index.js

'use strict';

var path = require('path');

var obj = {};
function isType(s, typeString) {
    return obj.toString.call(s) === '[object ' + typeString + ']';
}

function isObject(s) {
    return isType(s, 'Object');
}

function validateBoolOption(name, value, defaultValue) {
    if (typeof value === 'undefined') {
        value = defaultValue;
    }

    if (typeof value !== 'boolean') {
        throw new Error('Preset zuzuche: "' + name + '" option must be a boolean.');
    }

    return value;
}

var assign = Object.assign;

var DEFAULT_ENV_OPTIONS = {
    targets: {},
    ignoreBrowserslistConfig: false, // 忽略browserslist文件配置
    useBuiltIns: false, // 怎么运用 polyfill
    modules: false, // 是否转译module syntax，默认是 commonjs
    debug: false, // 是否输出启用的plugins列表
    exclude: ['transform-typeof-symbol'] // 强制不启用的 plugins
};

var DEFAULT_TRANSFORM_RUNTIME_OPTIONS = {
    corejs: 3,
    version: require('@babel/runtime/package.json').version,
    helpers: true,
    regenerator: true,
    useESModules: true,
    absoluteRuntime: true
};

var DEFAULT_REACT_OPTIONS = {
    useBuiltIns: true
};

module.exports = function (context, options) {
    var ENV = process.env.BABEL_ENV || process.env.NODE_ENV;
    var isEnvProduction = ENV === 'production';
    var isEnvDevelopment = ENV === 'development';

    // ====================
    // presets config
    var envOptions = (options && isObject(options.env)) ?
        assign({}, DEFAULT_ENV_OPTIONS, options.env) :
        assign({}, DEFAULT_ENV_OPTIONS);

    var reactOptions = (options && isObject(options.react)) ?
        assign({}, DEFAULT_REACT_OPTIONS, options.react) :
        assign({}, DEFAULT_REACT_OPTIONS);
    reactOptions.development = isEnvDevelopment;

    var presets = [
        [require('@babel/preset-env').default, envOptions],
        [require('@babel/preset-react').default, reactOptions]
    ];

    var isTypeScriptEnabled = validateBoolOption('ts', options.ts, false);
    if (isTypeScriptEnabled) {
        presets.push([require('@babel/preset-typescript').default]);
    }

    // ====================
    // plugins config
    var transformRuntimeOptions = (options && isObject(options['transform-runtime'])) ?
        assign({}, DEFAULT_TRANSFORM_RUNTIME_OPTIONS, options['transform-runtime']) :
        assign({}, DEFAULT_TRANSFORM_RUNTIME_OPTIONS);
    if (transformRuntimeOptions.absoluteRuntime) {
        transformRuntimeOptions.absoluteRuntime = path.dirname(
            require.resolve('@babel/runtime/package.json')
        );
    }

    var classPropertiesOptions = (options && isObject(options['class-properties'])) ?
        assign({}, options['class-properties']) :
        { loose: true };

    var privateMethodsOptions = (options && isObject(options['private-methods'])) ?
        assign({}, options['private-methods']) :
        { loose: true };

    var privatePropertyInObjectOptions = (options && isObject(options['private-property-in-object'])) ?
        assign({}, options['private-property-in-object']) :
        { loose: true };

    var plugins = [
        [require('@babel/plugin-proposal-class-properties').default, classPropertiesOptions],
        [require('@babel/plugin-proposal-private-methods').default, privateMethodsOptions],
        [require('@babel/plugin-proposal-private-property-in-object').default, privatePropertyInObjectOptions],
        [require('@babel/plugin-proposal-numeric-separator').default],
        [require('@babel/plugin-transform-runtime').default, transformRuntimeOptions]
    ];

    if (isTypeScriptEnabled) {
        plugins.unshift([require('@babel/plugin-proposal-decorators').default, false]);
    }

    if (isEnvProduction) {
        plugins.push([
            // Remove PropTypes from production build
            require('babel-plugin-transform-react-remove-prop-types').default,
            {
                removeImport: true
            }
        ]);
    }

    plugins.push(require('@babel/plugin-proposal-optional-chaining').default);
    plugins.push(require('@babel/plugin-proposal-nullish-coalescing-operator').default);

    // ====================
    // overrides config
    var overrides = [];
    if (isTypeScriptEnabled) {
        overrides.push({
            test: /\.tsx?$/,
            plugins: [
                [
                    require('@babel/plugin-proposal-decorators').default,
                    { legacy: true }
                ]
            ]
        });
    }

    return {
        presets: presets,
        plugins: plugins,
        overrides: overrides
    };
};