https://github.com/jonnyburger/xns

Make the default export of a file executable in in Node.js!
https://github.com/jonnyburger/xns

cli helper node

Last synced: 2 months ago
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Make the default export of a file executable in in Node.js!

• Host: GitHub
• URL: https://github.com/jonnyburger/xns
• Owner: JonnyBurger
• Created: 2018-11-07T18:26:47.000Z (about 6 years ago)
• Default Branch: master
• Last Pushed: 2020-01-07T20:04:27.000Z (about 5 years ago)
• Last Synced: 2024-10-26T22:24:52.936Z (3 months ago)
• Topics: cli, helper, node
• Language: TypeScript
• Homepage: https://www.npmjs.com/package/xns
• Size: 8.79 KB
• Stars: 6
• Watchers: 3
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md

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README

        
# xns

> Turn any function into a script that can be invoked from the command line.

xns stands for e**X**ecute **N**ode **S**cript!  

## Problem

Let's say you have written a cool JavaScript (or TypeScript) function!

`get-bitcoin-price.ts`:

```js

import got from 'got';

export default async (): Promise => {

  const res = await got('https://api.coinbase.com/v2/prices/spot');

  const {currency, amount} = JSON.parse(res.body).data;

  return `1 Bitcoin is worth ${currency} ${amount}`;

};

```

Now you would like to execute this function in your terminal.

Current options are not ideal:

- You could make the function self-invoking, but then it also executes by itself as soon as it's imported somewhere else.

- You could make another file, import the function and execute it, then run that file, but it's cumbersome.

## Solution

Wrap your function in `xns()`:

`get-bitcoin-price.ts`:

```js

import xns from 'xns';

import got from 'got';

export default xns(async (): Promise => {

  const res = await got('https://api.coinbase.com/v2/prices/spot');

  const {currency, amount} = JSON.parse(res.body).data;

  return `1 Bitcoin is worth ${currency} ${amount}`;

});

```

Now you can execute the function from your terminal:

```sh

ts-node get-bitcoin-price

1 Bitcoin is worth USD 7767.655

```

You can also still import the function from somewhere else as usual and it will not execute itself 👌

## Why `xns`?

- Works with `node` and transpiled languages: `ts-node`, `babel-node`...

- Can still be imported as normal

- Prints out the return value

- Fully typed, keep Typescript typings

- Wrapping function in xns does not change behavior of your app

- Exit code 1 on error, exit code 0 on success, perfect for CRON jobs

- No `Unhandled promise rejection` errors, proper catch handler built in

- Works with synchronous and asynchronous functions

- Works with ES Modules and CommonJS import style

    - Use named export for CommonJS: `const {xns} = require('xns')`

## Old version of `xns`

This is version 2 of `xns`. Version 1 worked completely different, it compiled a file using babel and called the default export. It's still supported if you have Babel. See [here](https://github.com/JonnyBurger/xns/tree/e91cd60e16990e43bfb37aa76c6e382f64b4e9da) for the old API.

## License

MIT

## Author

[Jonny Burger](jonny.io)