How to modify babel-preset-env configuration?

• Laravel Mix Version: 1.4.2
• Node Version (node -v): v8.4.0
• NPM Version (npm -v): 5.3.0
• OS: Mac

Description:

In src/config.js there is:

        babel: function () {
            let options = {};

            tap(Mix.paths.root('.babelrc'), babelrc => {
                if (File.exists(babelrc)) {
                    options = JSON.parse(File.find(babelrc).read());
                }
            });

            let defaultOptions = {
                cacheDirectory: true,
                presets: [
                    ['env', {
                        'modules': false,
                        'targets': {
                            'browsers': ['> 2%'],
                            uglify: true
                        }
                    }]
                ]
            };

            if (this.react) {
                defaultOptions.presets.push('react');
            }

            return webpackMerge.smart(defaultOptions, options);
        },

Steps To Reproduce:

In my .babelrc I have

{
  "presets": [
    ["env", {
        "targets": {
            "browsers": ["> 5%"],
            "uglify": false
        }
    }]
  ]
}

However, this is just concatenating this as another ‘env’ preset and it isn’t being used. How can I modify the original env preset?

[darrena092]

This essentially makes Laravel Mix no longer useful for my case as it seems to not be transpiling for IE11 now which clients are still requesting support for. IMO this feature should be pretty high priority - there will always be edge cases where the > 2% target is not appropriate.

[atomita]

Example of update the merge strategy.

let _ = require('lodash'),
    webpackMerge = require('webpack-merge'),
    smart = webpackMerge.smart;

webpackMerge.smart = function(a, b) {
    var r = smart.call(webpackMerge, a, b);

    if (! b.presets) {
        return r;
    }

    let i = _.findIndex(b.presets, [0, 'env']);
    if (i < 0) {
        return r;
    }

    let j = _.findIndex(r.presets, [0, 'env']);
    if (j < 0) {
        j = r.presets.length;
        r.presets.push(['env']);
    }

    r.presets[j][1] = _.defaults({}, b.presets[i][1] || {}, r.presets[j][1] || {});

    return r;
};

let mix = require('laravel-mix');

mix.js('resources/assets/js/app.js', 'public/js')
   .sass('resources/assets/sass/app.scss', 'public/css');