'request' cannot be tree-shaken out of a webpack bundle

[jgravois]

git checkout doc/webpack && npm i && npx webpack 🤔

https://webpack.js.org/guides/tree-shaking/

src/index.js

import { requiresFormData } from "@esri/arcgis-rest-request";

let element = document.createElement('div');
document.body.appendChild(element);

const options = {
  params: {
    baz: "bar"
  }
}

element.innerHTML = requiresFormData(options); // false

package.json

{
  "name": "@esri/arcgis-rest-webpack-demo",
  "version": "1.0.0",
  "private": true,
  "description": "",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1",
    "build": "webpack"
  },
  "keywords": [],
  "author": "",
  "license": "ISC",
  "devDependencies": {
    "webpack": "^4.28.2",
    "webpack-cli": "^3.1.2"
  },
  "dependencies": {
    "@esri/arcgis-rest-request": "^1.14.3"
  },
  "sideEffects": false
}

webpack.config.js

const path = require('path');

module.exports = {
  entry: './src/index.js',
  output: {
    filename: 'bundle.js',
    path: path.resolve(__dirname, 'dist')
  },
  mode: 'development',
  optimization: {
    usedExports: true
  }
};

[jgravois]

a demo that shows webpack tree shaking in action can now be found in the repo

https://github.com/Esri/arcgis-rest-js/tree/master/demos/tree-shaking

disclaimer: there are still some gotcha's here related to the fact that our compilation target is es5 and we include tslib as a dependency.

that said, we'd love to hear from users to try and make additional improvements.