Schema level errors do not contain data or model properties

fixtures/checkout-create-invalid-variant-id-error-fixture.js

@@ -0,0 +1,7 @@
+export default {
+  "errors": [
+    {
+      "message": "Variable input of type CheckoutCreateInput! was provided invalid value"
+    }
+  ]
+}

src/handle-checkout-mutation.js

@@ -1,5 +1,5 @@
 export default function handleCheckoutMutation(mutationRootKey, client) {
-  return function({data, errors, model}) {
+  return function({data = {}, errors, model = {}}) {
     const rootData = data[mutationRootKey];
     const rootModel = model[mutationRootKey];
 

test/client-checkout-integration-test.js

@@ -7,6 +7,7 @@ import fetchMockPostOnce from './fetch-mock-helper';
 import checkoutFixture from '../fixtures/checkout-fixture';
 import checkoutNullFixture from '../fixtures/node-null-fixture';
 import checkoutCreateFixture from '../fixtures/checkout-create-fixture';
+import checkoutCreateInvalidVariantIdErrorFixture from '../fixtures/checkout-create-invalid-variant-id-error-fixture';
 import checkoutCreateWithPaginatedLineItemsFixture from '../fixtures/checkout-create-with-paginated-line-items-fixture';
 import {secondPageLineItemsFixture, thirdPageLineItemsFixture} from '../fixtures/paginated-line-items-fixture';
 import checkoutLineItemsAddFixture from '../fixtures/checkout-line-items-add-fixture';
@@ -101,6 +102,25 @@ suite('client-checkout-integration-test', () => {
     });
   });
 
+  test('it resolve with user errors on Client.checkout#create when variantId is invalid', () => {
+    const input = {
+      lineItems: [
+        {
+          variantId: 'a-bad-id',
+          quantity: 5
+        }
+      ]
+    };
+
+    fetchMockPostOnce(fetchMock, apiUrl, checkoutCreateInvalidVariantIdErrorFixture);
+
+    return client.checkout.create(input).then(() => {
+      assert.ok(false, 'Promise should not resolve');
+    }).catch((error) => {
+      assert.equal(error.message, '[{"message":"Variable input of type CheckoutCreateInput! was provided invalid value"}]');
+    });
+  });
+
   test('it resolves with a checkout on Client.checkout#updateAttributes', () => {
     const checkoutId = 'Z2lkOi8vU2hvcGlmeS9FeGFtcGxlLzE=';
     const input = {