next-intl/dist/esm/development/plugin/createMessagesDeclaration.js

Internationalization (i18n) for Next.js

import fs from 'fs';
import path from 'path';
import { throwError } from './utils.js';
import watchFile from './watchFile.js';

function runOnce(fn) {
  if (process.env._NEXT_INTL_COMPILE_MESSAGES === '1') {
    return;
  }
  process.env._NEXT_INTL_COMPILE_MESSAGES = '1';
  fn();
}
function createMessagesDeclaration(messagesPaths) {
  // Next.js can call the Next.js config multiple
  // times - ensure we only run once.
  runOnce(() => {
    for (const messagesPath of messagesPaths) {
      const fullPath = path.resolve(messagesPath);
      if (!fs.existsSync(fullPath)) {
        throwError(`\`createMessagesDeclaration\` points to a non-existent file: ${fullPath}`);
      }
      if (!fullPath.endsWith('.json')) {
        throwError(`\`createMessagesDeclaration\` needs to point to a JSON file. Received: ${fullPath}`);
      }

      // Keep this as a runtime check and don't replace
      // this with a constant during the build process
      const env = process.env['NODE_ENV'.trim()];
      compileDeclaration(messagesPath);
      if (env === 'development') {
        startWatching(messagesPath);
      }
    }
  });
}
function startWatching(messagesPath) {
  const watcher = watchFile(messagesPath, () => {
    compileDeclaration(messagesPath, true);
  });
  process.on('exit', () => {
    watcher.close();
  });
}
function compileDeclaration(messagesPath, async = false) {
  const declarationPath = messagesPath.replace(/\.json$/, '.d.json.ts');
  function createDeclaration(content) {
    return `// This file is auto-generated by next-intl, do not edit directly.
// See: https://next-intl.dev/docs/workflows/typescript#messages-arguments

declare const messages: ${content.trim()};
export default messages;`;
  }
  if (async) {
    return fs.promises.readFile(messagesPath, 'utf-8').then(content => fs.promises.writeFile(declarationPath, createDeclaration(content)));
  }
  const content = fs.readFileSync(messagesPath, 'utf-8');
  fs.writeFileSync(declarationPath, createDeclaration(content));
}

export { createMessagesDeclaration as default };