Pre-bundling questions

[anncwb]

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• Read the docs.
• Use Vite >=2.0. (1.x is no longer supported)

Describe the bug

In beta.36, import moment. It is a function

import moment from 'moment'

console.log(moment)

=>

ƒ hooks() {
 return hookCallback.apply(null, arguments);
 }

In beta.49, import moment. It is a Object

import moment from 'moment'

console.log(moment)

=>

 {__esModule: true}
default: (...)
__esModule: true
get default: () => moment_default
__proto__: Object
}

Is this expected or a bug？Why the two results are inconsistent

Reproduction

• git clone https://github.com/vbenjs/vite-moment-bug
• yarn && yarn serve
• Switch the vite version to vite.49 and re-execute the above steps

System Info

• vite version: bete.49
• Operating System: mac
• Node version: 12
• Package manager (npm/yarn/pnpm) and version:yarn

[yyx990803]

Sigh... this is really messed up:

• moment defines jsnext:main which points to a ESM file (dist/moment.js)
• Inside the ESM file, it uses some weird hack: var aliasedRequire = require then calls that aliasedRequire as if it would work in ESM... (it probably works in webpack 🤷 )
• esbuild is a bit too smart and notices that moment is actually calling require even when it's aliased, so it still wraps the moment ESM build as a CommonJS module
• However since moment declares that its entry is ESM (and does have export default in it), Vite thinks it does not need CommonJS interop.

[anncwb]

thank

[techird]

Provide a temperary workaround here:

1. Alias moment to the hooked version:

// vite.config.js

export default {
  // other config
  resolve: {
    alias: [
      // make moment to be a resolvable ESM
      { find: /^moment$/, replacement: path.resolve(__dirname, './alias/moment.js') },
    ],
  },
}

2. Implement the hooked moment.js

// absolute path to moment in node_modules
import moment from '../../node_modules/moment';

export const {
  fn,
  min,
  max,
  now,
  utc,
  unix,
  months,
  isDate,
  locale,
  invalid,
  duration,
  isMoment,
  weekdays,
  parseZone,
  localeData,
  isDuration,
  monthsShort,
  weekdaysMin,
  defineLocale,
  updateLocale,
  locales,
  weekdaysShort,
  normalizeUnits,
  relativeTimeRounding,
  relativeTimeThreshold,
  calendarFormat,
} = moment;

export default moment;