TypeError：messages.greetings不是函数

Question

我试图导入使用Webpack编译的TypeScript模块，但是出现以下错误，

TypeError: messages.sayHello is not a function
at Object.<anonymous> (/Users/gaurangdave/workspace/experiments/tmp/ts_modules/main.js:3:22)
at Module._compile (module.js:652:30)
at Object.Module._extensions..js (module.js:663:10)
at Module.load (module.js:565:32)
at tryModuleLoad (module.js:505:12)
at Function.Module._load (module.js:497:3)
at Function.Module.runMain (module.js:693:10)
at startup (bootstrap_node.js:191:16)
at bootstrap_node.js:612:3

下面是TypeScript，

const sayHello = name => {
  console.log(`Hello ${name}`);
};

export default { sayHello };

下面是Webpack配置

const path = require('path');
const webpack = require('webpack');

module.exports = {
     mode: 'none',
     entry: {
          greetings: './greetings.ts',
     },
     target: 'node',
     resolve: {
          extensions: ['.ts', '.js']
     },
     optimization: {
          minimize: false
     },
     output: {
          // Puts the output at the root of the dist folder
          path: path.join(__dirname, 'dist'),
          filename: '[name].js'
     },
     module: {
          rules: [{
               test: /\.ts$/,
               loader: 'ts-loader'
          }]
     },
     plugins: []
}

有点受阻，有人可以丢点光吗？

谢谢 高朗

编辑：

我正在按如下方式调用sayHello函数

const greetings = require('./dist/greetings');

greetings.sayHello();