How to prevent moment.js from loading locales with webpack?

Question

The code require('./locale/' + name) can use every file in the locale dir. So webpack includes every file as module in your bundle. It cannot know which language you are using.

There are two plugins that are useful to give webpack more information about which module should be included in your bundle: ContextReplacementPlugin and IgnorePlugin.

require('./locale/' + name) is called a context (a require which contains an expression). webpack infers some information from this code fragment: A directory and a regular expression. Here: directory = ".../moment/locale" regular expression = /^.*$/. So by default every file in the locale directory is included.

The ContextReplacementPlugin allows to override the inferred information i.e. provide a new regular expression (to choose the languages you want to include).

Another approach is to ignore the require with the IgnorePlugin.

Here is an example:

var webpack = require("webpack");
module.exports = {
  // ...
  plugins: [
    new webpack.ContextReplacementPlugin(/moment[\/\\]locale$/, /de|fr|hu/)
    // new webpack.IgnorePlugin(/^\.\/locale$/, /moment$/)
  ]
};

In our project, I include moment like this: import moment from 'moment/src/moment'; and that seems to do the trick. Our usage of moment is very simple though, so I'm not sure if there will be any inconsistencies with the SDK. I think this works because WebPack doesn't know how to find the locale files statically, so you get a warning (that's easy to hide by adding an empty folder at moment/src/lib/locale/locale) but no locale includes.

UPDATE: 2021
There are many other libs that you may want to checkout:

• https://date-fns.org
• https://github.com/iamkun/dayjs

ORIGINAL ANSWER:
Seems like the proper modular moment library will never come up However, I just ended up of using https://github.com/ksloan/moment-mini like import * as moment from 'moment-mini';

Based on Adam McCrmick's answer, you were close, change your alias to:

resolve: {
    alias: {
        moment: 'moment/src/moment'
    },
},

With webpack2 and recent versions of moment you can do:

import {fn as moment} from 'moment'

And then in webpack.config.js you do:

resolve: {
    packageMains: ['jsnext:main', 'main']
}