search

mochajs / mocha

☕️ simple, flexible, fun javascript test framework for node.js & the browser
https://mochajs.org
MIT License
22.64k stars 3.02k forks source link

🚀 Feature: Add support for additional runtimes like Bun and Deno #5108

Open voxpelli opened 9 months ago

voxpelli commented 9 months ago

Feature Request Checklist

Overview

As mentioned in https://github.com/mochajs/mocha/issues/5065#issuecomment-1967346075, https://github.com/wintercg/proposal-common-minimum-api/issues/68 and https://twitter.com/_nicojs/status/1762508703863894472:

Nicholas C. Zakas @slicknet What I want: To write JavaScript tests once and be able to run them across Node.js, Bun, and Deno. Problem: Bun and Deno have built-in test runners you have to import from to run tests. I use Mocha. This doesn't work. Solution: ???

There is a need for a cross-runtime testing library.

Mocha already supports browsers and node.js, what would it take to support eg. Deno and Bun as well?

Suggested Solution

Research what would be needed to support Bun and Deno and evaluate the feasibility.

Alternatives

Standardizing on a shared built in test API and move away from Mocha: https://github.com/wintercg/proposal-common-minimum-api/issues/68

This would only solve it for those runtimes who are compliant with the WinterCG proposal though and not work for eg browsers. It also would mean running the tests in multiple different implementations of the same test framework, which can have unexpected consequences.

Additional Info

No response

nzakas commented 9 months ago

One thing I noticed when running Mocha on Bun: When there is a test failure, Mocha's exit code is 0, making it appear that CI is passing if you don't look at the console output.

JoshuaKGoldberg commented 1 month ago

👍 we've been chatting about this off-and-on for most of this year. We're generally in favor.

I think in order for this to happen, we'd need to roll out slowly. Here's a strategy proposal:

  1. Add examples for Bun and Deno to https://github.com/mochajs/mocha-examples
  2. Add executing tests for Bun and Deno to Mocha's CI
    • Since these will probably be failing at first, perhaps just for the main branch & on PRs with a particular label?
  3. See what CI run failures arise from that, and file standalone issues
  4. For each of Bun and Deno, once they have no CI failures, announce them as experimentally available in production
  5. Wait some time to gather user input
  6. Announce them as officially supported in production

This is lower priority than work on Mocha 11 (https://github.com/mochajs/mocha/milestone/65) or 12 (https://github.com/mochajs/mocha/milestone/66), but would be great down the road.