Files
react/compiler/apps/playground/lib/createContext.ts
Jan Kassens fd2b3e13d3 Compiler: unfork prettier config (#30205)
Updates the prettier config to format all `.ts` and `.tsx` files in the
repo using the existing defaults and removing overrides.

The first commit in this PR contains the config changes, the second is
just the result of running `yarn prettier-all`.
2024-07-18 17:00:24 -04:00

38 lines
1021 B
TypeScript

/**
* Copyright (c) Meta Platforms, Inc. and affiliates.
*
* This source code is licensed under the MIT license found in the
* LICENSE file in the root directory of this source tree.
*/
import React from 'react';
/**
* Replacement to React.createContext.
*
* Does not take any default value and avoids non-null assertions when using
* the value of the context, like the following scenario.
*
* ```ts
* const StoreDispatchContext = useContext<Dispatch<ReducerAction>>(null);
* const dispatchStore = useContext(StoreDispatchContext);
* ...
* dipatchStore!({ ... });
* ```
*
* Instead, it throws an error when `useContext` is not called within a
* Provider with a value.
*/
export default function createContext<T>() {
const context = React.createContext<T | null>(null);
function useContext() {
const c = React.useContext(context);
if (!c)
throw new Error('useContext must be within a Provider with a value');
return c;
}
return {useContext, Provider: context.Provider};
}