feat(transformer/typescript): support rewrite_import_extensions option (#5399)

close: #5395

Babel only supports `rewrite`, we also support `remove`

crates/oxc_transformer/src/lib.rs

@@ -48,7 +48,7 @@ pub use crate::{
     es2015::{ArrowFunctionsOptions, ES2015Options},
     options::{BabelOptions, TransformOptions},
     react::{ReactJsxRuntime, ReactOptions, ReactRefreshOptions},
-    typescript::TypeScriptOptions,
+    typescript::{RewriteExtensionsMode, TypeScriptOptions},
 };
 use crate::{
     context::{Ctx, TransformCtx},
@@ -383,6 +383,30 @@ impl<'a> Traverse<'a> for Transformer<'a> {
         self.x3_es2015.enter_variable_declarator(node, ctx);
     }
 
+    fn enter_import_declaration(
+        &mut self,
+        node: &mut ImportDeclaration<'a>,
+        ctx: &mut TraverseCtx<'a>,
+    ) {
+        self.x0_typescript.enter_import_declaration(node, ctx);
+    }
+
+    fn enter_export_all_declaration(
+        &mut self,
+        node: &mut ExportAllDeclaration<'a>,
+        ctx: &mut TraverseCtx<'a>,
+    ) {
+        self.x0_typescript.enter_export_all_declaration(node, ctx);
+    }
+
+    fn enter_export_named_declaration(
+        &mut self,
+        node: &mut ExportNamedDeclaration<'a>,
+        ctx: &mut TraverseCtx<'a>,
+    ) {
+        self.x0_typescript.enter_export_named_declaration(node, ctx);
+    }
+
     fn enter_ts_export_assignment(
         &mut self,
         export_assignment: &mut TSExportAssignment<'a>,

crates/oxc_transformer/src/options/transformer.rs

@@ -196,12 +196,23 @@ impl TransformOptions {
         });
 
         transformer_options.typescript = {
-            let plugin_name = "transform-typescript";
-            from_value::<TypeScriptOptions>(get_plugin_options(plugin_name, options))
+            let preset_name = "typescript";
+            if options.has_preset("typescript") {
+                from_value::<TypeScriptOptions>(
+                    get_preset_options("typescript", options).unwrap_or_else(|| json!({})),
+                )
                 .unwrap_or_else(|err| {
-                    report_error(plugin_name, &err, false, &mut errors);
+                    report_error(preset_name, &err, true, &mut errors);
                     TypeScriptOptions::default()
                 })
+            } else {
+                let plugin_name = "transform-typescript";
+                from_value::<TypeScriptOptions>(get_plugin_options(plugin_name, options))
+                    .unwrap_or_else(|err| {
+                        report_error(plugin_name, &err, false, &mut errors);
+                        TypeScriptOptions::default()
+                    })
+            }
         };
 
         transformer_options.assumptions = if options.assumptions.is_null() {

crates/oxc_transformer/src/typescript/mod.rs

@@ -4,14 +4,16 @@ mod r#enum;
 mod module;
 mod namespace;
 mod options;
+mod rewrite_extensions;
 
 use std::rc::Rc;
 
 use oxc_allocator::Vec;
 use oxc_ast::ast::*;
-use oxc_traverse::TraverseCtx;
+use oxc_traverse::{Traverse, TraverseCtx};
+use rewrite_extensions::TypeScriptRewriteExtensions;
 
-pub use self::options::TypeScriptOptions;
+pub use self::options::{RewriteExtensionsMode, TypeScriptOptions};
 use self::{annotations::TypeScriptAnnotations, r#enum::TypeScriptEnum};
 use crate::context::Ctx;
 
@@ -43,6 +45,7 @@ pub struct TypeScript<'a> {
 
     annotations: TypeScriptAnnotations<'a>,
     r#enum: TypeScriptEnum<'a>,
+    rewrite_extensions: TypeScriptRewriteExtensions,
 }
 
 impl<'a> TypeScript<'a> {
@@ -52,12 +55,47 @@ impl<'a> TypeScript<'a> {
         Self {
             annotations: TypeScriptAnnotations::new(Rc::clone(&options), Rc::clone(&ctx)),
             r#enum: TypeScriptEnum::new(Rc::clone(&ctx)),
+            rewrite_extensions: TypeScriptRewriteExtensions::new(
+                options.rewrite_import_extensions.clone().unwrap_or_default(),
+            ),
             options,
             ctx,
         }
     }
 }
 
+impl<'a> Traverse<'a> for TypeScript<'a> {
+    fn enter_import_declaration(
+        &mut self,
+        node: &mut ImportDeclaration<'a>,
+        ctx: &mut TraverseCtx<'a>,
+    ) {
+        if self.options.rewrite_import_extensions.is_some() {
+            self.rewrite_extensions.enter_import_declaration(node, ctx);
+        }
+    }
+
+    fn enter_export_all_declaration(
+        &mut self,
+        node: &mut ExportAllDeclaration<'a>,
+        ctx: &mut TraverseCtx<'a>,
+    ) {
+        if self.options.rewrite_import_extensions.is_some() {
+            self.rewrite_extensions.enter_export_all_declaration(node, ctx);
+        }
+    }
+
+    fn enter_export_named_declaration(
+        &mut self,
+        node: &mut ExportNamedDeclaration<'a>,
+        ctx: &mut TraverseCtx<'a>,
+    ) {
+        if self.options.rewrite_import_extensions.is_some() {
+            self.rewrite_extensions.enter_export_named_declaration(node, ctx);
+        }
+    }
+}
+
 // Transforms
 impl<'a> TypeScript<'a> {
     pub fn transform_program(&self, program: &mut Program<'a>, ctx: &mut TraverseCtx) {

crates/oxc_transformer/src/typescript/options.rs

@@ -1,6 +1,9 @@
-use std::borrow::Cow;
+use std::{borrow::Cow, fmt};
 
-use serde::Deserialize;
+use serde::{
+    de::{self, Visitor},
+    Deserialize, Deserializer,
+};
 
 use crate::context::TransformCtx;
 
@@ -45,6 +48,16 @@ pub struct TypeScriptOptions {
 
     /// Unused.
     pub optimize_const_enums: bool,
+
+    // Preset options
+    /// Modifies extensions in import and export declarations.
+    ///
+    /// This option, when used together with TypeScript's [`allowImportingTsExtension`](https://www.typescriptlang.org/tsconfig#allowImportingTsExtensions) option,
+    /// allows to write complete relative specifiers in import declarations while using the same extension used by the source files.
+    ///
+    /// When set to `true`, same as [`RewriteExtensionsMode::Rewrite`]. Defaults to `false` (do nothing).
+    #[serde(deserialize_with = "deserialize_rewrite_import_extensions")]
+    pub rewrite_import_extensions: Option<RewriteExtensionsMode>,
 }
 
 impl TypeScriptOptions {
@@ -93,6 +106,63 @@ impl Default for TypeScriptOptions {
             allow_namespaces: default_as_true(),
             allow_declare_fields: default_as_true(),
             optimize_const_enums: false,
+            rewrite_import_extensions: None,
         }
     }
 }
+
+#[derive(Debug, Clone, Default)]
+pub enum RewriteExtensionsMode {
+    /// Rewrite `.ts`/`.mts`/`.cts` extensions in import/export declarations to `.js`/`.mjs`/`.cjs`.
+    #[default]
+    Rewrite,
+    /// Remove `.ts`/`.mts`/`.cts`/`.tsx` extensions in import/export declarations.
+    Remove,
+}
+
+impl RewriteExtensionsMode {
+    pub fn is_remove(&self) -> bool {
+        matches!(self, Self::Remove)
+    }
+}
+
+pub fn deserialize_rewrite_import_extensions<'de, D>(
+    deserializer: D,
+) -> Result<Option<RewriteExtensionsMode>, D::Error>
+where
+    D: Deserializer<'de>,
+{
+    struct RewriteExtensionsModeVisitor;
+
+    impl<'de> Visitor<'de> for RewriteExtensionsModeVisitor {
+        type Value = Option<RewriteExtensionsMode>;
+
+        fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+            formatter.write_str("true, false, \"rewrite\", or \"remove\"")
+        }
+
+        fn visit_bool<E>(self, value: bool) -> Result<Self::Value, E>
+        where
+            E: de::Error,
+        {
+            if value {
+                Ok(Some(RewriteExtensionsMode::Rewrite))
+            } else {
+                Ok(None)
+            }
+        }
+
+        fn visit_str<E>(self, value: &str) -> Result<Self::Value, E>
+        where
+            E: de::Error,
+        {
+            match value {
+                "rewrite" => Ok(Some(RewriteExtensionsMode::Rewrite)),
+                "remove" => Ok(Some(RewriteExtensionsMode::Remove)),
+                _ => Err(E::custom(format!("Expected RewriteExtensionsMode is either \"rewrite\" or \"remove\" but found: {value}"))),
+            }
+        }
+    }
+
+    deserializer.deserialize_any(RewriteExtensionsModeVisitor)
+}

crates/oxc_transformer/src/typescript/rewrite_extensions.rs

@@ -0,0 +1,89 @@
+//! Rewrite import extensions
+//!
+//! This plugin is used to rewrite/remove extensions from import/export source.
+//! It is only handled source that contains `/` or `\` in the source.
+//!
+//! Based on Babel's [plugin-rewrite-ts-imports](https://github.com/babel/babel/blob/3bcfee232506a4cebe410f02042fb0f0adeeb0b1/packages/babel-preset-typescript/src/plugin-rewrite-ts-imports.ts)
+
+use oxc_ast::ast::{
+    ExportAllDeclaration, ExportNamedDeclaration, ImportDeclaration, StringLiteral,
+};
+use oxc_traverse::{Traverse, TraverseCtx};
+
+use super::options::RewriteExtensionsMode;
+
+pub struct TypeScriptRewriteExtensions {
+    mode: RewriteExtensionsMode,
+}
+
+impl TypeScriptRewriteExtensions {
+    pub fn new(mode: RewriteExtensionsMode) -> Self {
+        Self { mode }
+    }
+
+    pub fn rewrite_extensions<'a>(
+        &self,
+        source: &mut StringLiteral<'a>,
+        ctx: &mut TraverseCtx<'a>,
+    ) {
+        let value = source.value.as_str();
+        if !value.contains(|c| c == '/' || c == '\\') {
+            return;
+        }
+
+        let Some((_, extension)) = value.rsplit_once('.') else { return };
+
+        let replace = match extension {
+            "mts" => "mjs",
+            "cts" => "cjs",
+            "ts" | "tsx" => "js",
+            _ => return, // do not  rewrite or remove other unknown extensions
+        };
+
+        let value = value.trim_end_matches(extension);
+        source.value = if self.mode.is_remove() {
+            ctx.ast.atom(value.trim_end_matches('.'))
+        } else {
+            let mut value = value.to_string();
+            value.push_str(replace);
+            ctx.ast.atom(&value)
+        };
+    }
+}
+
+impl<'a> Traverse<'a> for TypeScriptRewriteExtensions {
+    fn enter_import_declaration(
+        &mut self,
+        node: &mut ImportDeclaration<'a>,
+        ctx: &mut TraverseCtx<'a>,
+    ) {
+        if node.import_kind.is_type() {
+            return;
+        }
+        self.rewrite_extensions(&mut node.source, ctx);
+    }
+
+    fn enter_export_named_declaration(
+        &mut self,
+        node: &mut ExportNamedDeclaration<'a>,
+        ctx: &mut TraverseCtx<'a>,
+    ) {
+        if node.export_kind.is_type() {
+            return;
+        }
+        if let Some(source) = node.source.as_mut() {
+            self.rewrite_extensions(source, ctx);
+        }
+    }
+
+    fn enter_export_all_declaration(
+        &mut self,
+        node: &mut ExportAllDeclaration<'a>,
+        ctx: &mut TraverseCtx<'a>,
+    ) {
+        if node.export_kind.is_type() {
+            return;
+        }
+        self.rewrite_extensions(&mut node.source, ctx);
+    }
+}

napi/transform/index.d.ts

@@ -18,7 +18,7 @@ export interface Es2015BindingOptions {
 }
 
 /** TypeScript Isolated Declarations for Standalone DTS Emit */
-function isolatedDeclaration(filename: string, sourceText: string, options: IsolatedDeclarationsOptions): IsolatedDeclarationsResult
+export declare function isolatedDeclaration(filename: string, sourceText: string, options: IsolatedDeclarationsOptions): IsolatedDeclarationsResult
 
 export interface IsolatedDeclarationsOptions {
   sourcemap: boolean
@@ -136,7 +136,7 @@ export interface SourceMap {
  * @returns an object containing the transformed code, source maps, and any
  * errors that occurred during parsing or transformation.
  */
-function transform(filename: string, sourceText: string, options?: TransformOptions | undefined | null): TransformResult
+export declare function transform(filename: string, sourceText: string, options?: TransformOptions | undefined | null): TransformResult
 
 /**
  * Options for transforming a JavaScript or TypeScript file.
@@ -230,5 +230,16 @@ export interface TypeScriptBindingOptions {
    * @default false
    */
   declaration?: boolean
+  /**
+   * Rewrite or remove TypeScript import/export declaration extensions.
+   *
+   * - When set to `rewrite`, it will change `.ts`, `.mts`, `.cts` extensions to `.js`, `.mjs`, `.cjs` respectively.
+   * - When set to `remove`, it will remove the extensions entirely.
+   * - When set to `true`, it's equivalent to `rewrite`.
+   * - When set to `false` or omitted, no changes will be made to the extensions.
+   *
+   * @default false
+   */
+  rewriteImportExtensions?: 'rewrite' | 'remove' | boolean
 }
 

napi/transform/src/options.rs

@@ -1,9 +1,11 @@
 use std::path::PathBuf;
 
+use napi::Either;
 use napi_derive::napi;
 
 use oxc_transformer::{
-    ArrowFunctionsOptions, ES2015Options, ReactJsxRuntime, ReactOptions, TypeScriptOptions,
+    ArrowFunctionsOptions, ES2015Options, ReactJsxRuntime, ReactOptions, RewriteExtensionsMode,
+    TypeScriptOptions,
 };
 
 #[napi(object)]
@@ -22,6 +24,16 @@ pub struct TypeScriptBindingOptions {
     ///
     /// @default false
     pub declaration: Option<bool>,
+    /// Rewrite or remove TypeScript import/export declaration extensions.
+    ///
+    /// - When set to `rewrite`, it will change `.ts`, `.mts`, `.cts` extensions to `.js`, `.mjs`, `.cjs` respectively.
+    /// - When set to `remove`, it will remove `.ts`/`.mts`/`.cts`/`.tsx` extension entirely.
+    /// - When set to `true`, it's equivalent to `rewrite`.
+    /// - When set to `false` or omitted, no changes will be made to the extensions.
+    ///
+    /// @default false
+    #[napi(ts_type = "'rewrite' | 'remove' | boolean")]
+    pub rewrite_import_extensions: Option<Either<bool, String>>,
 }
 
 impl From<TypeScriptBindingOptions> for TypeScriptOptions {
@@ -36,6 +48,22 @@ impl From<TypeScriptBindingOptions> for TypeScriptOptions {
             allow_namespaces: options.allow_namespaces.unwrap_or(ops.allow_namespaces),
             allow_declare_fields: options.allow_declare_fields.unwrap_or(ops.allow_declare_fields),
             optimize_const_enums: false,
+            rewrite_import_extensions: options.rewrite_import_extensions.and_then(|value| {
+                match value {
+                    Either::A(v) => {
+                        if v {
+                            Some(RewriteExtensionsMode::Rewrite)
+                        } else {
+                            None
+                        }
+                    }
+                    Either::B(v) => match v.as_str() {
+                        "rewrite" => Some(RewriteExtensionsMode::Rewrite),
+                        "remove" => Some(RewriteExtensionsMode::Remove),
+                        _ => None,
+                    },
+                }
+            }),
         }
     }
 }

tasks/transform_conformance/babel.snap.md

@@ -1,6 +1,6 @@
 commit: 3bcfee23
 
-Passed: 309/1021
+Passed: 310/1021
 
 # All Passed:
 * babel-plugin-transform-optional-catch-binding
@@ -2101,7 +2101,7 @@ failed to resolve query: failed to parse the rest of input: ...''
 
 
 
-# babel-preset-typescript (4/10)
+# babel-preset-typescript (5/10)
 * jsx-compat/ts-invalid/input.ts
   x Expected `>` but found `/`
    ,-[tasks/coverage/babel/packages/babel-preset-typescript/test/fixtures/jsx-compat/ts-invalid/input.ts:1:7]
@@ -2141,9 +2141,6 @@ failed to resolve query: failed to parse the rest of input: ...''
   | rebuilt        : SymbolId(0): SymbolFlags(FunctionScopedVariable)
 
 
-* opts/rewriteImportExtensions/input.ts
-
-
 
 # babel-plugin-transform-typescript (41/152)
 * cast/as-expression/input.ts

tasks/transform_conformance/oxc.snap.md

@@ -1,9 +1,10 @@
 commit: 3bcfee23
 
-Passed: 10/39
+Passed: 11/40
 
 # All Passed:
 * babel-plugin-transform-optional-catch-binding
+* babel-preset-typescript
 
 
 # babel-plugin-transform-nullish-coalescing-operator (0/1)

tasks/transform_conformance/tests/babel-preset-typescript/test/fixtures/removeImportExtensions/input.ts

@@ -0,0 +1,11 @@
+import "./a.ts";
+import "./a.mts";
+import "./a.cts";
+import "./react.tsx";
+// .mtsx and .ctsx are not valid and should not be transformed.
+import "./react.mtsx";
+import "./react.ctsx";
+import "a-package/file.ts";
+// Bare import, it's either a node package or remapped by an import map
+import "soundcloud.ts";
+import "ipaddr.js";

tasks/transform_conformance/tests/babel-preset-typescript/test/fixtures/removeImportExtensions/options.json

@@ -0,0 +1,4 @@
+{
+  "sourceType": "module",
+  "presets": [["typescript", { "rewriteImportExtensions": "remove" }]]
+}

tasks/transform_conformance/tests/babel-preset-typescript/test/fixtures/removeImportExtensions/output.js

@@ -0,0 +1,11 @@
+import "./a";
+import "./a";
+import "./a";
+import "./react";
+// .mtsx and .ctsx are not valid and should not be transformed.
+import "./react.mtsx";
+import "./react.ctsx";
+import "a-package/file";
+// Bare import, it's either a node package or remapped by an import map
+import "soundcloud.ts";
+import "ipaddr.js";