Why don't production and developmeent modes work?

Question

webpack

When I set the webpack work mode to "production" or "developmeent", I see the following error:
Here is my webpack.config.js file:

const NODE_ENV = process.env.NODE_ENV || 'development';
const webpack = require('webpack');

module.exports = {
    entry: "./src",
        output: {
            filename: "build.js",
            library: "src"
        },
        watch: NODE_ENV == 'development',

        watchOptions: {
        aggregateTimeout: 200
        },

        devtool: NODE_ENV == 'development' ? "cheap-inline-module-source-map" : null,

    plugins: [
        new webpack.DefinePlugin({
            NODE_ENV: JSON.stringify(NODE_ENV)
        })
    ],

    resolve: {
        modules: ["node_modules"],
        extensions: ["*", ".js"]
    },

    resolveLoader: {
        modules: ["node_modules"],
        moduleExtensions: ['-loader'],
        extensions: ["*", ".js"]
    },

    module: {
        rules: [
            {
                test: /\.js$/,
                exclude: /(node_modules|bower_components)/,
                use: {
                    loader: 'babel-loader'
                }
        }

        ]
    }

    };


if(NODE_ENV == 'production') {
    const UglifyJsPlugin = require('uglifyjs-webpack-plugin');

    module.exports = {
        optimization: {
            minimizer: [
                // we specify a custom UglifyJsPlugin here to get source maps in production
                new UglifyJsPlugin({
                    cache: true,
                    parallel: true,
                    uglifyOptions: {
                        compress: false,
                        ecma: 6,
                        mangle: true
                    },
                    sourceMap: true
                })
            ]
        }
    };
}

Answer 1

It says in plain text that the devtool key must be string or false . At you in a production mode on a condition null
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