If you look at the import.meta docs on MDN you'll notice that it says:
The spec doesn't specify any properties to be defined on it, but hosts usually implement the following properties: [url, resolve]
So what is actually in there? MDN is correct in saying url and resolve are usually (always) implemented, but each run-time also sticks some other stuff in there. From my own testing, below are the values that exist for each major runtime.
Node.js now has a built-in test runner, which I've now tried, and it's fantastic! However, it can't be used for frontend testing, or browser testing, obviously. While web-test-runner is the best (imo) test runner for frontend tests, having different runners requires you to learn different libraries and use different imports for each even when doing dead simple environment-agnostic unit tests. In this post I'll talk about how I've unified the experience, and the path that lead to being able to do that.
ESM does not populate the __filename and __dirname variables frequently used in CommonJS. This post shows what to do instead.