NPM Packages with TypeScript

The more I play with the programming, the more I realize that I am often rewriting the same code. I therefore decided to upload some functions to NPM. But how can I create an NPM package using TypeScript? Well, I had to put together a few guides and do some tests. These are the steps I followed.

Initialize the package and install TypeScript

I create the package.json file with default values:

npm init -y

Then I add the node_modules folder among the paths to ignore in .gitignore.

I install TypeScript:

npm install --save-dev typescript

I configure the tsconfig.json file:

{
    "compilerOptions": {
        "outDir": "./lib",
        "module": "ES2020", // or commonjs
        "target": "ES2019",
        "lib": [
            "ES2019",
            "DOM",
            "ES2020"
        ],
        "declaration": true,
        "strict": true
    },
    "include": ["src"],
    "exclude": ["node_modules", "**/__tests__/*"]
}

I create a src folder in which to put the starting code. Then I add the index.ts file:

const myCustomFunction = (name: string):string => `Hello ${name}`;
function ciao(name: string): string {
    return `Ciao ${name}`;
}

export {…