@braw/rollup-plugin-icu-messages v1.0.0-alpha.1

rollup-plugin-icu-messages

Transform files containing ICU MessageFormat messages.

Summary

This Rollup plugin adds a transform hook that pre-parses all messages in the JSON file into an AST that can be used at runtime without the need to bring in a parser, allowing the bundle size to be reduced. Read more about how this works on the Format.JS website →

Installation

With package manager of your choice:

npm

npm i -D @braw/rollup-plugin-icu-messages

yarn

yarn add -D @braw/rollup-plugin-icu-messages

pnpm

pnpm i -D @braw/rollup-plugin-icu-messages

Usage

In your Rollup file, import the default export from the @braw/rollup-plugin-icu-messages and then use it as a function in your plugins config array.

Example configuration:

import { defineConfig } from 'rollup'
import { icuMessages } from '@braw/rollup-plugin-icu-messages'

export default defineConfig({
  input: './src/index.mjs',
  output: { dir: './dist' },
  plugins: [
    icuMessages({
      include: './i18n/*.json',
      format: 'crowdin',
    }),
  ],
})

The following options are supported:

• include (optional, default: '**/*.messages.json') — either a single glob string or regular expression, or an array of them, which must match the file IDs to be included in the transformation.
• exclude (optional, default: undefined) — either a single glob string or regular expression, or an array of them, which must match the file IDs to be excluded from the transformation.
• indent (optional, default: '\t') — string or a number of spaces used for indentation.
• parse (optional, default: (code) => JSON.parse(code)) — a function that takes the file content and ID, parses it and returns the JS object to pass to the format function.
• format (optional, default: default) — either a string with the name of the built-in formatter, or a function that accepts parsed file contents (using the parse function) and produces a record of messages, keyed by their IDs. For a list of built-in formatters, see the @formatjs/cli documentation →.
• parserOptions (optional, default: undefined) — an object whose keys are message IDs and whose values are either parsing options for those messages or a function that generates parsing options based on contextual information (such as module ID, message ID, and all messages).

Usage with other JSON plugins

Your configuration may already include a plugin that handles JSON or other files that may conflict with this plugin.

You can configure this plugin to include files with other extensions and store your messages in, e.g. .messages files. Just change options.include to **/*.messages in this case.

Alternatively you can use a separate plugin in this package — icuMessagesWrapPlugins, exported from @braw/rollup-plugin-icu-messages/wrap-plugins.

import { defineConfig } from 'rollup'
import json from '@rollup/plugin-json'
import { icuMessages } from '@braw/rollup-plugin-icu-messages'
import { icuMessagesWrapPlugins } from '@braw/rollup-plugin-icu-messages/wrap-plugins'

export default defineConfig({
  input: './src/index.mjs',
  output: { dir: './dist' },
  plugins: [
    json(),
    icuMessages({
      include: './i18n/*.json',
      format: 'crowdin',
    }),
    icuMessagesWrapPlugins({
      extendDefaults: true,
      wrappers: {
        'my-plugin'(plugin, filter) {
          // implement plugin wrapping here
          // use filter to check if the file is handled by icuMessages plugin
        },
      },
    }),
  ],
})