Invalid configuration object. Webpack has been initialised using a configuration object that does not match the API schema.

 - configuration.module has an unknown property 'exclude'. These properties are valid:

   object { exprContextCritical?, exprContextRecursive?, exprContextRegExp?, exprContextRequest?, noParse?, rules?, defaultRules?, unknownContextCritical?, unknownContextRecursive?, unknownContextRegExp?, unknownContextRequest?, unsafeCache?, wrappedContextCritical?, wrappedContextRecursive?, wrappedContextRegExp?, strictExportPresence?, strictThisContextOnImports? }

   -> Options affecting the normal modules (`NormalModuleFactory`).

webpack.config.js

module.exports = {
    entry: {
        app: './app.js'
    },
    output: {
        filename: '[name].[hash:8].js'
    },
    module: {
        rules: [
            {
                test: /\.js$/,
                exclude: '/node_modules/',
                use: {
                    loader: 'babel-loader'
                }
            }
        ]
    }