test: Use node.js test runner

[avaly]

I was interested to see how far we can get with replacing jest with the new native test runner in Node.js v20.

AFAICT The main blocker now is the fact that we can't mock ESM imports.

import * as model from '../model';
// ...

test('initialize with no models registered', (t) => {
  t.mock.method(model, 'build');

  const papr = new Papr();

  papr.initialize(db); // `model.build` inside the app code will not be mocked

  equal(model.build.mock.callCount(), 0);
});

The blocker regarding mocking modules was addressed in Node.js v22 with experimental support for module mocking.

I've rewritten all our tests using the native Node.js test runner & assert package.

[ejmartin504]

This is very interesting. Are we actually going to merge this? Given the "experimental" nature of it (and all the lint rules we have to disable), I don't see any reason to. What's your thinking?

[ejmartin504]

worth making an extra Mock utility type that does this for us? i.e. takes an object and re-types its properties as mocked versions?

[avaly]

This is very interesting. Are we actually going to merge this? Given the "experimental" nature of it (and all the lint rules we have to disable), I don't see any reason to. What's your thinking?

I am actually planning to merge this PR soon-ish TBH.

Given that the test runner feature is marked as Stable in node.js v22, we should be safe for the future. There will only be improvements in the future for this feature. It's a pretty decent feature IMHO, for a native feature baked into the language itself.

I agree that the experimental module mocking is the only part that is standing out. I'm fairly certain that it will improve & get to a stable point in the next node.js versions. Yes, the code to achieve module mocking looks weird, but to its defense, whatever jest has for supporting ESM modules & mocking would look very similar to what we had do here.

PS: The lint rules I disabled were mostly warnings about types. I'm hopeful that types will get improved soon for the module mocks.