refactor: Use graphql schema directly with graphql-tools library

packages/backend/src/graphql/mutations/delete-step.ts

@@ -1,16 +1,15 @@
-import { GraphQLString, GraphQLNonNull } from 'graphql';
-import RequestWithCurrentUser from '../../types/express/request-with-current-user';
-import stepType from '../types/step';
+import Context from '../../types/express/context';
 
 type Params = {
   id: string;
 };
 
-const deleteStepResolver = async (
+const deleteStep = async (
+  _parent: unknown,
   params: Params,
-  req: RequestWithCurrentUser
+  context: Context
 ) => {
-  const step = await req.currentUser
+  const step = await context.currentUser
     .$relatedQuery('steps')
     .withGraphFetched('flow')
     .findOne({
@@ -40,13 +39,4 @@ const deleteStepResolver = async (
   return step;
 };
 
-const deleteStep = {
-  type: stepType,
-  args: {
-    id: { type: GraphQLNonNull(GraphQLString) },
-  },
-  resolve: (_: any, params: Params, req: RequestWithCurrentUser) =>
-    deleteStepResolver(params, req),
-};
-
 export default deleteStep;