docs(TestingAsyncCode.md): add note about not mixing done w/promises (#…

…11077)

CHANGELOG.md

@@ -44,6 +44,7 @@
 - `[jest-snapshot]` [**BREAKING**] Migrate to ESM ([#12342](https://github.com/facebook/jest/pull/12342))
 - `[jest-transform]` Update `write-file-atomic` to v4 ([#12357](https://github.com/facebook/jest/pull/12357))
 - `[jest]` Use `index.ts` instead of `jest.ts` as main export ([#12329](https://github.com/facebook/jest/pull/12329))
+- `[docs]` Add note about not mixing `done()` with Promises ([#11077](https://github.com/facebook/jest/pull/11077))
 
 ### Performance
 

docs/TestingAsyncCode.md

@@ -47,6 +47,8 @@ If `done()` is never called, the test will fail (with timeout error), which is w
 
 If the `expect` statement fails, it throws an error and `done()` is not called. If we want to see in the test log why it failed, we have to wrap `expect` in a `try` block and pass the error in the `catch` block to `done`. Otherwise, we end up with an opaque timeout error that doesn't show what value was received by `expect(data)`.
 
+_Note: `done()` should not be mixed with Promises as this tends to lead to memory leaks in your tests._
+
 ## Promises
 
 If your code uses promises, there is a more straightforward way to handle asynchronous tests. Return a promise from your test, and Jest will wait for that promise to resolve. If the promise is rejected, the test will automatically fail.

website/versioned_docs/version-25.x/TestingAsyncCode.md

@@ -47,6 +47,8 @@ If `done()` is never called, the test will fail (with timeout error), which is w
 
 If the `expect` statement fails, it throws an error and `done()` is not called. If we want to see in the test log why it failed, we have to wrap `expect` in a `try` block and pass the error in the `catch` block to `done`. Otherwise, we end up with an opaque timeout error that doesn't show what value was received by `expect(data)`.
 
+_Note: `done()` should not be mixed with Promises as this tends to lead to memory leaks in your tests._
+
 ## Promises
 
 If your code uses promises, there is a more straightforward way to handle asynchronous tests. Return a promise from your test, and Jest will wait for that promise to resolve. If the promise is rejected, the test will automatically fail.

website/versioned_docs/version-26.x/TestingAsyncCode.md

@@ -47,6 +47,8 @@ If `done()` is never called, the test will fail (with timeout error), which is w
 
 If the `expect` statement fails, it throws an error and `done()` is not called. If we want to see in the test log why it failed, we have to wrap `expect` in a `try` block and pass the error in the `catch` block to `done`. Otherwise, we end up with an opaque timeout error that doesn't show what value was received by `expect(data)`.
 
+_Note: `done()` should not be mixed with Promises as this tends to lead to memory leaks in your tests._
+
 ## Promises
 
 If your code uses promises, there is a more straightforward way to handle asynchronous tests. Return a promise from your test, and Jest will wait for that promise to resolve. If the promise is rejected, the test will automatically fail.

website/versioned_docs/version-27.0/TestingAsyncCode.md

@@ -47,6 +47,8 @@ If `done()` is never called, the test will fail (with timeout error), which is w
 
 If the `expect` statement fails, it throws an error and `done()` is not called. If we want to see in the test log why it failed, we have to wrap `expect` in a `try` block and pass the error in the `catch` block to `done`. Otherwise, we end up with an opaque timeout error that doesn't show what value was received by `expect(data)`.
 
+_Note: `done()` should not be mixed with Promises as this tends to lead to memory leaks in your tests._
+
 ## Promises
 
 If your code uses promises, there is a more straightforward way to handle asynchronous tests. Return a promise from your test, and Jest will wait for that promise to resolve. If the promise is rejected, the test will automatically fail.

website/versioned_docs/version-27.1/TestingAsyncCode.md

@@ -47,6 +47,8 @@ If `done()` is never called, the test will fail (with timeout error), which is w
 
 If the `expect` statement fails, it throws an error and `done()` is not called. If we want to see in the test log why it failed, we have to wrap `expect` in a `try` block and pass the error in the `catch` block to `done`. Otherwise, we end up with an opaque timeout error that doesn't show what value was received by `expect(data)`.
 
+_Note: `done()` should not be mixed with Promises as this tends to lead to memory leaks in your tests._
+
 ## Promises
 
 If your code uses promises, there is a more straightforward way to handle asynchronous tests. Return a promise from your test, and Jest will wait for that promise to resolve. If the promise is rejected, the test will automatically fail.

website/versioned_docs/version-27.2/TestingAsyncCode.md

@@ -47,6 +47,8 @@ If `done()` is never called, the test will fail (with timeout error), which is w
 
 If the `expect` statement fails, it throws an error and `done()` is not called. If we want to see in the test log why it failed, we have to wrap `expect` in a `try` block and pass the error in the `catch` block to `done`. Otherwise, we end up with an opaque timeout error that doesn't show what value was received by `expect(data)`.
 
+_Note: `done()` should not be mixed with Promises as this tends to lead to memory leaks in your tests._
+
 ## Promises
 
 If your code uses promises, there is a more straightforward way to handle asynchronous tests. Return a promise from your test, and Jest will wait for that promise to resolve. If the promise is rejected, the test will automatically fail.

website/versioned_docs/version-27.4/TestingAsyncCode.md

@@ -47,6 +47,8 @@ If `done()` is never called, the test will fail (with timeout error), which is w
 
 If the `expect` statement fails, it throws an error and `done()` is not called. If we want to see in the test log why it failed, we have to wrap `expect` in a `try` block and pass the error in the `catch` block to `done`. Otherwise, we end up with an opaque timeout error that doesn't show what value was received by `expect(data)`.
 
+_Note: `done()` should not be mixed with Promises as this tends to lead to memory leaks in your tests._
+
 ## Promises
 
 If your code uses promises, there is a more straightforward way to handle asynchronous tests. Return a promise from your test, and Jest will wait for that promise to resolve. If the promise is rejected, the test will automatically fail.

website/versioned_docs/version-27.5/TestingAsyncCode.md

@@ -47,6 +47,8 @@ If `done()` is never called, the test will fail (with timeout error), which is w
 
 If the `expect` statement fails, it throws an error and `done()` is not called. If we want to see in the test log why it failed, we have to wrap `expect` in a `try` block and pass the error in the `catch` block to `done`. Otherwise, we end up with an opaque timeout error that doesn't show what value was received by `expect(data)`.
 
+_Note: `done()` should not be mixed with Promises as this tends to lead to memory leaks in your tests._
+
 ## Promises
 
 If your code uses promises, there is a more straightforward way to handle asynchronous tests. Return a promise from your test, and Jest will wait for that promise to resolve. If the promise is rejected, the test will automatically fail.