Now, let's document the cart section with the list of products in the cart:

  @ApiOperation(value = "List the product in the cart", consumes = 
    "text/plain")
  @ApiResponses(Array(new ApiResponse(code = 200, message = "Product 
    added"),
    new ApiResponse(code = 401, message = "unauthorized, please login 
    before to proceed"),
    new ApiResponse(code = 500, message = "Internal server error, 
    database error")))
  def listCartProducts() = Action.async { request =>

If we call listCartProducts, we receive an empty array. To test it with some products, complete the declaration of addCartProduct with the following:

  @ApiOperation(value = "Add a product in the cart", consumes = 
    "text/plain")
  @ApiResponses(Array(new ApiResponse(code = 200, message = "Product 
    added in the cart"),
    new ApiResponse(code = 400, message = "Cannot insert duplicates in 
    the database"),
    new ApiResponse(code = 401, message = "unauthorized, please login 
    before to proceed"),
    new ApiResponse(code = 500, message = "Internal server error, 
    database error")))
  def addCartProduct(
         @ApiParam(name = "id", value = "The product code", required = 
            true) id: String,
         @ApiParam(name = "quantity", value= "The quantity to add", 
            required = true) quantity: String) = Action.async { request 
            =>

In Swagger, we can now add a new product to the cart, as follows:

Then, the list of products will return the following:

After that, we can try to update a product. Add the following annotations to updateCartProduct:

  @ApiOperation(value = "Update a product quantity in the cart", 
    consumes = "text/plain")
  @ApiResponses(Array(new ApiResponse(code = 200, message = "Product 
    added in the cart"),
    new ApiResponse(code = 401, message = "unauthorized, please login 
    before to proceed"),
    new ApiResponse(code = 500, message = "Internal server error, 
    database error")))
  def updateCartProduct(@ApiParam(name = "id", value = "The product 
    code", required = true, example = "ALD1") id: String, 
    @ApiParam(name = "quantity", value= "The quantity to update", 
    required = true) quantity: String) = Action.async { request =>
  

Then, use Swagger to update the quantity, as follows:

After the update, the list of products returns, as follows:

Perfect; the last operation to document is deleteCartProduct:

  @ApiOperation(value = "Delete a product from the cart", consumes = 
    "text/plain")
  @ApiResponses(Array(new ApiResponse(code = 200, message = "Product 
    delete from the cart"),
    new ApiResponse(code = 401, message = "unauthorized, please login 
    before to proceed"),
    new ApiResponse(code = 500, message = "Internal server error, 
    database error")))
  def deleteCartProduct(@ApiParam(name = "id", value = "The product 
    code", required = true) id: String) = Action.async { request =>

We now have complete Swagger documentation for our API, and users can test it directly from their browsers.