Load local JSON file into variable

My solution, as answered here, is to use:

    var json = require('./data.json'); //with path

The file is loaded only once, further requests use cache.

edit To avoid caching, here's the helper function from this blogpost given in the comments, using the fs module:

var readJson = (path, cb) => {
  fs.readFile(require.resolve(path), (err, data) => {
    if (err)
      cb(err)
    else
      cb(null, JSON.parse(data))
  })
}

For ES6/ES2015 you can import directly like:

// example.json
{
    "name": "testing"
}


// ES6/ES2015
// app.js
import * as data from './example.json';
const {name} = data;
console.log(name); // output 'testing'

If you use Typescript, you may declare json module like:

// tying.d.ts
declare module "*.json" {
    const value: any;
    export default value;
}

Since Typescript 2.9+ you can add --resolveJsonModule compilerOptions in tsconfig.json

{
  "compilerOptions": {
    "target": "es5",
     ...
    "resolveJsonModule": true,
     ...
  },
  ...
}