Increment Item Quantity

Use the incrementItemQuantity mutation to increment only the cart item quantity.

Mutation

incrementItemQuantity(input: UpdateItemQuantityInput!): Cart!

UpdateItemQuantityInput

Argument	Type	Description
`cartId`	`ID!`	The id of the cart you are working with
`id`	`ID!`	The id of the item you are incrementing
`by`	`Int!`	The amount to increment by

Example

mutation {
  incrementItemQuantity(
    input: { cartId: "ck5r8d5b500003f5o2aif0v2b", id: "5e3293a3462051", by: 10 }
  ) {
    id
    items {
      id
      quantity
    }
  }
}