Suggestion: an integration with esbuild to replace `ts-node/register` and `@babel/register`

Since one of the main aim of uvu is fast, use esbuild to replace babel or tsc would make unit tests with uvu much faster for end users.

[eyelidlessness]

Just want to report that I was able to get this working fairly painlessly with Estrella, like so:

// ./scripts/test.js
// @ts-check

import del      from 'del';
import estrella from 'estrella';
import globby   from 'globby';
import path     from 'path';

(async () => {
  const cwd = process.cwd();

  const [ , args ] = estrella.cliopts.parse();
  const [ testDirName = 'test' ] = args;
  const entry = await globby(path.resolve(cwd, testDirName, '**/*.test.ts'));
  const outDir = path.resolve(cwd, './.test');

  estrella.build({
    cwd,
    entry,
    minify:    false,
    outdir:    outDir,
    run:       `npx uvu ${JSON.stringify(outDir)}`,
    sourcemap: 'inline',

    async onStart() {
      await del(outDir);
    },
  });
})();

Usage:

node ./scripts/test.js

Watch:

node ./scripts/test.js -w

Easy peasy! Obviously, any of the details of this may be changed. It does write to the filesystem, so if that’s something you’re really trying to avoid you’ll want something like esbuild-register or ts-eager. But wanted to share my solution in case it helps.

[osdevisnot]

It seems esbuild-register works ok, at least with minimal examples I tried it with. Made an example PR in #119.