Chaos (for testing)

This package contains an adapter decorator that causes instrumented failures. This is useful for when you want to make sure your application code can deal with failures gracefully.

Use the chaos adapter decorator to wrap your actual adapter and instruct it to throw errors. Use it to validate retry mechanisms, logging, and metric collection to gain better insights into the functioning of your application.

Installation

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

Setup

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);

Usage

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});