Fetch request for REST API

fetch.js

// Exported from php.
const exports = {
	restBase: {
		url: 'https://example.org/wp-json/wp/v2',
		nonce: '3433DFE2',
	}
};

// Utils function.
const getRestUrl = ( endpoint, params ) => {
	const url = `${ exports.restBase.url }/${ endpoint }?_wpnonce=${ exports.restBase.nonce }`;

	return Object.keys( params ).reduce( ( accum, key ) => accum + `&${ key }=${ params[ key ] }`, url );
};

const restUrl = getRestUrl( 'end-point', {
	term_id: 23,
	posts_per_page: 15,
} );

fetch( restUrl, { headers: { 'X-WP-Nonce': exports.restBase.nonce },
} ).then( response => response.json() ).then( resp => {
	// Render JS template and append to DOM using resp.
} );