Available since v0.1.0

Solid

Stable

SolidJS uses JSX, but unlike React, Solid compiles JSX to real DOM operations — there's no virtual DOM. fs-* attributes pass through to native elements without configuration.

Install

Load the agent via a <script> tag. Initialize in your entry point:

// src/index.jsx
import { render } from 'solid-js/web';
import App from './App';

render(() => <App />, document.getElementById('root'));

Faultsense.init({
  releaseLabel: import.meta.env.VITE_RELEASE,
  collectorURL: '/events',
  apiKey: import.meta.env.VITE_FS_KEY,
});

JSX binding

Static attributes are plain strings:

<button
  fs-assert="cart/add-item"
  fs-trigger="click"
  fs-assert-updated="#cart-count"
  onClick={handleAddToCart}>
  Add to cart
</button>

Dynamic attributes use expressions. Solid's fine-grained reactivity re-evaluates only the parts that change:

<input type="checkbox"
  fs-assert="todos/toggle"
  fs-trigger="change"
  fs-assert-updated={`.todo-item[classlist=completed:${!todo.completed}]`}
  checked={todo.completed}
  onChange={onToggle} />

Signals and reactivity

Solid's signals produce fine-grained DOM updates — often a single characterData or attributes mutation with no ancestor changes. The agent handles this via PAT-06 text-only mutation, which promotes characterData record targets to their parentElement so text-matches modifiers work without targeting text nodes directly.

const [count, setCount] = createSignal(0);

<button
  fs-assert="counter/increment"
  fs-trigger="click"
  fs-assert-updated='#count[text-matches=\d+]'
  onClick={() => setCount(c => c + 1)}>
  +
</button>
<div id="count">{count()}</div>

When setCount triggers, Solid updates just the text node inside #count. The agent's updated resolver sees the text mutation and matches against #count.

Dynamic assertion values

Compute the expected next state in the expression:

<input type="checkbox"
  fs-assert="todos/toggle-complete"
  fs-trigger="change"
  fs-assert-updated={`.todo-item[classlist=completed:${!todo.completed}]`} />

Gotchas