To make some reusable codes, create and publish a npm package is a good idea.

Below I'll share base on my repo on github chinese-poker.

Init npm package

• create a directory mkdir your-package-name cd your-package-name
• make a initialization (-y means no prompt question and all question to be the defualt value)

npm init -y

Get a file tree like:

.
└── package.json

Write codes down:

below is my code files tree:

src
├── Config.ts
├── Const.ts
├── MetaProcessor.ts
├── Ruler.ts
├── SpecificGetFn.ts
├── __tests__
│   └── ruler_spec.ts
└── utils
    └── utils.ts

Intergrate code entry:

Make a file index.ts which we will assign it's path to the bundle config. Input the stuffs you want to export:

//index.ts
export {Ruler} from "./Ruler";
export {E_TYPE} from "./Config";

Bundle the codes:

It's nessary to make a bundle, for easy consuming. The bundle tool can resolve the module format like Commonjs and ESModule for different usage and help us transpile typescript file and generate d.ts file by some plugins.

Rollup, Webpack, and Parcel are all module bundler tools, but the focus is different. The Rollup we are going to talk about is more suitable for building Library, while Webpack and Precel are more suitable for developing Application

Here We choose Rollup because it's clean and easy to use.

Install rollup

npm i -D rollup

Create file rollup.config.js

import typescript from 'rollup-plugin-typescript2'; 
import babel from 'rollup-plugin-babel'; 
export default {
    input: 'src/index.ts',
    output: [
        {
            file: 'dist/index.esm.js',
            format: 'esm', 
            sourcemap: true
        }
    ],
    plugins: [typescript(),babel()]
}

• rollup-plugin-babel for compile typescript.
• rollup-plugin-typescript2 for generate d.ts file.
• set property input as your entry file.
• set property output to specify the output path and format.

Set types and module in package.json

//package.json
{
...
"types": "index.d.ts",
"module": "index.esm.js",
...
}

Run rollup

rollup -c

Then you can get the file tree like below:

dist
├── Config.d.ts
├── Const.d.ts
├── MetaProcessor.d.ts
├── README.md
├── Ruler.d.ts
├── SpecificGetFn.d.ts
├── __tests__
│   └── ruler_spec.d.ts
├── index.d.ts
├── index.esm.js
├── index.esm.js.map
└── utils
    └── utils.d.ts

Publish

• create a README.md file which is welcome for a easy describtion.
• copy README.md and package.json to dist.
• npm login(If you have't a npm account, get one npmjs)
• npm publish ./dist

Consuming the package:

npm install your-package-name

Use it just like other package you used to.

Thanks for your reading.

Have a good day.