Add createdAt field

Author: murajun1978

functions/src/graphql/resolvers/Mutation.ts

@@ -3,7 +3,7 @@ export const Mutation = {
     const { body } = args.input;
     return await firestore
       .collection("messages")
-      .add({ body })
+      .add({ body, createdAt: Date.now() })
       .then(async ref => {
         const snapShot = await firestore
           .collection("messages")

functions/src/graphql/resolvers/Query.ts

@@ -1,6 +1,9 @@
 export const Query = {
   messages: async (parent, args, { firestore }) => {
-    const snapShot = await firestore.collection("messages").get();
+    const snapShot = await firestore
+      .collection("messages")
+      .orderBy("createdAt")
+      .get();
     return snapShot.docs.map(doc => ({ id: doc.id, ...doc.data() }));
   }
 };

functions/src/graphql/server.ts

@@ -3,6 +3,8 @@ import { resolvers } from "./resolvers";
 import { firestore } from "./utils";
 
 const typeDefs = `
+  scalar DateTime
+
   type Query {
     hello(name: String): String!
     messages: [Message!]!
@@ -15,6 +17,7 @@ const typeDefs = `
   type Message {
     id: String!
     body: String!
+    createdAt: DateTime!
   }
 
   input AddMessageInput {