babel-plugin-transform-define

This Babel plugin will take a set of config values (or load them from a file path) and replace all occurrences in the parsed scripts. This plugin is compatible with Babel 7. Other Babel versions have not been tested.

npm i -D @oliver-schoendorn/babel-plugin-transform-define

Configuration example (.babelrc, static config)

{
    "plugins": [
        [ "@oliver-schoendorn/babel-plugin-transform-define", {
            "values": { "your": "values" } 
        } ]
    ]
}

Configuration example (.babelrc, config from file)

{
    "plugins": [
        [ "@oliver-schoendorn/babel-plugin-transform-define", {
            "file": "./src/config" 
        } ]
    ]
}

Examples

All of the following example will use these plugin config values:

{
  "values": {
    "process.env.NODE_ENV": "production",
    "isProduction": true,
    "CONFIG": {
      "API_HOST": "https://your.domain/"
    },
    "VAR": null,
    "TEST_STUFF": "/^foo$/igm",
    "didRTFM": true
  }
}

Variable declarations

Input

const initState = { initialized: true }
const appState = { global: { ...CONFIG, isProduction }, ...initialized }
const thisWorks = asWell = isProduction
const VAR = { CONFIG }

Output

const initState = { initialized: true }
const appState = { global: { ...{ "API_HOST": "https://your.domain" } }, ...initialized }
const thisWorks = asWell = true
const VAR = { CONFIG: { "API_HOST": "https://your.domain" } }

Assignments and calls

Input

const myObject = {}, isProduction = false
myObject.foo = VAR
myObject.isProduction = isProduction

new RegExp(TEST_STUFF)

Object.keys(CONFIG).map(key => console.log(key))

Output

const myObject = {}, isProduction = false
myObject.foo = null
myObject.isProduction = isProduction

new RegExp("/^foo$/igm")

Object.keys({ "API_HOST": "https://your.domain" }).map(key => console.log(key))

Exports

Input

export { CONFIG }
export default isProduction

Output

const CONFIG = { "API_HOST": "https://your.domain" }
export { CONFIG }

const isProduction = true
export default isProduction

Conditionals evaluation

Input

if (isProduction) { doThings() }
else { doSomthingElse() }

if (! isProduction) { whatEver() }
else { sorcery() }

const youAre = didRTFM ? 'awesome' : 'lazy'
const complicated = didRTFM && ! isProduction

const canNotEvaluate = didRTFM && require('./aScript')

Output

{ doThings() }
{ sorcery() }

const youAre = 'awesome'
const complicated = false
const canNotEvaluate = true && require('./aScript')

Options

Option key	Description	Type	Default value
values	Object with keys and values, that should be replaced. Please note that only the top level keys will be used for replacement. If you want to define process.env.NODE_ENV for instance, use { "process.env.NODE_ENV": "production" }	object	{}
file	Instead of passing an object, you can also reference a file. The given path has to be relative to your babel config and should use module.exports = { API_HOST: "https://..." }	string	undefined
memberExpressions	You can disable the processing of member expressions (node.env.NODE_ENV).	boolean	true
exportExpressions	Toggles the processing of export expressions (export { MY_CONFIG } or export default MY_CONFIG). Note: If you enable this option, you will have to set the babel parser option allowUndeclaredExports to true.	boolean	true
evaluateConditionals	Toggles the evaluation and simplification of If Statements, Unary Statements and so on.	boolean	true
verbose	If set to true, some information about the replaced nodes and their types will be printed to the console.	boolean	false