Step 8.2: Resolve queries in relation to current user

context.ts

@@ -1,5 +1,7 @@
 import { PubSub } from 'apollo-server-express';
+import { User } from './db';
 
 export type MyContext = {
   pubsub: PubSub;
+  currentUser: User;
 };

index.ts

@@ -3,6 +3,7 @@ import bodyParser from 'body-parser';
 import cors from 'cors';
 import express from 'express';
 import http from 'http';
+import { users } from './db';
 import schema from './schema';
 
 const app = express();
@@ -17,7 +18,10 @@ app.get('/_ping', (req, res) => {
 const pubsub = new PubSub();
 const server = new ApolloServer({
   schema,
-  context: () => ({ pubsub }),
+  context: () => ({
+    currentUser: users.find(u => u.id === '1'),
+    pubsub,
+  }),
 });
 
 server.applyMiddleware({

schema/resolvers.ts

@@ -17,17 +17,35 @@ const resolvers: Resolvers = {
     recipient(message) {
       return users.find(u => u.id === message.recipient) || null;
     },
+
+    isMine(message, args, { currentUser }) {
+      return message.sender === currentUser.id;
+    },
   },
 
   Chat: {
-    name() {
-      // TODO: Resolve in relation to current user
-      return null;
+    name(chat, args, { currentUser }) {
+      if (!currentUser) return null;
+
+      const participantId = chat.participants.find(p => p !== currentUser.id);
+
+      if (!participantId) return null;
+
+      const participant = users.find(u => u.id === participantId);
+
+      return participant ? participant.name : null;
     },
 
-    picture() {
-      // TODO: Resolve in relation to current user
-      return null;
+    picture(chat, args, { currentUser }) {
+      if (!currentUser) return null;
+
+      const participantId = chat.participants.find(p => p !== currentUser.id);
+
+      if (!participantId) return null;
+
+      const participant = users.find(u => u.id === participantId);
+
+      return participant ? participant.picture : null;
     },
 
     messages(chat) {
@@ -48,29 +66,42 @@ const resolvers: Resolvers = {
   },
 
   Query: {
-    chats() {
-      return chats;
+    chats(root, args, { currentUser }) {
+      if (!currentUser) return [];
+
+      return chats.filter(c => c.participants.includes(currentUser.id));
     },
 
-    chat(root, { chatId }) {
-      return chats.find(c => c.id === chatId) || null;
+    chat(root, { chatId }, { currentUser }) {
+      if (!currentUser) return null;
+
+      const chat = chats.find(c => c.id === chatId);
+
+      if (!chat) return null;
+
+      return chat.participants.includes(currentUser.id) ? chat : null;
     },
   },
 
   Mutation: {
-    addMessage(root, { chatId, content }, { pubsub }) {
+    addMessage(root, { chatId, content }, { currentUser, pubsub }) {
+      if (!currentUser) return null;
+
       const chatIndex = chats.findIndex(c => c.id === chatId);
 
       if (chatIndex === -1) return null;
 
       const chat = chats[chatIndex];
+
+      if (!chat.participants.includes(currentUser.id)) return null;
+
       const recentMessage = messages[messages.length - 1];
       const messageId = String(Number(recentMessage.id) + 1);
       const message: Message = {
         id: messageId,
         createdAt: new Date(),
-        sender: '', // TODO: Fill-in
-        recipient: '', // TODO: Fill-in
+        sender: currentUser.id,
+        recipient: chat.participants.find(p => p !== currentUser.id) as string,
         content,
       };
 

tests/mutations/addMessage.test.ts

@@ -1,15 +1,18 @@
 import { createTestClient } from 'apollo-server-testing';
 import { ApolloServer, PubSub, gql } from 'apollo-server-express';
 import schema from '../../schema';
-import { resetDb } from '../../db';
+import { resetDb, users } from '../../db';
 
 describe('Mutation.addMessage', () => {
   beforeEach(resetDb);
 
   it('should add message to specified chat', async () => {
     const server = new ApolloServer({
       schema,
-      context: () => ({ pubsub: new PubSub() }),
+      context: () => ({
+        pubsub: new PubSub(),
+        currentUser: users[0],
+      }),
     });
 
     const { query, mutate } = createTestClient(server);

tests/queries/getChat.test.ts

@@ -1,10 +1,16 @@
 import { createTestClient } from 'apollo-server-testing';
 import { ApolloServer, gql } from 'apollo-server-express';
 import schema from '../../schema';
+import { users } from '../../db';
 
 describe('Query.chat', () => {
   it('should fetch specified chat', async () => {
-    const server = new ApolloServer({ schema });
+    const server = new ApolloServer({
+      schema,
+      context: () => ({
+        currentUser: users[0],
+      }),
+    });
 
     const { query } = createTestClient(server);
 

tests/queries/getChats.test.ts

@@ -1,10 +1,16 @@
 import { createTestClient } from 'apollo-server-testing';
 import { ApolloServer, gql } from 'apollo-server-express';
 import schema from '../../schema';
+import { users } from '../../db';
 
 describe('Query.chats', () => {
   it('should fetch all chats', async () => {
-    const server = new ApolloServer({ schema });
+    const server = new ApolloServer({
+      schema,
+      context: () => ({
+        currentUser: users[0],
+      }),
+    });
 
     const { query } = createTestClient(server);