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https://github.com/thadeu/jest-localstack-preset

🥾 A simple way to do testing AWS Services and Jest or Serverless and Jest
https://github.com/thadeu/jest-localstack-preset

jest jest-aws jest-dynamodb jest-serverless localstack serverless

Last synced: 28 days ago
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🥾 A simple way to do testing AWS Services and Jest or Serverless and Jest

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# jest-localstack-preset

🥾 A simple way to do testing AWS Services and Jest or Serverless and Jest

[![ci](https://github.com/thadeu/jest-localstack-preset/actions/workflows/ci.yml/badge.svg?branch=main)](https://github.com/thadeu/jest-localstack-preset/actions/workflows/ci.yml)
[![Npm package version](https://badgen.net/npm/v/@thadeu/jest-localstack-preset)](https://www.npmjs.com/package/@thadeu/jest-localstack-preset)

## Install

Install via yarn or npm

```bash
$ yarn add -D @thadeu/jest-localstack-preset
```

or

```bash
$ npm i -D @thadeu/jest-localstack-preset
```

## Dependencies

- Docker
- [LocalStack Image](https://docs.localstack.cloud/get-started/#starting-localstack-with-docker)
- NodeJS >= 12.x

## Configuration

Configure `jest.config.js`, adding a custom `preset` and `setupFiles`

```js
module.exports = {
preset: '@thadeu/jest-localstack-preset',
setupFiles: ['./jest.setup.js'],
...
}
```

Create `jest.localstack.js` file with your required services, for example.

```js
module.exports = {
services: ['dynamodb', 'kinesis', 's3', 'apigateway', 'lambda'],
showLog: false,
readyTimeout: 10000,
autoPullImage: true,
S3Buckets: [
{
Bucket: 'examplebucket',
},
],
DynamoDB: [
{
TableName: `users_test`,
BillingMode: 'PAY_PER_REQUEST',
KeySchema: [
{ AttributeName: 'pk', KeyType: 'HASH' },
{ AttributeName: 'sk', KeyType: 'RANGE' },
],
AttributeDefinitions: [
{ AttributeName: 'pk', AttributeType: 'S' },
{ AttributeName: 'sk', AttributeType: 'S' },
],
},
],
}
```

| Key | Value | Description |
| ------------- | -------- | -------------------------------------------------- |
| readyTimeout | boolean | Define timeout in milliseconds to create container |
| autoPullImage | boolean | Define if we go to download image automatically |
| showLog | boolean | Define show logs for localstack |
| services | [string] | List of AWS Services |

> You can define environment `JEST_LOCALSTACK_AUTO_PULLING` to precede autoPullImage configuration in your CI/CD

Create a file `jest.setup.js`

```js
const AWS = require('aws-sdk')

const { configureMockSDK } = require('@thadeu/jest-localstack-preset/aws')
configureMockSDK(AWS)
```

## Usage

When you use `configureMockSDK` function, we configure many things to you transparently. This means that you going to use `aws-sdk` normally, without change.

> We will apply yhis

```js
{
accessKeyId: 'access-key',
secretAccessKey: 'secret-key',
region: 'us-east-1',
endpoint: 'http://localhost:4566',
s3ForcePathStyle: true,
}
```

But, if you need configure in runtime, enjoy and to do that. Anywhere you can use the `endpoint_url` to access localstack services locally.

So, use custom endpoint `process.env.AWS_ENDPOINT_URL` for general or specific to DynamoDB `process.env.AWS_DYNAMODB_ENDPOINT_URL` in the AWS clients in your code.

For example to use DynamoDB or S3.

```js
const AWS = require('aws-sdk')

const Table = new AWS.DynamoDB.DocumentClient({
endpoint: process.env.AWS_DYNAMODB_ENDPOINT_URL,
})
```

So, create your tests using Jest.

An example for DynamoDB.

```js
const AWS = require('aws-sdk')

const Table = new AWS.DynamoDB.DocumentClient({
endpoint: process.env.AWS_DYNAMODB_ENDPOINT_URL,
})

it('should insert item into table', async () => {
await Table.put({
TableName: 'users_test',
Item: { pk: '1', sk: 'jest-localstack-preset' },
}).promise()

const { Count } = await Table.scan({ TableName: 'users_test' }).promise()
expect(Count).toBe(1)
})
```

An example for S3

```js
const AWS = require('aws-sdk')

const s3 = new AWS.S3({
endpoint: process.env.AWS_ENDPOINT_URL,
s3ForcePathStyle: true,
})

it('must be create a bucket', async () => {
await s3.createBucket({ Bucket: 'examplebucket' }).promise()

const { Buckets } = await s3.listBuckets().promise()

expect(Buckets.length).toBe(1)
expect(Buckets[0].Name).toBe('examplebucket')
})
```

Usually you go to use other files, class and functions.

```js
// UserReposity.js
const AWS = require('aws-sdk')

// =================================================
// WITH configureMockSDK in your setupFiles
// =================================================
const Table = new AWS.DynamoDB.DocumentClient()

// =================================================
// WITHOUT configureMockSDK
// =================================================
// const Table = new AWS.DynamoDB.DocumentClient({
// endpoint: process.env.AWS_DYNAMODB_ENDPOINT_URL,
// region: process.env.AWS_REGION,
// })

export default class UserReposity {
static async all(props = {}) {
return Table.scan({ TableName: 'users', ...props }).promise()
}

static async save(props) {
return Table.put({
TableName: 'users',
...props,
}).promise()
}
}

// UserReposity.test.js
import UserReposity from './UserReposity'

describe('UserReposity', function() {
it('should insert item into repository', async () => {
await UserReposity.save({
Item: { pk: '1', sk: 'jest-localstack-preset' },
})

const { Count } = await UserReposity.all()
expect(Count).toBe(1)
})
})
```

In this moment, all process will be make using [LocalStack](https://github.com/localstack/localstack).

## How Its Works?

Programmatically, we start a docker container with localstack, we run all tests and then, when tests finished, we destroy all containers related

## What services work?

Basically, whatever!

For more AWS Service available visit, https://docs.localstack.cloud/aws/feature-coverage/

## Debugging

You can enabled debug flag using your custom environment.

| Envs | Type |
| ---------------------------- | ------- |
| LOCALSTACK_DEBUG | boolean |
| JEST_LOCALSTACK_AUTO_PULLING | boolean |

## CI (Continuous Integration)

- Github Actions, see [.github/workflows/ci](.github/workflows/ci.yml)

Simple example

```yml
name: ci

on: push

jobs:
jest:
name: jest
runs-on: ubuntu-latest

services:
localstack:
image: localstack/localstack

defaults:
run:
working-directory: ./

steps:
- uses: actions/checkout@v2

- uses: actions/cache@v2
with:
path: '**/node_modules'
key: ${{ runner.os }}-modules-${{ hashFiles('**/yarn.lock') }}
restore-keys: |
${{ runner.os }}-modules-

- name: Setup NodeJS
uses: actions/setup-node@v2
with:
node-version: 14.17.x

- name: Install Yarn Dependencies
run: yarn install --frozen-lockfile

- name: Yarn Jest
run: yarn test
env:
LOCALSTACK_DEBUG: true
JEST_LOCALSTACK_AUTO_PULLING: true
```

## Disclaimer

This project is based on the amazing project https://github.com/goldsam/jest-localstack.

## Contributing

Once you've made your great commits (include tests, please):

1. Fork this repository
2. Create a topic branch - git checkout -b my_branch
3. Push to your branch - git push origin my_branch
4. Create a pull request
5. That's it!

Please respect the indentation rules and code style. And use 2 spaces, not tabs. And don't touch the version thing or distribution files; this will be made when a new version is going to be release

## License

The Dockerfile and associated scripts and documentation in this project are released under the [MIT License](LICENSE).