +81,7 @@ swc_error_reporters = { version = "=1.0.0" }
 swc_html            = { version = "=0.154.0" }
 swc_html_minifier   = { version = "=0.151.0", default-features = false }
 swc_node_comments   = { version = "=0.27.0" }
+swc_typescript      = { version = "=0.8.1" }
 
 rspack_dojang = { version = "0.1.9" }
 [workspace.metadata.release]

crates/rspack_loader_swc/Cargo.toml

@@ -34,5 +34,6 @@ stacker                  = { workspace = true }
 swc_config               = { workspace = true }
 swc_core                 = { workspace = true, features = ["base", "ecma_ast", "common"] }
 swc_plugin_import        = { version = "0.1.5", path = "../swc_plugin_import" }
+swc_typescript           = { workspace = true }
 tokio                    = { workspace = true }
 url                      = "2.5.0"

crates/rspack_loader_swc/src/compiler.rs

@@ -31,6 +31,7 @@ use swc_core::common::{
 };
 use swc_core::common::{BytePos, SourceFile};
 use swc_core::ecma::ast::{EsVersion, Program};
+use swc_core::ecma::codegen::to_code_with_comments;
 use swc_core::ecma::parser::{
   parse_file_as_module, parse_file_as_program, parse_file_as_script, Syntax,
 };
@@ -40,6 +41,7 @@ use swc_core::{
   base::{config::Options, try_with_handler},
   common::Globals,
 };
+use swc_typescript::fast_dts::FastDts;
 use url::Url;
 
 fn minify_file_comments(
@@ -402,6 +404,16 @@ impl SwcCompiler {
     program
   }
 
+  pub fn transform_dts(&self, config: BuiltInput<impl Fold>) -> Result<String, Error> {
+    // let mut checker = FastDts::new();
+    let comments = config.comments.clone().unwrap();
+
+    let module = config.program.clone().expect_module();
+
+    let dts_code = to_code_with_comments(Some(&comments), &module);
+    Ok(dts_code)
+  }
+
   pub fn input_source_map(
     &self,
     input_src_map: &InputSourceMap,

crates/rspack_loader_swc/src/lib.rs

@@ -133,10 +133,31 @@ impl SwcLoader {
     let ast = c.into_js_ast(program);
     let TransformOutput { code, map } = ast::stringify(&ast, codegen_options)?;
 
+    let emit_dts = swc_options
+      .config
+      .jsc
+      .experimental
+      .emit_isolated_dts
+      .into_bool()
+      && swc_options
+        .config
+        .jsc
+        .syntax
+        .is_some_and(|x| x.typescript());
+
+    if emit_dts {
+      let dts_code = c.transform_dts(built).unwrap();
+      loader_context
+        .parse_meta
+        .entry("swc-loader-dts-extract".into())
+        .and_modify(|v| v.push_str(&dts_code));
+    }
+
     let map = map
       .map(|m| SourceMap::from_json(&m))
       .transpose()
       .map_err(|e| error!(e.to_string()))?;
+    loader_context.emit_diagnostic(diagnostic);
     loader_context.finish_with((code, map));
 
     Ok(())