feat: Implement get flow graphQL query

packages/backend/src/graphql/queries/get-flow.ts

@@ -0,0 +1,29 @@
+import { GraphQLNonNull, GraphQLString } from 'graphql';
+import Flow from '../../models/flow';
+import RequestWithCurrentUser from '../../types/express/request-with-current-user';
+import flowType from '../types/flow';
+
+type Params = {
+  id: number
+}
+
+const getFlowResolver = async (params: Params, req: RequestWithCurrentUser) => {
+  const flowParams = { user_id: req.currentUser.id, id: params.id }
+
+  const flow = await Flow.query()
+    .withGraphFetched('steps')
+    .findOne(flowParams)
+    .throwIfNotFound();
+
+  return flow;
+}
+
+const getFlow = {
+  type: flowType,
+  args: {
+    id: { type: GraphQLNonNull(GraphQLString) },
+  },
+  resolve: (_: any, params: Params, req: RequestWithCurrentUser) => getFlowResolver(params, req)
+}
+
+export default getFlow;