From 1b26dec38cba698d0bddd2c9881fdd344a0de48a Mon Sep 17 00:00:00 2001
From: DAB0mB <emanor6@gmail.com>
Date: Tue, 9 Apr 2019 14:53:20 +0800
Subject: [PATCH] Step 9.5: Add Subscription.chatRemoved

---
 schema/resolvers.ts     | 18 +++++++++++++++++-
 schema/typeDefs.graphql |  1 +
 2 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/schema/resolvers.ts b/schema/resolvers.ts
index 8863ad607..8e198e94a 100644
--- a/schema/resolvers.ts
+++ b/schema/resolvers.ts
@@ -160,7 +160,7 @@ const resolvers: Resolvers = {
       return chat;
     },
 
-    removeChat(root, { chatId }, { currentUser }) {
+    removeChat(root, { chatId }, { currentUser, pubsub }) {
       if (!currentUser) return null;
 
       const chatIndex = chats.findIndex(c => c.id === chatId);
@@ -181,6 +181,11 @@ const resolvers: Resolvers = {
 
       chats.splice(chatIndex, 1);
 
+      pubsub.publish('chatRemoved', {
+        chatRemoved: chat.id,
+        targetChat: chat,
+      });
+
       return chatId;
     },
   },
@@ -209,6 +214,17 @@ const resolvers: Resolvers = {
         }
       ),
     },
+
+    chatRemoved: {
+      subscribe: withFilter(
+        (root, args, { pubsub }) => pubsub.asyncIterator('chatRemoved'),
+        ({ targetChat }: { targetChat: Chat }, args, { currentUser }) => {
+          if (!currentUser) return false;
+
+          return targetChat.participants.some(p => p === currentUser.id);
+        }
+      ),
+    },
   },
 };
 
diff --git a/schema/typeDefs.graphql b/schema/typeDefs.graphql
index 7f5e2c848..bf0ba2d5e 100644
--- a/schema/typeDefs.graphql
+++ b/schema/typeDefs.graphql
@@ -41,4 +41,5 @@ type Mutation {
 type Subscription {
   messageAdded: Message!
   chatAdded: Chat!
+  chatRemoved: ID!
 }