Updated hooks reference #2524
Updated hooks reference #2524
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Added a note about throwing an error in default switch case in `useReducer`, as per Dan's [tweet](https://twitter.com/dan_abramov/status/1093969005675773954) and [this issue](reactjs#2159)
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| >React guarantees that `dispatch` function identity is stable and won't change on re-renders. This is why it's safe to omit from the `useEffect` or `useCallback` dependency list. | |||
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| >Note | |||
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| >Unlike reducers in Redux or similar state managing solution, actions in `useReducer` are specific to a component. Hence, it is recommended that you **throw an error in the default switch case**. It can help you track bugs in early stages (for example, mistakes in action references). | |||
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Switch case is one way to write a reducer, but there are others, like an object literal.
| >Unlike reducers in Redux or similar state managing solution, actions in `useReducer` are specific to a component. Hence, it is recommended that you **throw an error in the default switch case**. It can help you track bugs in early stages (for example, mistakes in action references). | |
| >Unlike reducers in Redux or similar state managing solution, actions in `useReducer` are specific to a component. Hence, it is recommended that you **treat unknown action types as errors** rather than handling them with a default value. It can help you track bugs in early stages (for example, mistakes in action references). |
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Also, might be worth mentioning how Flow and Typescript can help prevent dispatching unknown action types.
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I find React docs don't make many references to Typescript, they stay pretty agnostic (although I do agree that it's very helpful). Do you still think it's a good idea to add it? I could work it in.
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There are a few and this area is one where a type system can specifically help identify either an unhandled state or runtime error.
Added a note about throwing an error in default switch case in
useReducer, as per Dan's tweet and this issue