function $version(): string {
  'use macro';
  const { version } = require('../package.json');
  console.log(`Version: ${version}`);
  return version;
}
function $compiledAt(): Date {
  'use macro';
  return new Date();
}
async function $message(): Promise<string> {
  'use macro';
  const fs = require('fs').promises;
  const path = require('path');
  const messageText = path.resolve(__dirname, 'message.txt');
  const res = await fs.readFile(messageText, 'utf8');
  return res;
}
const $url = () => {
  'use macro';
  const url = new URL('https://example.com?foo=bar&baz=qux');
  return [url, url.searchParams];
};
const $formData = function () {
  'use macro';
  const formData = new FormData();
  formData.append('foo', 'bar');
  formData.append('baz', 'qux');
  return formData;
};
export const version = $version();
export const compiledAt = $compiledAt();
export const message = $message() as unknown as Awaited<ReturnType<typeof $message>>;
export const url = $url();
export const formData = $formData();

import { build } from 'esbuild';
import { esbuildPluginUseMacro } from 'use-macro';
build({
  entryPoints: ['src/index.ts'],
  bundle: true,
  outfile: 'dist/index.js',
  plugins: [esbuildPluginUseMacro()],
}).catch(() => process.exit(1));

import { MacroTransformer } from 'use-macro';
const transformer = new MacroTransformer();
const code = `
function $random(): number {
  'use macro';
  return Math.random();
}
`;
/**
 * The first argument is the code to transform.
 * The second argument is the file name, this is used to resolve relative imports.
 */
const result = transformer.transform(code, 'file.ts');
/*
{
  content: '...',
  loader: 'ts'
}
*/