# react-proxy-hook

> Helps you test a React Hook

Latest version **0.4.2** (published 2019-01-22) · MIT license · 0 weekly downloads

## Install

```sh
npm install react-proxy-hook
pnpm add react-proxy-hook
yarn add react-proxy-hook
bun add react-proxy-hook
```

## Health

**Score 15/100 (F)** — status: abandoned.

Positive: no vulnerabilities.

Warnings: low downloads; no types; no esm support; pre 1.0.

Negative: abandoned; low maintenance score.

## Facts

| | |
|---|---|
| Version | 0.4.2 |
| Published | 2019-01-22 |
| First published | 2019-01-18 |
| Weekly downloads | 0 |
| License | MIT |
| TypeScript types | none |
| Module format | CommonJS |
| Dependencies | 1 |
| Unpacked size | 9.3 KB |
| Known vulnerabilities | 0 |
| Install scripts | no |
| GitHub stars | 5 |
| Author | donavon |
| Maintainers | donavon |
| Keywords | react-hooks, hooks, react, utils |

## Links

- npm: https://www.npmjs.com/package/react-proxy-hook
- Repository: https://github.com/donavon/react-proxy-hook
- Homepage: https://github.com/donavon/react-proxy-hook#readme
- Issues: https://github.com/donavon/react-proxy-hook/issues
- npm.io page: https://npm.io/package/react-proxy-hook

## Dependencies (1)

- [react-testing-library](https://npm.io/package/react-testing-library.md) ^5.4.4

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## Recent versions

- 0.4.2 (latest) — 2019-01-22
- 0.4.0 — 2019-01-22
- 0.3.0 — 2019-01-21
- 0.2.0 — 2019-01-21
- 0.1.1 — 2019-01-18
- 0.1.0 — 2019-01-18
- 0.0.3 — 2019-01-18
- 0.0.2 — 2019-01-18
- 0.0.1 — 2019-01-18

## README

# react-proxy-hook

Helps you test a React Hook

[![npm version](https://badge.fury.io/js/react-proxy-hook.svg)](https://badge.fury.io/js/react-proxy-hook)

## Requirement ⚠️

To use `react-proxy-hook`, you must use `react@16.8.0-alpha.1`. React Hooks is currently at
**[RFC](https://github.com/reactjs/rfcs/pull/68)** stage.

## Installation

```bash
$ npm i -D react-proxy-hook
```

## Usage

`react-proxy-hook` is a wrapper around Kent C. Dodd's `react-testing-library`.
It was inspired by the `setup` function that Kent wrote in his
[YouTube video](https://youtu.be/0e6WCQYg5tU).
It is presented here as a simple React Hooks function wrapper.

Hooks can not be tested as standalone functions as they will not work
unless they are called from withing a rendered component.
`react-proxy-hook` gets around this limitation by proxying an actual
component.

> Maybe should have been called a HOH (Higher Order Hook)?

Look at how easy testing a Hook can be!

## Method 1: `testHook`

Method 1 requires that you place the call to your cutom Hook inside of a callback function. You then destructure (or not) your data into a `let` that you previously defined.

```js
import { testHook, cleanup } from 'react-proxy-hook';
import useCounter from '../use-counter';

afterEach(cleanup);

test('useCounter', () => {
  let count, increment;
  testHook(() => ({ count, increment } = useCounter({ initialCount: 2 })));

  expect(count).toBe(2);
  increment();
  expect(count).toBe(3);
});
```

Using Method 1 (suggested), there are no restrictions on destructuring.

I've [made a PR](https://github.com/kentcdodds/react-testing-library/pull/274)
into `react-testing-library` for this, so hopefully this will be in merged soon.

See the test for Method 1 running live on CodeSandbox.

[![Edit React Codesandbox](https://codesandbox.io/static/img/play-codesandbox.svg)](https://codesandbox.io/s/6lqxvx42mz?module=%2Fsrc%2F__tests__%2Fuse-counter.js)

## Method 2: `proxyHook`

You test your Hook just like you would use it in an actual component.
Just pass your actual hook to `proxyHook` and it will return
a proxied version of your hook.

```js
import { proxyHook, cleanup } from 'react-proxy-hook';
import useCounter from '../use-counter';

const useCounterProxy = proxyHook(useCounter);

afterEach(cleanup);

test('useCounter', () => {
  const counterData = useCounterProxy();
  counterData.increment();
  expect(counterData.count).toBe(1);
  counterData.decrement();
  expect(counterData.count).toBe(0);
});
```

See the test for Method 2 running live on CodeSandbox.

[![Edit demo app on CodeSandbox](https://codesandbox.io/static/img/play-codesandbox.svg)](https://codesandbox.io/s/6lqxvx42mz)

### Testing objects

To test with a returned object (ex: `{ foo: 'bar' }` ) use the dot notation.

```js
const returnedVal = useFooProxy();
expect(returnedVal.foo).toBe('bar');
```

### Testing arrays

To test with a returned array (ex: `[0]` ) use bracket notation.

```js
const returnedVal = useFooProxy();
expect(returnedVal[0]).toBe(0);
```

### Testing other types

To test with other returned types (i.e. string, numbers, `null`, `undefined`), use they key "value".

```js
const returnedVal = useFooProxy();
expect(returnedVal.value).toBe('foo');
```

### Limitations

You must not deconstruct the returned value in your test.
For example, the following wo't work as `count` will still be `0`.

```js
const { count, increment } = useCounterProxy(0);
increment();
expect(count).toBe(1);
```

## License

**[MIT](LICENSE)** Licensed

---

Obviously, none of this would not be possible without the tireless work of
Kent C. Dodds. Thank you! 🙏

---
_Source: https://npm.io/package/react-proxy-hook · Machine-readable twin of the npm.io package page. Health data is recomputed on every publish._