feat(create): adds type

src/create/index.ts

@@ -3,3 +3,4 @@ export * from './service';
 export * from './services';
 export * from './schema';
 export * from './scope';
+export * from './type';

src/create/type.ts

@@ -0,0 +1,31 @@
+import {
+  CollectionTree,
+  InputRequest,
+  InputResponse,
+  InputError
+} from '~/types';
+import { collection } from './collection';
+
+export function error(name: string, type: InputError): CollectionTree {
+  const tree = collection();
+  tree.types.error[name] = type;
+  return tree;
+}
+
+export function request(name: string, type: InputRequest): CollectionTree {
+  const tree = collection();
+  tree.types.request[name] = type;
+  return tree;
+}
+
+export function response(name: string, type: InputResponse): CollectionTree {
+  const tree = collection();
+  tree.types.response[name] = {
+    ...type,
+    children: {
+      query: (type.children && type.children.query) || {},
+      subscription: (type.children && type.children.subscription) || {}
+    }
+  };
+  return tree;
+}