babel-plugin-transform-define

Compile time code replacement for babel similar to Webpack's DefinePlugin

Quick Start

$ npm install --save-dev babel-plugin-transform-define

.babelrc

{
  "plugins": [
    ["transform-define", {
      "process.env.NODE_ENV": "production",
      "typeof window": "object"
    }]
  ]
}

.babelrc.js

// E.g., any dynamic logic with JS, environment variables, etc.
const overrides = require("./another-path.js");

module.exports = {
  plugins: [
    ["transform-define", {
      "process.env.NODE_ENV": "production",
      "typeof window": "object",
      ...overrides
    }]
  ]
};

Reference Documentation

babel-plugin-transform-define can transform certain types of code as a babel transformation.

Identifiers

.babelrc

{
  "plugins": [
    ["transform-define", {
      "VERSION": "1.0.0",
    }]
  ]
}

Source Code

VERSION;

window.__MY_COMPANY__ = {
  version: VERSION
};

Output Code

"1.0.0";

window.__MY_COMPANY__ = {
  version: "1.0.0"
};

Member Expressions

.babelrc

{
  "plugins": [
    ["transform-define", {
      "process.env.NODE_ENV": "production"
    }]
  ]
}

Source Code

if (process.env.NODE_ENV === "production") {
  console.log(true);
}

Output Code

if (true) {
  console.log(true);
}

Unary Expressions

.babelrc

{
  "plugins": [
    ["transform-define", {
      "typeof window": "object"
    }]
  ]
}

Source Code

typeof window;
typeof window === "object";

Output Code

'object';
true;

License

MIT License