test: add subscription test

package.json

@@ -59,7 +59,8 @@
     "supertest": "^6.1.3",
     "ts-node": "^9.1.1",
     "typescript": "^4.2.4",
-    "uvu": "^0.5.1"
+    "uvu": "^0.5.1",
+    "ws": "^7.4.6"
   },
   "dependencies": {
     "@nestjs/graphql": "~7.10.6"

tests/code-first/app.module.ts

@@ -13,6 +13,7 @@ import { UpperCaseDirective } from '../example/directives/upper-case.directive';
       schemaDirectives: {
         uppercase: UpperCaseDirective,
       },
+      subscription: true,
     }),
   ],
   providers: [CatService, DogService, AnimalResolver, CatResolver],

tests/code-first/resolvers/cat.resolver.ts

@@ -1,8 +1,17 @@
-import { Args, ID, Parent, Query, Resolver } from '@nestjs/graphql';
+import {
+  Args,
+  Context,
+  ID,
+  Parent,
+  Query,
+  Resolver,
+  Subscription,
+} from '@nestjs/graphql';
 import { Cat } from '../types/cat';
 import { CatService } from '../services/cat.service';
 import { ParseIntPipe } from '@nestjs/common';
-import { LoaderQuery, ResolveLoader } from '../../../lib';
+import { LoaderQuery, ResolveLoader, toAsyncIterator } from '../../../lib';
+import { PubSub } from 'mercurius';
 
 @Resolver(() => Cat)
 export class CatResolver {
@@ -22,4 +31,11 @@ export class CatResolver {
   hasFur(@Parent() queries: LoaderQuery<Cat>[]) {
     return queries.map(({ obj }) => obj.lives > 1);
   }
+
+  @Subscription(() => Cat, {
+    resolve: (payload) => payload,
+  })
+  onCatSub(@Context('pubsub') pubSub: PubSub) {
+    return toAsyncIterator(pubSub.subscribe('CAT_SUB_TOPIC'));
+  }
 }

tests/e2e/code-first.spec.ts

@@ -7,6 +7,9 @@ import { suite } from 'uvu';
 import * as assert from 'uvu/assert';
 import { Test } from '@nestjs/testing';
 import { AppModule } from '../code-first/app.module';
+import * as Websocket from 'ws';
+import { FastifyInstance } from 'fastify';
+import { cats } from '../code-first/services/cat.service';
 
 interface Context {
   app: NestFastifyApplication;
@@ -262,4 +265,72 @@ gqlSuite(
   },
 );
 
+gqlSuite('subscriber should work', async ({ app }) => {
+  return new Promise<void>((resolve, reject) => {
+    app.listen(0, (err) => {
+      if (err) {
+        return reject(err);
+      }
+      const port = app.getHttpServer().address().port;
+      const fastifyApp = app.getHttpAdapter().getInstance() as FastifyInstance;
+
+      const ws = new Websocket(`ws://localhost:${port}/graphql`, 'graphql-ws');
+
+      const client = Websocket.createWebSocketStream(ws, {
+        encoding: 'utf8',
+        objectMode: true,
+      });
+      client.setEncoding('utf8');
+      client.write(
+        JSON.stringify({
+          type: 'connection_init',
+        }),
+      );
+
+      client.write(
+        JSON.stringify({
+          id: 1,
+          type: 'start',
+          payload: {
+            query: `
+          subscription {
+            onCatSub {
+              id
+              lives
+              name
+              hasFur
+            }
+          }
+        `,
+          },
+        }),
+      );
+
+      client.on('data', (chunk) => {
+        const data = JSON.parse(chunk);
+
+        if (data.type === 'connection_ack') {
+          fastifyApp.graphql.pubsub.publish({
+            topic: 'CAT_SUB_TOPIC',
+            payload: cats[0],
+          });
+        } else if (data.id === 1) {
+          const expectedCat = expectedCats[0];
+          const receivedCat = data.payload.data?.onCatSub;
+          assert.ok(receivedCat);
+          assert.equal(expectedCat.id, receivedCat.id);
+          assert.type(receivedCat.hasFur, 'boolean');
+
+          client.end();
+        }
+      });
+
+      client.on('end', () => {
+        client.destroy();
+        app.close().then(resolve).catch(reject);
+      });
+    });
+  });
+});
+
 gqlSuite.run();

yarn.lock

@@ -6487,6 +6487,11 @@ ws@^7.4.2, ws@^7.4.3:
   resolved "https://registry.yarnpkg.com/ws/-/ws-7.4.5.tgz#a484dd851e9beb6fdb420027e3885e8ce48986c1"
   integrity sha512-xzyu3hFvomRfXKH8vOFMU3OguG6oOvhXMo3xsGy3xWExqaM2dxBbVxuD99O7m3ZUFMvvscsZDqxfgMaRr/Nr1g==
 
+ws@^7.4.6:
+  version "7.4.6"
+  resolved "https://registry.yarnpkg.com/ws/-/ws-7.4.6.tgz#5654ca8ecdeee47c33a9a4bf6d28e2be2980377c"
+  integrity sha512-YmhHDO4MzaDLB+M9ym/mDA5z0naX8j7SIlT8f8z+I0VtzsRbekxEutHSme7NPS2qE8StCYQNUnfWdXta/Yu85A==
+
 xdg-basedir@^4.0.0:
   version "4.0.0"
   resolved "https://registry.yarnpkg.com/xdg-basedir/-/xdg-basedir-4.0.0.tgz#4bc8d9984403696225ef83a1573cbbcb4e79db13"