🛠️ Repo: Convert `cli.js` to ESM

[mark-wiemer]

Tooling Suggestion Checklist

• I have tried restarting my IDE and the issue persists.
• I have pulled the latest main branch of the repository.
• I have read and agree to Mocha's Code of Conduct and Contributing Guidelines
• I have searched for related issues and issues with the faq label, but none matched my issue.
• I want to provide a PR to resolve this

Overview

This file has some funky code that we need to be extra careful about, let's convert it in its own PR

Additional Info

Let's also do this one early so we can add it to a beta earlier.

[mark-wiemer]

I had three main concerns:

---

Special require() logic:

  // ensure we can require() from current working directory
  if (typeof module.paths !== "undefined") {
    module.paths.push(cwd(), path.resolve("node_modules"));
  }

I'm still not quite sure what this does.

---

Allow direct execution:

// allow direct execution
if (require.main === module) {
  exports.main();
}

I think we can handle this with argv stuff :)

---

bin/_mocha logic:

/**
 * This file remains for backwards compatibility only.
 * Don't put stuff in this file.
 * @see module:lib/cli
 */

require("../lib/cli").main();

This imports lib/cli/index.js, so we're good :)

---

PS I'm still recovering from my concussion so please excuse the lack of deep research here 🫣