PreflightCheck Error

[zsky]

The code below emitted a error, because transpiled code with babel had no matching condition

if (check.match(/\/helpers\/(esm\/)?inherits/)) helpers = RUNTIME;
else if (~check.indexOf('function _inherits')) helpers = INLINE;
else if (~check.indexOf('babelHelpers')) helpers = EXTERNAL;
else {
	ctx.error(UNEXPECTED_ERROR);
}

babel version: 7.0.0-beta.47
the output code was

import _classCallCheck from "/path/to/node_modules/@babel/runtime/helpers/builtin/es6/classCallCheck";
import _inherits from "/path/to/node_modules/@babel/runtime/helpers/builtin/es6/inherits";
import _possibleConstructorReturn from "/path/to/node_modules/@babel/runtime/helpers/builtin/es6/possibleConstructorReturn";
import _getPrototypeOf from "/path/to/node_modules/@babel/runtime/helpers/builtin/es6/getPrototypeOf";

var Foo =
/*#__PURE__*/
function (_Bar) {
  function Foo() {
    _classCallCheck(this, Foo);

    return _possibleConstructorReturn(this, _getPrototypeOf(Foo).apply(this, arguments));
  }

  _inherits(Foo, _Bar);

  return Foo;
}(Bar);

;
export default Foo;

I tried babel 7.1.2, also got error

[Andarist]

Could u paste in your rollup & babel configs? I think you are relaying on babel's removed option

[zsky]

I think the option useESModules of @babel/plugin-transform-runtime caused the problem.

I used https://github.com/vuejs/vue-cli to create the project, my bable config:

module.exports = {
  presets: ['@vue/app']
};

my rollup config:

import globby from 'globby';
import vue from 'rollup-plugin-vue';
import css from 'rollup-plugin-css-only';
import babel from 'rollup-plugin-babel';

const files = globby.sync(['packages/**']);

export default files.map((file) => {
  return {
    input: file,
    output: {
      file: file.replace('packages', 'dist').replace('.vue', '.js'),
      format: 'cjs'
    },
    plugins: [vue({ css: false }), css(), babel()],
    external: (id) => {
      return id.startsWith('.') || id === 'vue';
    }
  };
});

[Andarist]

Could you file an issue (or check if there is any already about it) in vue-cli repo? They have a little bit outdated dependencies - https://github.com/vuejs/vue-cli/blob/528c46507a21b76f12bc416d98f9b04c0076cb50/packages/%40vue/babel-preset-app/package.json#L24-L30

For the time being it seems that you should downgrade your rollup-plugin-babel to 4.0.0-beta.7

[zsky]

They had upgraded recently: vuejs/vue-cli#2642
But even if I upgraded the babel, I still have this error. #268 said preflightCheck will be removed，how long will it takes?

[Andarist]

Could u prepare a repro case? What kind of an error do you see? What is the output code?

[zsky]

I made a minimal repo to reproduce:

git clone [email protected]:zsky/rollup-plugin-babel-issue267.git
cd rollup-plugin-babel-issue267
npm i
npm run build

Then outputed a error:

(babel plugin) Error: An unexpected situation arose.

I logged the code, the _inherits:

import _inherits from "@babel/runtime/helpers/es6/inherits";

[Andarist]

The installed @vue/[email protected] has still outdated babel dependencies.

[zsky]

I changed the babel config, set useESModules false, solved my problem.