feat: add warnings when globals are missing (#1244)

* feat: add warnings when globals are missing

* revert the istanbul ignore removal

* improve error message

* Apply suggestions from code review

Co-authored-by: Tim Deschryver <28659384+timdeschryver@users.noreply.github.com>

---------

Co-authored-by: Tim Deschryver <28659384+timdeschryver@users.noreply.github.com>

Author: MatanBobi

src/index.js

@@ -20,6 +20,10 @@ if (typeof process === 'undefined' || !process.env?.RTL_SKIP_AUTO_CLEANUP) {
     teardown(() => {
       cleanup()
     })
+  } else {
+    console.warn(
+      `The current test runner does not support afterEach/teardown hooks. This means we won't be able to run automatic cleanup and you should be calling cleanup() manually.`,
+    )
   }
 
   // No test setup with other test runners available
@@ -35,6 +39,10 @@ if (typeof process === 'undefined' || !process.env?.RTL_SKIP_AUTO_CLEANUP) {
     afterAll(() => {
       setReactActEnvironment(previousIsReactActEnvironment)
     })
+  } else {
+    console.warn(
+      'The current test runner does not support beforeAll/afterAll hooks. This means you should be setting IS_REACT_ACT_ENVIRONMENT manually.',
+    )
   }
 }