fix(transforms): support custom scalar input variables on root fields…

… when transforming.

Fixes #18.

src/stitching/resolvers.ts

@@ -111,7 +111,7 @@ function createProxyingResolver(
     schema: schema as GraphQLSchema,
     operation,
     fieldName,
-    args: {},
+    args,
     context,
     info,
     transforms,

src/test/testTransforms.ts

@@ -4,6 +4,7 @@ import { expect } from 'chai';
 import {
   GraphQLSchema,
   GraphQLNamedType,
+  GraphQLScalarType,
   graphql,
   Kind,
   SelectionSetNode,
@@ -28,6 +29,71 @@ import {
 } from '../transforms';
 
 describe('transforms', () => {
+  describe('base transform function', () => {
+    let schema: GraphQLSchema;
+    let scalarTest = `
+      scalar TestScalar
+      type TestingScalar {
+        value: TestScalar
+      }
+
+      type Query {
+        testingScalar(input: TestScalar): TestingScalar
+      }
+    `;
+
+    let scalarSchema: GraphQLSchema;
+
+    scalarSchema = makeExecutableSchema({
+      typeDefs: scalarTest,
+      resolvers: {
+        TestScalar: new GraphQLScalarType({
+          name: 'TestScalar',
+          description: undefined,
+          serialize: value => (value as string).slice(1),
+          parseValue: value => `_${value}`,
+          parseLiteral: (ast: any) => `_${ast.value}`,
+        }),
+        Query: {
+          testingScalar(parent, args) {
+            return {
+              value: args.input[0] === '_' ? args.input : null
+            };
+          },
+        },
+      },
+    });
+
+    before(() => {
+      schema = transformSchema(scalarSchema, []);
+    });
+    it('should work', async () => {
+      const result = await graphql(
+        schema,
+        `
+          query($input: TestScalar) {
+            testingScalar(input: $input) {
+              value
+            }
+          }
+        `,
+        {},
+        {},
+        {
+          input: 'test',
+        },
+      );
+
+      expect(result).to.deep.equal({
+        data: {
+          testingScalar: {
+            value: 'test',
+          },
+        },
+      });
+    });
+  });
+
   describe('rename type', () => {
     let schema: GraphQLSchema;
     before(() => {