[V6] `module` defaults is not `esnext`

🔎 Search Terms

"module", "default", "esnext", "v6"

🕗 Version & Regression Information

This changed between versions V5 and V6

⏯ Playground Link

This isn't an issue in Playground, because you're required to enter a value for the module.

https://www.typescriptlang.org/play/?#code/FASwtgDg9gTgLgAgGZSsmUwIEQDoD0KUuAVgM5QB22CA7iHABYIDeCcAnhAKYBcO5KjQC+AbmDAAxlQoAbbrllQA5gAoiASlFA

💻 Code

• package.json

  {
    "name": "testcase",
    "version": "1.0.0",
    "type": "module",
    "dependencies": {
      "typescript": "6.0.2"
    }
  }
  

• index.ts

  import foo from "./foo.json" with { type: "json" };
  
  console.log(foo);
  

1. npm install
2. npc tsc index.ts

🙁 Actual behavior

index.ts:1:30 - error TS2823: Import attributes are only supported when the '--module' option is set to 'esnext', 'node18', 'node20', 'nodenext', or 'preserve'.

1 import foo from "./foo.json" with { type: "json" };
                               ~~~~~~~~~~~~~~~~~~~~~

🙂 Expected behavior

No error because module defaults to esnext.

Additional information about the issue

In Announcing TypeScript 6.0, it says module defaults to esnext: Similarly, the new default module is esnext, acknowledging that ESM is now the dominant module format.

But in TSConfig Reference, it's CommonJS if target is ES5; ES6/ES2015 otherwise.

In the code, I don't think the default value is esnext. Otherwise, we wouldn't be getting the TS2823 error.