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Sep 10, 2019
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Add FAQ about "update not wrapped in act" warnings #255

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Add FAQ about "update not wrapped in act" warnings
grncdr Sep 10, 2019
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Update faq.md
grncdr Sep 10, 2019
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Sep 10, 2019
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21 changes: 20 additions & 1 deletion docs/react-testing-library/faq.md
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Expand Up @@ -126,7 +126,7 @@ If you want to make things more like shallow rendering, then you could do
something more [like this](example-react-transition-group.md).

Learn more about how Jest mocks work from my blog post:
["But really, what is a JavaScript mock?"](https://blog.kentcdodds.com/but-really-what-is-a-javascript-mock-10d060966f7d)
["But really, what is a JavaScript mock?"](https://kentcdodds.com/blog/but-really-what-is-a-javascript-mock)
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Just noticed this and couldn't help myself 🙃

</details>

Expand Down Expand Up @@ -178,6 +178,25 @@ snapshotDiff(firstVersion, container.cloneNode(true))

</details>

<details>

<summary>How do I fix "an update was not wrapped in act(...)" warnings?</summary>

This warning is usually caused by an async operation causing an update after
the test has already finished. There are 2 approaches to resolve it:

1. Wait for the result of the operation in your test by using one of
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Wanted to make sure people knew that any of the async utilities will solve this. And in many cases using a find* query makes a lot of sense, so I changed the example to that.
[the async utilities](/docs/dom-testing-library/api-async) like
[wait](/docs/dom-testing-library/api-async#wait) or a
[`find*` query](/docs/dom-testing-library/api-queries#findby). For example:
`const userAddress = await findByLabel(/address/i)`.
2. Mocking out the asynchronous operation so that it doesn't trigger state updates.

Generally speaking, approach 1 is preferred since it better matches the expectations
of a user interacting with your app.

</details>

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