[2.0] Invalid configuration file `...`: parent.eval is not a function

Environments:

• Prettier Version: 2.0.0
• Running Prettier via: CLI
• Runtime: Node 10.10 AND 12.16
• Operating System: mac osx

Steps to reproduce:

Once updating to 2.0, all my prettier commands are failing, across all my projects. It’s always the same error:

[error] Invalid configuration file `packages/config/src/configs/babel.ts`: parent.eval is not a function

I tried the following command on Node 10 AND 12, and it’s the same error.

npx prettier packages/config/src/configs/babel.ts --write

Also fails with or without --write.

My prettier.config.js:

module.exports = {
  arrowParens: 'always',
  bracketSpacing: true,
  endOfLine: 'lf',
  jsxBracketSameLine: false,
  printWidth: 100,
  proseWrap: 'always',
  semi: true,
  singleQuote: true,
  tabWidth: 2,
  trailingComma: 'all',
  useTabs: false,
};

Expected behavior:

It works.

Actual behavior:

It doesn’t.

[wKovacs64]

Same. Seems to be an issue with the JavaScript (prettier.config.js) method of configuration. Changing my config to JSON in .prettierrc works.

[thorn0]

2.0.1 is on npm 🎉