@swc/cli seems to reuse config somewhere under the hood

Describe the bug

When invoking swcDir() programmatically in the same process for two separate builds (ESM then CommonJS), the second call seems to reuse some parts of the config. As a result, even though I pass swcOptions.module.outFileExtension: 'cjs' on the second run, all import-path rewrites still use .mjs. If I comment out the ESM build, the CJS build works correctly—but running both back-to-back, the first invocation “wins” and contaminates the second somehow.

Input code

import path from "node:path";
import { swcDir } from "@swc/cli";
import { toMerged } from "es-toolkit";

export async function compileSwc() {
  const defaultOptions = {
    cliOptions: {
      outDir: path.join("dist", "es"),
      filenames: ["src"],
      extensions: [".js", ".jsx", ".cjs", ".mjs"],
      stripLeadingPaths: true,
    },
    swcOptions: {
      jsc: {
        parser: {
          syntax: "ecmascript",
        },
        baseUrl: path.resolve("src"),
      },
      module: { type: "es6", resolveFully: true, outFileExtension: "mjs" },
    },
  };

  // Config for ES6 modules output
  const swcModulesConfig = defaultOptions;

  // Merge options for CommonJS output
  const swcCommonJSConfig = toMerged(defaultOptions, {
    cliOptions: {
      outDir: path.join("dist", "cjs"),
      outFileExtension: "cjs",
    },
    swcOptions: {
      module: { type: "commonjs", outFileExtension: "cjs" },
    },
  });

  console.log("Compiling esm.");
  await swcDir(swcModulesConfig);

  console.log("Compiling CommonJS.");
  await swcDir(swcCommonJSConfig);
}

Config

Link to the code that reproduces this issue

https://codesandbox.io/p/devbox/w9lwrg?file=%2Fdist%2Fcjs%2Findex.cjs

SWC Info output

No response

Expected behavior

In the dist/cjs folder the import paths should be rewritten to use '.cjs' extensions

Actual behavior

In the dist/cjs folder the import paths are rewritten with '.mjs' extensions

Version

"@swc/cli": "^0.7.3", "@swc/core": "^1.11.21"

Additional context

No response

Donny/강동윤 (@kdy1)

Donny/강동윤 (@kdy1) if you want i can take a look and try to reproduce and propose a fix with your permission!

It would be nice, thank you!

Donny/강동윤 (@kdy1)

Donny/강동윤 (@kdy1) the issue is realted to this repo https://github.com/swc-project/pkgs so we have to fix this in pkgs repo so should I create the PR directly in pkgs or something else??

You should send a PR to pkgs repo I guess

Donny/강동윤 (@kdy1)

Done Donny/강동윤 (@kdy1) but there are some problems we should discuss in that PR

fix(cli): Fix configuration reuse issue in swcDir() by deep clone (#95)

हिमांशु (@CodeMan62)

Great! Thanks for fixing this so quickly! हिमांशु (@CodeMan62) Donny/강동윤 (@kdy1) 🙌
Any idea when this will be released?

I published a new version

Thomas Mattheussen (@thomasmattheussen)

Thomas Mattheussen (@thomasmattheussen) the new version is out check out if you see the bug is still there or see any bug or issue just create a PR I would love to work on that ❤

I think something went wrong with publishing. I get this error now:

node:internal/modules/esm/resolve:204
  const resolvedOption = FSLegacyMainResolve(pkgPath, packageConfig.main, baseStringified);
                         ^

Error: Cannot find package '/Users/tsmn02/Desktop/chameleon-another-alt/packages/chameleon-react/node_modules/@swc/cli/lib/swc/index.js' imported from /Users/tsmn02/Desktop/chameleon-another-alt/packages/chameleon-react/tools/compile/swc.mjs
    at legacyMainResolve (node:internal/modules/esm/resolve:204:26)
    at packageResolve (node:internal/modules/esm/resolve:778:12)
    at moduleResolve (node:internal/modules/esm/resolve:854:18)
    at defaultResolve (node:internal/modules/esm/resolve:984:11)
    at ModuleLoader.defaultResolve (node:internal/modules/esm/loader:685:12)
    at #cachedDefaultResolve (node:internal/modules/esm/loader:634:25)
    at ModuleLoader.resolve (node:internal/modules/esm/loader:617:38)
    at ModuleLoader.getModuleJobForImport (node:internal/modules/esm/loader:273:38)
    at ModuleJob._link (node:internal/modules/esm/module_job:135:49) {
  code: 'ERR_MODULE_NOT_FOUND'
}

Node.js v22.14.0
 ELIFECYCLE  Command failed with exit code 1.

I assume this is due to #96

When I check my node_modules folder, the /lib folder is not there in the @swc/cli package.

हिमांशु (@CodeMan62)

I think something went wrong with publishing.

Okay, that seems fixed with 0.7.5 👍

हिमांशु (@CodeMan62) But now I also get this issue: #101

Reopening as #95 is reverted.

Donny/강동윤 (@kdy1)

will investigate it again and make sure to fix it Donny/강동윤 (@kdy1)

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@swc/cli seems to reuse config somewhere under the hood #97

Describe the bug

Input code

Config

Link to the code that reproduces this issue

SWC Info output

Expected behavior

Actual behavior

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@swc/cli seems to reuse config somewhere under the hood #97

Description

Describe the bug

Input code

Config

Link to the code that reproduces this issue

SWC Info output

Expected behavior

Actual behavior

Version

Additional context

Activity

CodeMan62 commented on Apr 23, 2025

kdy1 commented on Apr 23, 2025

CodeMan62 commented on Apr 24, 2025

kdy1 commented on Apr 24, 2025

CodeMan62 commented on Apr 25, 2025

thomasmattheussen commented on May 6, 2025

kdy1 commented on May 6, 2025

CodeMan62 commented on May 6, 2025

thomasmattheussen commented on May 7, 2025

thomasmattheussen commented on May 8, 2025

kdy1 commented on May 12, 2025

CodeMan62 commented on May 12, 2025

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