Revert "fix(cli): Fix configuration reuse issue in swcDir() by deep clone"

.changeset/big-pillows-learn.md

@@ -0,0 +1,5 @@
+---
+"@swc/cli": patch
+---
+
+Revert "fix(cli): Fix configuration reuse issue in swcDir() by deep clone"

packages/cli/src/swc/dir.ts

@@ -5,7 +5,7 @@ import { stderr } from "process";
 import { format } from "util";
 import { CompileStatus } from "./constants";
 import { Callbacks, CliOptions } from "./options";
-import { exists, getDest, mapTsExt, deepClone } from "./util";
+import { exists, getDest, mapTsExt } from "./util";
 import handleCompile from "./dirWorker";
 import {
     globSources,
@@ -401,16 +401,12 @@ export default async function dir({
     swcOptions: Options;
     callbacks?: Callbacks;
 }) {
-    // Deep clone the options to ensure full isolation between multiple calls
-    const clonedCliOptions = deepClone(cliOptions);
-    const clonedSwcOptions = deepClone(swcOptions);
+    const { watch } = cliOptions;
 
-    const { watch } = clonedCliOptions;
-
-    await beforeStartCompilation(clonedCliOptions);
-    await initialCompilation(clonedCliOptions, clonedSwcOptions, callbacks);
+    await beforeStartCompilation(cliOptions);
+    await initialCompilation(cliOptions, swcOptions, callbacks);
 
     if (watch) {
-        await watchCompilation(clonedCliOptions, clonedSwcOptions, callbacks);
+        await watchCompilation(cliOptions, swcOptions, callbacks);
     }
 }

packages/cli/src/swc/dirWorker.ts

@@ -1,7 +1,7 @@
 import slash from "slash";
 import { dirname, relative } from "path";
 import { CompileStatus } from "./constants";
-import { compile, getDest, mapDtsExt, mapTsExt, deepClone } from "./util";
+import { compile, getDest, mapDtsExt, mapTsExt } from "./util";
 import { outputResult } from "./compile";
 
 import type { Options } from "@swc/core";
@@ -15,45 +15,29 @@ export default async function handleCompile(opts: {
     swcOptions: Options;
     outFileExtension?: string;
 }) {
-    // Create a deep clone of the options to prevent shared references
-    const clonedOpts = deepClone(opts);
-
     const dest = getDest(
-        clonedOpts.filename,
-        clonedOpts.outDir,
-        clonedOpts.cliOptions.stripLeadingPaths,
-        `.${clonedOpts.outFileExtension ?? mapTsExt(clonedOpts.filename)}`
+        opts.filename,
+        opts.outDir,
+        opts.cliOptions.stripLeadingPaths,
+        `.${opts.outFileExtension ?? mapTsExt(opts.filename)}`
     );
-    const sourceFileName = slash(relative(dirname(dest), clonedOpts.filename));
-
-    // Create a fresh copy of the swcOptions
-    const options = deepClone(clonedOpts.swcOptions);
+    const sourceFileName = slash(relative(dirname(dest), opts.filename));
 
-    // Set sourceFileName in the options
-    options.sourceFileName = sourceFileName;
+    const options = { ...opts.swcOptions, sourceFileName };
 
-    // Ensure we have the right extension for output files
-    // Instead of directly setting on module.outFileExtension (which might not exist in the type),
-    // we'll pass it separately to the compile function
-
-    const result = await compile(
-        clonedOpts.filename,
-        options,
-        clonedOpts.sync,
-        dest
-    );
+    const result = await compile(opts.filename, options, opts.sync, dest);
 
     if (result) {
         const destDts = getDest(
-            clonedOpts.filename,
-            clonedOpts.outDir,
-            clonedOpts.cliOptions.stripLeadingPaths,
-            `.${mapDtsExt(clonedOpts.filename)}`
+            opts.filename,
+            opts.outDir,
+            opts.cliOptions.stripLeadingPaths,
+            `.${mapDtsExt(opts.filename)}`
         );
         const destSourcemap = dest + ".map";
         await outputResult({
             output: result,
-            sourceFile: clonedOpts.filename,
+            sourceFile: opts.filename,
             destFile: dest,
             destDtsFile: destDts,
             destSourcemapFile: destSourcemap,

packages/cli/src/swc/util.ts

@@ -4,29 +4,6 @@ import { mkdirSync, writeFileSync, promises } from "fs";
 import { dirname, extname, join, relative } from "path";
 import { stderr } from "process";
 
-/**
- * Deep clone an object to ensure no shared references
- * @param obj The object to clone
- * @returns A new deep-cloned object
- */
-export function deepClone<T>(obj: T): T {
-    if (obj === null || typeof obj !== "object") {
-        return obj;
-    }
-
-    if (Array.isArray(obj)) {
-        return (obj.map(item => deepClone(item)) as unknown) as T;
-    }
-
-    const result = {} as T;
-    for (const key in obj) {
-        if (Object.prototype.hasOwnProperty.call(obj, key)) {
-            result[key] = deepClone(obj[key]);
-        }
-    }
-    return result;
-}
-
 export async function exists(path: string): Promise<boolean> {
     let pathExists = true;
     try {
@@ -66,22 +43,11 @@ export async function compile(
     sync: boolean,
     outputPath: string | undefined
 ): Promise<swc.Output | void> {
-    // Deep clone the options to ensure we don't have any shared references
-    opts = deepClone({
+    opts = {
         ...opts,
-    });
-
+    };
     if (outputPath) {
         opts.outputPath = outputPath;
-
-        // Extract the extension from the output path to ensure module resolution uses it
-        const ext = extname(outputPath);
-        if (ext && opts.module && typeof opts.module === "object") {
-            // Force the module to use the correct extension for import path resolution
-            // This explicit setting helps ensure we don't reuse cached module config
-            // @ts-ignore: Adding a custom property that might not be in the type definition
-            opts.module.forcedOutputFileExtension = ext.slice(1); // Remove the leading dot
-        }
     }
 
     try {