feat(transformer): add transform-typescript boilerplate (#2866)

Cargo.lock

@@ -1752,6 +1752,8 @@ dependencies = [
  "oxc_tasks_common",
  "oxc_transformer",
  "pico-args",
+ "serde",
+ "serde_json",
  "walkdir",
 ]
 
@@ -1766,6 +1768,7 @@ dependencies = [
  "oxc_parser",
  "oxc_semantic",
  "oxc_span",
+ "serde",
 ]
 
 [[package]]

crates/oxc_transformer/Cargo.toml

@@ -25,6 +25,8 @@ oxc_allocator   = { workspace = true }
 oxc_semantic    = { workspace = true }
 oxc_diagnostics = { workspace = true }
 
+serde = { workspace = true }
+
 [dev-dependencies]
 oxc_parser  = { workspace = true }
 oxc_codegen = { workspace = true }

crates/oxc_transformer/examples/transformer.rs

@@ -42,7 +42,7 @@ fn main() {
         .semantic;
 
     let program = allocator.alloc(ret.program);
-    let transform_options = TransformOptions {};
+    let transform_options = TransformOptions::default();
     Transformer::new(&allocator, source_type, semantic, transform_options).build(program).unwrap();
 
     let printed = Codegen::<false>::new("", &source_text, CodegenOptions::default())

crates/oxc_transformer/src/lib.rs

@@ -5,7 +5,8 @@
 //! * <https://babel.dev/docs/presets>
 //! * <https://github.com/microsoft/TypeScript/blob/main/src/compiler/transformer.ts>
 
-mod options;
+// Plugins: <https://babeljs.io/docs/plugins-list>
+mod typescript;
 
 use oxc_allocator::Allocator;
 use oxc_ast::ast::Program;
@@ -13,7 +14,13 @@ use oxc_diagnostics::Error;
 use oxc_semantic::Semantic;
 use oxc_span::SourceType;
 
-pub use crate::options::TransformOptions;
+pub use crate::typescript::{TypeScript, TypeScriptOptions};
+
+#[derive(Debug, Default, Clone)]
+pub struct TransformOptions {
+    #[allow(unused)]
+    pub typescript: TypeScriptOptions,
+}
 
 #[allow(unused)]
 pub struct Transformer<'a> {
@@ -21,6 +28,8 @@ pub struct Transformer<'a> {
     source_type: SourceType,
     semantic: Semantic<'a>,
     options: TransformOptions,
+
+    typescript: TypeScript,
 }
 
 impl<'a> Transformer<'a> {
@@ -30,7 +39,7 @@ impl<'a> Transformer<'a> {
         semantic: Semantic<'a>,
         options: TransformOptions,
     ) -> Self {
-        Self { allocator, source_type, semantic, options }
+        Self { allocator, source_type, semantic, options, typescript: TypeScript::default() }
     }
 
     /// # Errors

crates/oxc_transformer/src/options.rs

@@ -1,3 +0,0 @@
-#[allow(clippy::empty_structs_with_brackets)]
-#[derive(Debug, Default, Clone)]
-pub struct TransformOptions {}

crates/oxc_transformer/src/typescript/mod.rs

@@ -0,0 +1,34 @@
+//! <https://babeljs.io/docs/babel-plugin-transform-typescript>
+
+use serde::Deserialize;
+
+#[derive(Debug, Default, Clone, Deserialize)]
+#[serde(rename_all = "camelCase")]
+pub struct TypeScriptOptions;
+
+/// This plugin adds support for the types syntax used by the TypeScript programming language.
+/// However, this plugin does not add the ability to type-check the JavaScript passed to it.
+/// For that, you will need to install and set up TypeScript.
+///
+/// Note that although the TypeScript compiler tsc actively supports certain JavaScript proposals such as optional chaining (?.),
+/// nullish coalescing (??) and class properties (this.#x), this preset does not include these features
+/// because they are not the types syntax available in TypeScript only.
+/// We recommend using preset-env with preset-typescript if you want to transpile these features.
+///
+/// This plugin is included in `preset-typescript`.
+///
+/// ## Example
+///
+/// In:  `const x: number = 0;`
+/// Out: `const x = 0;`
+#[derive(Debug, Default)]
+pub struct TypeScript {
+    #[allow(unused)]
+    options: TypeScriptOptions,
+}
+
+impl TypeScript {
+    pub fn new(options: TypeScriptOptions) -> Self {
+        Self { options }
+    }
+}

crates/oxc_wasm/src/lib.rs

@@ -232,7 +232,7 @@ impl Oxc {
                 .build_module_record(PathBuf::new(), program)
                 .build(program)
                 .semantic;
-            let options = TransformOptions {};
+            let options = TransformOptions::default();
             let result =
                 Transformer::new(&allocator, source_type, semantic, options).build(program);
             if let Err(errs) = result {

tasks/transform_conformance/Cargo.toml

@@ -29,6 +29,9 @@ oxc_codegen      = { workspace = true }
 oxc_transformer  = { workspace = true }
 oxc_tasks_common = { workspace = true }
 oxc_diagnostics  = { workspace = true }
+
 walkdir    = { workspace = true }
 pico-args  = { workspace = true }
 indexmap   = { workspace = true }
+serde      = { workspace = true }
+serde_json = { workspace = true }

tasks/transform_conformance/src/test_case.rs

@@ -10,9 +10,9 @@ use oxc_parser::Parser;
 use oxc_semantic::SemanticBuilder;
 use oxc_span::{SourceType, VALID_EXTENSIONS};
 use oxc_tasks_common::{normalize_path, print_diff_in_terminal, BabelOptions};
-use oxc_transformer::{TransformOptions, Transformer};
-// use serde::de::DeserializeOwned;
-// use serde_json::Value;
+use oxc_transformer::{TransformOptions, Transformer, TypeScriptOptions};
+use serde::de::DeserializeOwned;
+use serde_json::Value;
 
 use crate::{fixture_root, root, TestRunnerEnv};
 
@@ -78,12 +78,16 @@ pub trait TestCase {
     fn path(&self) -> &Path;
 
     fn transform_options(&self) -> TransformOptions {
-        // fn get_options<T: Default + DeserializeOwned>(value: Option<Value>) -> T {
-        // value.and_then(|v| serde_json::from_value::<T>(v).ok()).unwrap_or_default()
-        // }
-
-        // let options = self.options();
-        TransformOptions {}
+        fn get_options<T: Default + DeserializeOwned>(value: Option<Value>) -> T {
+            value.and_then(|v| serde_json::from_value::<T>(v).ok()).unwrap_or_default()
+        }
+        let options = self.options();
+        TransformOptions {
+            typescript: options
+                .get_plugin("transform-typescript")
+                .map(get_options::<TypeScriptOptions>)
+                .unwrap_or_default(),
+        }
     }
 
     fn skip_test_case(&self) -> bool {