Slow import using allowJs option

[Pavel-Boyazov]

Search Terms

Slow import
Long time import

Expected Behavior

Speed regardless of the indication of allowJs

Actual Behavior

Import without allowJs option takes about 0.5 ms
Import with allowJs option is true takes about 43 ms

Steps to reproduce the problem

1. Create commonJS file with other files imports
2. Compare speed with allowJs using and without

Minimal reproduction

const fs = require("fs");

fs.writeFileSync(`${__dirname}/t1.cjs`, "module.exports = 1");

console.time(-1);

const t = require("./t1.cjs");

console.timeEnd(-1);

fs.unlinkSync(`${__dirname}/t1.cjs`);

Specifications

• ts-node version: v10.9.2
• node version: v20.16.0
• TypeScript version: v5.6.2
• tsconfig.json, if you're using one:

{
  "compilerOptions": { 
    "allowJs": true,
  },
}

OR

{}

• package.json:

{
	"devDependencies": {
		"ts-node": "^10.9.2",
		"typescript": "^5.6.2"
	},
}

• Operating system and version: MacOS 14.1.2
• If Windows, are you using WSL or WSL2?: