Unwrap non-null returnType during mutations

Author: jgwhite

addon/mocks/mutation.js

@@ -1,4 +1,4 @@
-import { contextSet, isFunction, reduceKeys } from '../utils';
+import { contextSet, isFunction, reduceKeys, unwrapNonNull } from '../utils';
 import { getRecords } from '../db';
 import { resolveVarName } from '../filter/vars';
 
@@ -11,6 +11,8 @@ const mapVars = composeMapVars(resolveVarName);
 
 export const composeMockMutation = (getRecords, mapVars) =>
   (db, options = {}, _, vars, __, { fieldName, returnType }) => {
+    returnType = unwrapNonNull(returnType);
+
     let { mutations = {}, varsMap = {} } = options;
     let mutation = mutations[fieldName];
     let records = getRecords(db, returnType.name);

tests/dummy/app/gql/schema.graphql

@@ -29,7 +29,7 @@ type LineItemEdge {
 }
 
 type Mutation {
-  updatePerson(id: ID!, personAttributes: PersonAttributes!): Person
+  updatePerson(id: ID!, personAttributes: PersonAttributes!): Person!
 }
 
 interface Node {