woocommerce-paypal-payments/modules/ppcp-settings/resources/js/utils/Helper/SimulateCart.js

class SimulateCart {
	constructor( endpoint, nonce ) {
		this.endpoint = endpoint;
		this.nonce = nonce;
	}

	/**
	 *
	 * @param             onResolve
	 * @param {Product[]} products
	 * @return {Promise<unknown>}
	 */
	simulate( onResolve, products ) {
		return new Promise( ( resolve, reject ) => {
			fetch( this.endpoint, {
				method: 'POST',
				headers: {
					'Content-Type': 'application/json',
				},
				credentials: 'same-origin',
				body: JSON.stringify( {
					nonce: this.nonce,
					products,
				} ),
			} )
				.then( ( result ) => {
					return result.json();
				} )
				.then( ( result ) => {
					if ( ! result.success ) {
						reject( result.data );
						return;
					}

					const resolved = onResolve( result.data );
					resolve( resolved );
				} );
		} );
	}
}

export default SimulateCart;