@wordpress/hooks/src/createHasHook.js

WordPress hooks library.

/**
 * @callback HasHook
 *
 * Returns whether any handlers are attached for the given hookName and optional namespace.
 *
 * @param {string} hookName    The name of the hook to check for.
 * @param {string} [namespace] Optional. The unique namespace identifying the callback
 *                             in the form `vendor/plugin/function`.
 *
 * @return {boolean} Whether there are handlers that are attached to the given hook.
 */
/**
 * Returns a function which, when invoked, will return whether any handlers are
 * attached to a particular hook.
 *
 * @param {import('.').Hooks}    hooks    Hooks instance.
 * @param {import('.').StoreKey} storeKey
 *
 * @return {HasHook} Function that returns whether any handlers are
 *                   attached to a particular hook and optional namespace.
 */
function createHasHook( hooks, storeKey ) {
	return function hasHook( hookName, namespace ) {
		const hooksStore = hooks[ storeKey ];

		// Use the namespace if provided.
		if ( 'undefined' !== typeof namespace ) {
			return (
				hookName in hooksStore &&
				hooksStore[ hookName ].handlers.some(
					( hook ) => hook.namespace === namespace
				)
			);
		}

		return hookName in hooksStore;
	};
}

export default createHasHook;