Need a way to turn off TS1479 when require(ESM) is supported

[jfirebaugh]

🔍 Search Terms

TS1479 is "The current file is a CommonJS module whose imports will produce 'require' calls; however, the referenced file is an ECMAScript module and cannot be imported with 'require'. Consider writing a dynamic import call instead."

But require(ESM) is now supported -- under --experimental-require-module in node 20.x and 22.x and by default in node 23.x -- providing that the module graph contains no top-level await. So TypeScript needs a way to disable TS1479 when a user can assert that this is the case.

✅ Viability Checklist

• [x] This wouldn't be a breaking change in existing TypeScript/JavaScript code
• [x] This wouldn't change the runtime behavior of existing JavaScript code
• [x] This could be implemented without emitting different JS based on the types of the expressions
• [x] This isn't a runtime feature (e.g. library functionality, non-ECMAScript syntax with JavaScript output, new syntax sugar for JS, etc.)
• [x] This isn't a request to add a new utility type: https://github.com/microsoft/TypeScript/wiki/No-New-Utility-Types
• [x] This feature would agree with the rest of our Design Goals: https://github.com/Microsoft/TypeScript/wiki/TypeScript-Design-Goals

⭐ Suggestion

"module": "nodenext" should disable TS1479.

📃 Motivating Example

Prototype blog post announcement:

TypeScript now supports require(ESM)

In CJS packages whose tsconfig specifies "module": "nodenext", TypeScript will no longer produce an error when requiring a module known to be ESM.

For example, the following will now work: module_a/package.json:

{
  ...
  "type": "module"
}

module_a/foo.js:

export const foo = "foo"

module_a/package.json: (no "type": "module")

module_b/tsconfig.json:

{
  "compilerOptions": {
    "module": "nodenext"
  }
}

module_b/foo.ts:

import foo from "module_a/foo"

💻 Use Cases

1. What do you want to use this for? Interoperability between ESM and CJS.
2. What shortcomings exist with current approaches? TypeScript does not allow CJS to require(ESM), even when it is supported by node.
3. What workarounds are you using in the meantime? Have to avoid doing that.