variable type hover test

Author: acao

packages/graphql-language-service/src/interface/__tests__/getHoverInformation-test.ts

@@ -101,6 +101,14 @@ describe('getHoverInformation', () => {
     expect(actual).toEqual('Query.parameterizedField(id: String!)');
   });
 
+  it('provides variable type information', () => {
+    const actual = testHover(
+      'query($who: String!) { parameterizedField(id: $who) { testField } }',
+      new Position(0, 48),
+    );
+    expect(actual).toEqual('String!');
+  });
+
   it('provides directive information', () => {
     const actual = testHover(
       'query { thing { testField @skip(if:true) } }',