Generated code is not transpiled by rollup-plugin-babel to ES5 with vue plugin

[cloudever]

Expected behavior

Keyword const should be transpiled to var because I've applied .browserslistrc with ie 9 for Babel 7.
It seems to be that code from vue-component-compiler is not transpiled to ES5 partially.

https://github.com/vuejs/vue-component-compiler/blob/afa1cd440123e2e0c195908c1e15935273ac64a9/src/assembler.ts#L304-L307

"rollup-plugin-babel": "^4.0.3",
"rollup-plugin-vue": "^4.3.2",

Actual behavior

I get following code that contains const not var!

	var __vue_staticRenderFns__ = [];
	__vue_render__._withStripped = true;

	  /* style */
	  const __vue_inject_styles__ = undefined;
	  /* scoped */
	  const __vue_scope_id__ = undefined;
	  /* module identifier */
	  const __vue_module_identifier__ = undefined;
	  /* functional template */
	  const __vue_is_functional_template__ = false;
	  /* component normalizer */
	  function __vue_normalize__(
	    template, style, script$$1,
	    scope, functional, moduleIdentifier,
	    createInjector, createInjectorSSR
	  ) {
	    const component = (typeof script$$1 === 'function' ? script$$1.options : script$$1) || {};

Steps to reproduce the behavior

Create babel.config.js

module.exports = (api) => {
  api.cache(api.env('development'));

  const presets = [
    ['@babel/preset-env', {
      modules: false,
      useBuiltIns: false,
      forceAllTransforms: true,
    }],
  ];

  const plugins = [
    '@babel/plugin-proposal-export-default-from',
    '@babel/plugin-proposal-export-namespace-from',
    '@babel/plugin-proposal-class-properties',
    '@babel/plugin-proposal-object-rest-spread',
    ['@babel/plugin-transform-runtime', {
      corejs: 2,
      helpers: true,
      regenerator: false,
    }],
  ];

  return {
    presets,
    plugins,
  };
};

Apply plugins

export default () => [
  vue({
    compileTemplate: true,
    css: false,
  }),
  babel({
    exclude: [/\/core-js\//],
    runtimeHelpers: true,
  }),
  css(),
  replace({
    'process.env.NODE_ENV': JSON.stringify(process.env.NODE_ENV),
  }),
  resolve(),
  commonjs(),
].filter(Boolean);

And .browserslistrc

> 1%
last 2 versions
ie 9

[Andarist]

From what I remember babel ignores node_modules by default now, so you need to explicitly ask it to transpile them.

[loganfsmyth]

Are the files .vue? If so, you need to tell the plugin to process those.

Not related to your question, but FYI api.cache(api.env('development')); makes no sense. What that is saying is, re-evaluate your module.exports config function and every preset/plugin it references, for every single file, when doing a non-development build. That's essentially just making your production builds slower for no reason.

[cloudever]

Are the files .vue? If so, you need to tell the plugin to process those.

Not related to your question, but FYI api.cache(api.env('development')); makes no sense. What that is saying is, re-evaluate your module.exports config function and every preset/plugin it references, for every single file, when doing a non-development build. That's essentially just making your production builds slower for no reason.

Babel 7.1.2 force me to add api.cache expression

[loganfsmyth]

Fair. All you need is api.cache(true) though. No need to call api.env('development'). I'll see what I can do to make that clearer.

[ghettovoice]

@cloudever try to add extensions option to rollup-plugin-babel options:

// plugins 
...
babel({
  runtimeHelpers: true,
  sourceMap: true,
  extensions: ['.js', '.jsx', '.es6', '.es', '.mjs', '.vue'],
}),
...

I had the same issue after upgrade to the latest versions of rollup-plugin-vue, rollup-plugin-babel & etc.
and this options resolved it for me.

[cloudever]

@ghettovoice Did the trick thank's