Error

vue2.0 error:Syntax Error: TypeError: eslint.CLIEngine is not a constructor

Solution

Change your confit  to the following code in vue.config.js.
module.exports = {
    devServer: {
        overlay: {
            warnings: true,
            errors: true
        }
    },
    lintOnSave: 'error',
    chainWebpack: config => {
        config.module.rule('eslint').use('eslint-loader').loader('eslint-loader').tap(opt => {
            opt.emitWarning = opt.emitError = opt.failOnWarning = opt.failOnError = true;
            return opt;
        });
    }
};