Profiles

Save and reuse chaos configurations

Profiles allow you to save and reuse chaos configurations, making it easy to switch between different testing scenarios.

Create a profile

import { cruel } from "cruel"

// Define a testing profile
cruel.profile("testing", {
  fail: 0.2,
  delay: [100, 500],
  timeout: 0.05,
})

// Define a production profile
cruel.profile("production", {
  fail: 0.01,
  delay: [10, 50],
})

// Define a stress test profile
cruel.profile("stress", {
  fail: 0.5,
  delay: [1000, 5000],
  timeout: 0.2,
  jitter: 1000,
})

Use a profile

// Activate a profile
cruel.useProfile("testing")

// All wrapped functions now use this profile
const api = cruel(fetch)
await api("https://api.example.com")

// Switch to different profile
cruel.useProfile("stress")
await api("https://api.example.com") // Much more chaos

Environment-based profiles

import { cruel } from "cruel"

// Set up profiles
cruel.profile("development", cruel.presets.development)
cruel.profile("staging", cruel.presets.staging)
cruel.profile("production", cruel.presets.production)

// Activate based on environment
const env = process.env.NODE_ENV || "development"
cruel.useProfile(env)

Feature-specific profiles

import { cruel } from "cruel"

// API testing profile
cruel.profile("api-testing", {
  fail: 0.1,
  delay: [100, 500],
  timeout: 0.05,
})

// Database testing profile
cruel.profile("db-testing", {
  fail: 0.05,
  delay: [50, 200],
  timeout: 0.02,
})

// Stream testing profile
cruel.profile("stream-testing", {
  fail: 0.1,
  delay: [200, 1000],
  corrupt: 0.05,
})

// Use different profiles for different tests
test("API handles failures", () => {
  cruel.useProfile("api-testing")
  // Test API
})

test("Database handles failures", () => {
  cruel.useProfile("db-testing")
  // Test database
})

Team profiles

// profiles.ts - Shared team configurations
import { cruel } from "cruel"

export const profiles = {
  backend: {
    fail: 0.1,
    delay: [100, 500],
  },
  frontend: {
    fail: 0.05,
    delay: [50, 200],
  },
  integration: {
    fail: 0.2,
    delay: [200, 1000],
    timeout: 0.1,
  },
}

// Register all profiles
Object.entries(profiles).forEach(([name, config]) => {
  cruel.profile(name, config)
})

// test.ts - Use team profiles
import { cruel } from "cruel"
import "./profiles"

test("backend integration", () => {
  cruel.useProfile("backend")
  // Tests
})

Dynamic profiles

import { cruel } from "cruel"

// Create profile from environment variables
const customProfile = {
  fail: parseFloat(process.env.CHAOS_FAIL || "0.1"),
  delay: [
    parseInt(process.env.CHAOS_DELAY_MIN || "100"),
    parseInt(process.env.CHAOS_DELAY_MAX || "500"),
  ] as [number, number],
  timeout: parseFloat(process.env.CHAOS_TIMEOUT || "0.05"),
}

cruel.profile("custom", customProfile)
cruel.useProfile("custom")

Reset profiles

// Reset clears all profiles
cruel.reset()

// Need to recreate profiles after reset
cruel.profile("testing", { fail: 0.1 })

Profiles are stored globally and persist until cruel.reset() is called.

Combine profiles with presets to create comprehensive testing configurations.