fix: call middlewares defined after koaMiddleware

src/__tests__/koa.test.ts

@@ -1,5 +1,6 @@
 import { ApolloServer } from '@apollo/server';
 import koa from 'koa';
+import bodyParser from 'koa-bodyparser';
 import request from 'supertest';
 import { it, expect } from '@jest/globals';
 import { koaMiddleware } from '..';
@@ -19,6 +20,25 @@ it('gives helpful error if body-parser middleware is not installed', async () =>
   await server.stop();
 });
 
+it('calls middlewares defined after it', async () => {
+  const server = new ApolloServer({ typeDefs: 'type Query {f: ID}' });
+  const app = new koa();
+  const spy = jest.fn();
+
+  await server.start();
+
+  app.use(bodyParser());
+  app.use(koaMiddleware(server));
+  app.use((_, next) => {
+    spy();
+    return next();
+  });
+
+  await request(app.callback()).post('/').send({ query: '{f}' }).expect(200);
+  expect(spy).toBeCalled();
+  await server.stop();
+});
+
 it('not calling start causes a clear error', async () => {
   const server = new ApolloServer({ typeDefs: 'type Query {f: ID}' });
   expect(() => koaMiddleware(server)).toThrow(

src/index.ts

@@ -69,7 +69,7 @@ export function koaMiddleware<
     TContext
   > = options?.context ?? defaultContext;
 
-  return async (ctx) => {
+  return async (ctx, next) => {
     if (!ctx.request.body) {
       // The json koa-bodyparser *always* sets ctx.request.body to {} if it's unset (even
       // if the Content-Type doesn't match), so if it isn't set, you probably
@@ -136,5 +136,7 @@ export function koaMiddleware<
     for (const [key, value] of headers) {
       ctx.set(key, value);
     }
+
+    return next();
   };
 }