Environment

Local ESLint version: 9.13.0

What parser are you using?

Default (Espree)

What did you do?

No "type" declared inside package.json.

Three blank config files:

• eslint.config.cjs
• eslint.config.js
• eslint.config.mjs

What did you expect to happen?

ESLint should give the same output no matter which of the three blank config files are used.

What actually happened?

• npx eslint -c eslint.config.cjs: no output
• npx eslint -c eslint.config.js: no output
• npx eslint -c eslint.config.mjs: the following error message was displayed:

Oops! Something went wrong! :(

ESLint: 9.13.0

TypeError: Config (unnamed): Unexpected undefined config at user-defined index 0.

Link to Minimal Reproducible Example

https://github.com/abrahamguo/repro/tree/eslint-no-export

Participation

• I am willing to submit a pull request for this issue.

Additional comments

No response