webpackでtypescriptをjavascriptに変換

準備

$ yarn init -y
$ yarn add -D webpack webpack-cli
$ yarn add -D typescript ts-loader

index.tsを用意

src/index.ts

let a : number = 0

console.log(a)

tsconfig.jsonを作成

$ npx tsc --init

webpack.config.jsでts-loader適用する

webpack.config.js

module.exports = {
    entry: path.resolve(__dirname, 'src', 'index.ts'),
    output: {
        path: path.resolve(__dirname, 'dist'),
        filename: 'main.js',
    },
    module: {
        rules: [
            {
                test: /\.ts$/,
                use: 'ts-loader',
            }
        ],
    },
    resolve: {
        extensions: [ '.ts', '.js'],
    },
}

ビルド

$ npx webpack

結果

dist/main.js

(()=>{"use strict";console.log(0)})();