add checkoutShippingLineUpdateMutation

Author: isamu

Diff for: src/checkout-resource.js

@@ -17,6 +17,7 @@ import checkoutGiftCardsAppendMutation from './graphql/checkoutGiftCardsAppendMu
 import checkoutGiftCardRemoveV2Mutation from './graphql/checkoutGiftCardRemoveV2Mutation.graphql';
 import checkoutEmailUpdateV2Mutation from './graphql/checkoutEmailUpdateV2Mutation.graphql';
 import checkoutShippingAddressUpdateV2Mutation from './graphql/checkoutShippingAddressUpdateV2Mutation.graphql';
+import checkoutShippingLineUpdateMutation from './graphql/checkoutShippingLineUpdateMutation.graphql';
 
 /**
  * The JS Buy SDK checkout resource
@@ -333,6 +334,20 @@ class CheckoutResource extends Resource {
       .send(checkoutShippingAddressUpdateV2Mutation, {checkoutId, shippingAddress})
       .then(handleCheckoutMutation('checkoutShippingAddressUpdateV2', this.graphQLClient));
   }
+
+  /**
+   * Updates the shipping lines on an existing checkout.
+   *
+   * @param  {String} checkoutId The ID of the checkout to update shipping address.
+   * @param  {Object} shippingRateHandle A unique identifier to a Checkout’s shipping provide
+   * @return {Promise|GraphModel} A promise resolving with the updated checkout.
+   */
+  updateShippingLineAddress(checkoutId, shippingRateHandle) {
+    return this.graphQLClient
+      .send(checkoutShippingLineUpdateMutation, {checkoutId, shippingRateHandle})
+      .then(handleCheckoutMutation('checkoutShippingLineUpdate', this.graphQLClient));
+  }
+
 }
 
 export default CheckoutResource;

Diff for: src/graphql/checkoutShippingLineUpdateMutation.graphql

@@ -0,0 +1,15 @@
+mutation checkoutShippingLineUpdate($checkoutId: ID!, $shippingRateHandle: String!) {
+  checkoutShippingLineUpdate(
+    checkoutId: $checkoutId
+    shippingRateHandle: $shippingRateHandle
+  ) {
+    checkout {
+      id
+    }
+    checkoutUserErrors {
+      code
+      field
+      message
+    }
+  }
+}