runScript()

Wraps your experiment's entry function and guarantees the DOM is ready before execution.

Signature

runScript(fn: () => void | Promise<void>): void

Parameters

Parameter	Type	Description
fn	Function	The experiment logic to execute. Can be async.

Usage

Every variation entry point wraps its logic in runScript:

import { runScript } from 'create-experiment/framework';

runScript(async () => {
    // DOM is guaranteed to be ready here
    const target = document.querySelector('.my-selector');
    if (!target) return;

    // ... rest of experiment logic
});

Why it's needed

Adobe Target executes custom code as soon as it loads, which can happen before DOMContentLoaded. Without runScript, a document.querySelector call at the top level may return null even if the element exists later in the HTML.

runScript checks document.readyState and either runs the function immediately (if the DOM is already ready) or defers it to DOMContentLoaded:

const domReady = (callback) => {
    if (document.readyState !== 'loading') {
        callback();
    } else {
        document.addEventListener('DOMContentLoaded', callback);
    }
};

export const runScript = (fn) => {
    domReady(fn);
};

Async support

The fn argument can be an async function. This is the standard pattern when fetching product data:

runScript(async () => {
    const { data } = await fetchProductCard();
    if (!data) return;
    render(<ExperimentCard ... />, container);
});

Returns

void

runScript() does not await or return the callback result. Handle rejected promises inside async experiment logic when failure needs explicit reporting.

Since

v2.0.0

See Also

• waitFor() - poll until DOM selectors are present before proceeding
• watchFor() - MutationObserver-based alternative to waitFor