define-messages

💬 define intl messages done right

Key features

This module is mainly started to fix some issues of react-intl's defineMessages, which usage is limited and not flexible enough. define-messages has almost all the features of defineMessages from react-intl but more.

• 📦 Babel plugin to extract the defined messages
• 🗑️ Babel plugin to completely remove the function call to enable dead-code elimination
• 💪 Flexible nested messages definition

Installation

yarn add define-messages

Usage

defineMessages function return the same thing as the passed in parameter and will do no effect in run-time. The magic is in the babel plugin.

import defineMessages from "define-messages";

// simple message
const message = defineMessages({
  id: "id",
  defaultMessage: "default message"
});

// multiple messages
const messages = defineMessages({
  title: {
    id: "title id",
    defaultMessage: "title default message"
  },
  description: {
    id: "description id",
    defaultMessage: "description default message"
  }
});

// even nested messages
const groupedMessages = defineMessages({
  animals: {
    cat: {
      id: "cat id",
      defaultMessage: "cat default message"
    }
  }
});

babel-plugin-transform-remove

// .babelrc

plugins: ["define-messages/babel/transform-remove"];

Enable it in client side and to completely remove the defineMessages() call in the build. It can enable uglifier like uglifyJS to perform dead-code elimination and remove the messages inside the function so that you won't accidentally bundle lots of messages you don't use into your build files.

babel-plugin-extract

// .babelrc

plugins: ["define-messages/babel/extract"];

Run it with babel transform will extract the defined messages into metadata of the transformed code. It's practically useful when you want to manually run the script to extract all the defined messages and generate a translation json file.

import { transform } from "@babel/core";

const code = `
  defineMessages({
    title: {
      id: "title id",
      defaultMessage: "title default message"
    },
    description: {
      id: "description id",
      defaultMessage: "description default message"
    }
  });
`;

const { metadata } = transform(code, {
  plugins: ["define-messages/babel/extract"]
});

console.log(metadata["define-messages"].messages);
// [
//   {
//     id: "title id",
//     defaultMessage: "title default message"
//   },
//   {
//     id: "description id",
//     defaultMessage: "description default message"
//   }
// ];

Migrate from react-intl

define-messages packaged a codemod to help you migrate from react-intl with a single command.

Run the command in your project root. All the recast and jscodeshift options are available.

npx jscodeshift -t node_modules/define-messages/codemod/react-intl-to-define-messages.js <path> [--quote=single] [--parser=flow]

Note that it currently only support es module import and the coding style of the transformed code is opinionated, feel free to transform it again with eslint --fix or prettier --write.

Author

Kai Hao

License

MIT