From 00179adcaa3140f74786d4cd07c0adc7ad6ae01d Mon Sep 17 00:00:00 2001
From: Joe Haddad <timer150@gmail.com>
Date: Thu, 2 Jan 2020 18:47:39 -0500
Subject: [PATCH] Fix User Error in Async API Endpoint (#9911)

---
 packages/next/next-server/server/api-utils.ts              | 2 +-
 test/integration/api-support/pages/api/user-error-async.js | 3 +++
 test/integration/api-support/test/index.test.js            | 7 +++++++
 3 files changed, 11 insertions(+), 1 deletion(-)
 create mode 100644 test/integration/api-support/pages/api/user-error-async.js

diff --git a/packages/next/next-server/server/api-utils.ts b/packages/next/next-server/server/api-utils.ts
index e9f7b1911b..8e200b2ec8 100644
--- a/packages/next/next-server/server/api-utils.ts
+++ b/packages/next/next-server/server/api-utils.ts
@@ -54,7 +54,7 @@ export async function apiResolver(
     apiRes.json = data => sendJson(apiRes, data)
 
     const resolver = interopDefault(resolverModule)
-    resolver(req, res)
+    await resolver(req, res)
   } catch (err) {
     if (err instanceof ApiError) {
       sendError(apiRes, err.statusCode, err.message)
diff --git a/test/integration/api-support/pages/api/user-error-async.js b/test/integration/api-support/pages/api/user-error-async.js
new file mode 100644
index 0000000000..06214200c2
--- /dev/null
+++ b/test/integration/api-support/pages/api/user-error-async.js
@@ -0,0 +1,3 @@
+export default async (req, res) => {
+  throw new Error('User error')
+}
diff --git a/test/integration/api-support/test/index.test.js b/test/integration/api-support/test/index.test.js
index 115c965dd7..b422a4a35a 100644
--- a/test/integration/api-support/test/index.test.js
+++ b/test/integration/api-support/test/index.test.js
@@ -63,6 +63,13 @@ function runTests(dev = false) {
     expect(text).toBe('Internal Server Error')
   })
 
+  it('should throw Internal Server Error (async)', async () => {
+    const res = await fetchViaHTTP(appPort, '/api/user-error-async', null, {})
+    const text = await res.text()
+    expect(res.status).toBe(500)
+    expect(text).toBe('Internal Server Error')
+  })
+
   it('should parse JSON body', async () => {
     const data = await fetchViaHTTP(appPort, '/api/parse', null, {
       method: 'POST',