Presets

Presets are reusable ChaosConfig objects exported from @chaos-maker/core.

import { presets } from '@chaos-maker/core';
import { injectChaos } from '@chaos-maker/playwright';

await injectChaos(page, presets.slowNetwork);

When to use presets

Use presets for smoke coverage and exploratory resilience tests. Use explicit configs for product-critical flows where the exact status code, selector, message direction, and probability matter.

Common pattern

await injectChaos(page, {
  ...presets.unstableApi,
  seed: 42,
});

The seed belongs at the root config level, so it can be added to any preset before injection.

Built-in presets

Preset	Surface	Use case
unstableApi	Network	Occasional API failures and latency.
slowNetwork	Network	All requests are delayed.
offlineMode	Network	Requests fail like an offline browser.
flakyConnection	Network	Rare aborts and latency.
degradedUi	UI	Buttons and links are disabled or hidden.
unreliableWebSocket	WebSocket	Drops, delays, and corrupts socket messages.
unreliableEventStream	SSE	Drops, delays, and occasionally closes EventSource streams.

Presets are plain config objects. You can spread them and add a seed or extra rules.