tests: add introspection query loading test

Author: stephen

src/__tests__/introspection-query/.graphqlconfig

@@ -0,0 +1,3 @@
+{
+  "schemaPath": "./schema.json"
+}

src/__tests__/introspection-query/getSchema.ts

@@ -0,0 +1,33 @@
+import test from 'ava'
+import { join } from 'path'
+import { printSchema } from 'graphql'
+const schema = require('../schema.json')
+import { getGraphQLConfig, GraphQLConfig } from '../../'
+
+test('reads single schema', t => {
+  const config = getGraphQLConfig(__dirname)
+
+  const typeDefs = `\
+schema {
+  query: RootQueryType
+}
+
+type Bar {
+  widgets: [Widget]
+}
+
+type RootQueryType {
+  foo: String
+  bar: Bar
+}
+
+type Widget {
+  count: Int
+}
+`
+
+  t.is(
+    printSchema(config.getProjectConfig('testSchemaA').getSchema()),
+    typeDefs,
+  )
+})