https://github.com/doniyor2109/jest-generator

Testing generator function never been easy
https://github.com/doniyor2109/jest-generator

assertions generator generator-function generator-functions generators jest jest-matchers testing

Last synced: about 2 months ago
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Testing generator function never been easy

• Host: GitHub
• URL: https://github.com/doniyor2109/jest-generator
• Owner: doniyor2109
• License: mit
• Created: 2018-11-14T06:33:11.000Z (over 5 years ago)
• Default Branch: master
• Last Pushed: 2021-04-08T05:10:45.000Z (about 3 years ago)
• Last Synced: 2024-05-09T07:54:23.392Z (about 2 months ago)
• Topics: assertions, generator, generator-function, generator-functions, generators, jest, jest-matchers, testing
• Language: JavaScript
• Homepage: https://www.npmjs.com/package/jest-generator
• Size: 189 KB
• Stars: 30
• Watchers: 3
• Forks: 3
• Open Issues: 1
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

Lists

• awesome-jest - jest-generator

README

        
# jest-generator

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[![Build Status](https://travis-ci.com/doniyor2109/jest-generator.svg?branch=master)](https://travis-ci.com/doniyor2109/jest-generator)

[![GitHub](https://img.shields.io/github/license/mashape/apistatus.svg)](https://github.com/doniyor2109/jest-generator/blob/master/LICENSE)

[![PRs Welcome](https://img.shields.io/badge/PRs-welcome-brightgreen.svg)](https://github.com/doniyor2109/jest-generator/pulls) 

Testing generators are verbose as they require calling `next` method of generator each time you want to iterate. `jest-generator` encapsulates all iteration and assertion logic itself. It provides easy and readable API for testing generator functions.

![Testing with jest-generator](https://raw.githubusercontent.com/doniyor2109/jest-generator/master/jest-generator-example.png)

# Installation

```bash

yarn add --dev jest-generator

```

or

```bash

npm install --save-dev jest-generator

```

# Setup

#### Via `setupTestFrameworkScriptFile` config

Add `jest-generator` to your Jest `setupTestFrameworkScriptFile` configuration

```json

"jest": {

  "setupTestFrameworkScriptFile": "jest-generator"

}

```

#### Via `setupTest` script

Require `jest-generator` from setupTest script

```js

// ./setupTest.js

require('jest-generator');

```

Then add this config

```json

"jest": {

  "setupTestFrameworkScriptFile": "./setupTest.js"

}

```

# Usage

```js

// ./pay.js

export default function* pay() {

  yield validatePayment();

  yield makePayment();

  return finishPayment();

}

```

```js

// ./pay.test.js

import pay from './pay';

test('should work correctly', () => {

  const iterator = pay();

  expect(iterator).toMatchYields([

    [validatePayment()],

    [makePayment()],

    [finishPayment()]

  ]);

});

```

# Usage with other libraries

## Usage with Saga

 

```js

// ./books.js

export function* loadBooks(params) {

  try {

    const response = yield call(api.loadBooks, params)

    

    yield put(booksLoadedSuccess(response))

  } catch (error) {

    yield put(booksLoadFail(error.message))

  }

}

```

```js

// ./books.test.js

import { loadBooks } from './books';

test('should handle success response', () => {

  const params = { id: 201 };

  const iterator = loadBooks(params);

  const response = [];

  expect(iterator).toMatchYields([

    [call(api.loadBooks, params), response],

    [booksLoadedSuccess(response)],

  ]);

});

test('should handle error response', () => {

  const params = { id: 201 };

  const iterator = loadBooks(params);

  const response = new Error('failed to load books');

  expect(iterator).toMatchYields([

    [call(api.loadBooks, params), response],

    [put(booksLoadFail(response.message))],

  ]);

});

```

# API

```js

.toMatchYields(

  yieldValues: [

    [yieldValue: any, returnType?: any | Error]

  ]

)

```

Matches iterator against given yield values

```js

expect(iterator).toMatchYields([

  [callAPI()]

])

```

In order to return value from yield, simply pass your return value as second array value

```js

function* gen() {

  const response = yield fetch()

  yield update(response)

}

const mockResponse = {};

const iterator = gen();

expect(iterator).toMatchYields([

  [fetch(), mockResponse],

  [update(mockResponse)]

])

```

In order to throw error from yield, you should simply pass `Error` instance to return type

```js

function* gen() {

  const response = yield fetch()

  yield update(response)

}

const mockErrorResponse = new Error('network error');

const iterator = gen();

expect(iterator).toMatchYields([

  [fetch(), mockErrorResponse],

  [handleError(mockErrorResponse)]

])

```

 

# Licence

This project is licensed under the MIT License - see the [LICENSE](LICENSE) file for details