Global jest type from test-utils causing issues when existing test files also interact with the global jest object

[philwolstenholme]

Hi, thanks for your work on this package :)

I just used patch-package to patch react-intersection-observer@9.14.0 for the project I'm working on. I don't think this is the best fix, but it resolved an issue I'd been having.

In some of our existing test files we have to do a little trick like this:

// https://github.com/testing-library/react-testing-library/issues/1197#issuecomment-1693824628
// @ts-expect-error type hoohaa
globalThis.jest = {
  advanceTimersByTime: vi.advanceTimersByTime.bind(vi)
};

You can check out the RTL issue link for more context of why we have to do this. There may be a better way, but this has worked for our project for almost a year without any issues.

I added react-intersection-observer to our project today and used react-intersection-observer/test-utils. We then started getting TypeScript errors like these:

src/app/(shopfront)/(simplified)/checkout/payment/complete/CompletePage.test.tsx:71:5 - error TS2353: Object literal may only specify known properties, and 'advanceTimersByTime' does not exist in type '{ fn: <T extends Procedure = Procedure>(implementation?: T | undefined) => Mock<T>; }'.

71     advanceTimersByTime: vi.advanceTimersByTime.bind(vi)
       ~~~~~~~~~~~~~~~~~~~

The global jest type from react-intersection-observer/test-utils was affecting our test files and resulting in errors.

I was wondering if the type from react-intersection-observer/test-utils needs to be global? If that type is just for your own development needs then a module-scope type might be better, I think?

---

Here is the diff that solved my problem:

diff --git a/node_modules/react-intersection-observer/test-utils/index.d.mts b/node_modules/react-intersection-observer/test-utils/index.d.mts
index 58a5d85..464972a 100644
--- a/node_modules/react-intersection-observer/test-utils/index.d.mts
+++ b/node_modules/react-intersection-observer/test-utils/index.d.mts
@@ -1,9 +1,3 @@
-declare global {
-    var IS_REACT_ACT_ENVIRONMENT: boolean;
-    var jest: {
-        fn: typeof vi.fn;
-    } | undefined;
-}
 /**
  * Create a custom IntersectionObserver mock, allowing us to intercept the `observe` and `unobserve` calls.
  * We keep track of the elements being observed, so when `mockAllIsIntersecting` is triggered it will
diff --git a/node_modules/react-intersection-observer/test-utils/index.d.ts b/node_modules/react-intersection-observer/test-utils/index.d.ts
index 58a5d85..464972a 100644
--- a/node_modules/react-intersection-observer/test-utils/index.d.ts
+++ b/node_modules/react-intersection-observer/test-utils/index.d.ts
@@ -1,9 +1,3 @@
-declare global {
-    var IS_REACT_ACT_ENVIRONMENT: boolean;
-    var jest: {
-        fn: typeof vi.fn;
-    } | undefined;
-}
 /**
  * Create a custom IntersectionObserver mock, allowing us to intercept the `observe` and `unobserve` calls.
  * We keep track of the elements being observed, so when `mockAllIsIntersecting` is triggered it will

This issue body was partially generated by patch-package.

[thebuilder]

This makes sense - I guess we might just have ignore types jest, so we don't get it mixed up. The variables are set globally by Jest/Testing Library. Not sure if there's another way of defining global variables scoped to a module?

[thebuilder]

🎉 This issue has been resolved in version 9.14.1 🎉

The release is available on:

• npm package (@latest dist-tag)
• GitHub release

Your semantic-release bot 📦🚀

[philwolstenholme]

Thanks for the new releaese @thebuilder, it solves both my issues!