adds mocha polyfill to clear it.each errors

[dimitropoulos]

Wherever it.each is called, but only in insomnia-inso and insomnia-app, we see the following error:

if you dig in, you'll see that this is due to these projects importing insomnia-testing which uses the Mocha types. What's shown here is that TypeScript is getting the types from two places for the same global definition for it (look at the pane on the right):

so now, going back to each, if you hover over the error it tells you where there's a problem:

Jest defines:

declare var it: jest.It;

while Mocha defines:

declare var it: Mocha.TestFunction;

So we know it's from Mocha because the error complained about TestFunction. Another way we know is you can just look at the jest.It definition, and sure enough, you'll see that each is defined.

The problem, then, is that mocha's TestFunction is missing each and since they're both merged global definitions, that isn't something TypeScript will allow. The thing is, though... we're not using Mocha. There's no way to tell TypeScript this since they're both globals.

Other people seemed to solve this by making it a dev dependency (cypress-io/cypress#6690 (comment), soundcloud/intervene#3) but it already is for us, and, anyway, our situation is different because we actually need to consume and re-export these types from insomnia-testing so this wouldn't solve our issue.

This isn't a problem for other packages in the project, e.g. o2k (see generate.test.ts) which do not import insomnia-testing.

Therefore, I've opted to solve this by adding a fake ambient definition for Mocha.TestFunction['each']. This makes the errors go away and I don't think there's any real risk to us because we're not actually using mocha.

---

That said, I'll mention @reynolek that the long-term fix for us (in my non-product-person non-decision-making opinion) is to remove mocha from all projects and just use jest and jest-runner for insomnia-testing. There are many other reasons to do this, but this hack we have to now impose is just another one to add to the pile.

[develohpanda]

Gosh this is unfortunate, nice find.

Let's say at some future point in time we drop mocha and use jest-runner in insomnia-testing - could we bump into a similar conflict? I would hope not because I'd hope jest-runner is purely just that, a runner

[dimitropoulos]

Nope, the conflict would be gone because the mocha types would be nowhere to be found in our project.