update promotion-util-test.js
add cart-test.js #addCartItem() test
update cart.js bug
format promotion-util-test.js
format scanner-test.js
format promotion-util-test.js
add #getgetCartItemsText() test to  cart-test.js
format promotion-util-test
add #getCartItemsText() test to cart-test.js
format cart-test.js
add #getPromotionsText() test to cart-test.js
finish cart-test test
format item-test
add getPromotionText() cart-test test