@flystorage/chaos/README.md

A storage adapter decorator with the ability to stage errors.

<img src="https://raw.githubusercontent.com/duna-oss/flystorage/main/flystorage.svg" width="50px" height="50px" />

# Flystorage adapter for chaos engineering

This package contains an adapter decorator that causes instrumented failures.

## Installation

Install all the required packages

```bash
npm install --save @flystorage/file-storage @flystorage/chaos
```

## Setup

```typescript
import {FileStorage} from '@flystorage/file-storage';
import {ChaosStorageAdapterDecorator, TriggeredErrors} from '@flystorage/chaos';

const strategy = new TriggeredErrors();
const adapter = new ChaosStorageAdapterDecorator(
    createActualAdapter(),
    strategy,
);
const storage = new FileStorage(adapter);
```

> ⚠️ Always use the FileStorage, it is essential for security and a good developer
> experience. Do not use the adapter directly.
 
## Usage

```typescript

import {TriggeredErrors} from '@flystorage/chaos';

const strategy = new TriggeredErrors();

// error on all write calls
strategy.on('write', () => new Error());

// error on first 2 stat calls
strategy.on('stat', () => new Error(), {times: 2});

// error after first 2 deleteFile calls
strategy.on('deleteFile', () => new Error(), {after: 2});

// error on 2nd and 3rd call to any method
strategy.on('*', () => new Error(), {after: 1, times: 2});
```