From 40767e5ce7b2581d462d8f74a1d9433496dd553e Mon Sep 17 00:00:00 2001
From: Sukka <isukkaw@gmail.com>
Date: Thu, 1 Sep 2022 07:08:56 +0800
Subject: [PATCH] fix(#40066): preserve error status code from serveStatic
 (#40128)

The PR fixes #40066.

Next.js' `serveStatic` method is powered by the [send](https://github.com/pillarjs/send) module, which could throw errors under specific circumstances.
Currently, Next.js only preserves the 412 Error from send, hence issue #40066 (where 416 Error is not preserved).

## Bug

- [x] Related issues linked using `fixes #number`
- [x] Integration tests added
- [ ] Errors have helpful link attached, see `contributing.md`
---
 packages/next/server/next-server.ts           | 42 ++++++++++++++++++-
 .../file-serving/test/index.test.js           | 10 +++++
 2 files changed, 50 insertions(+), 2 deletions(-)

diff --git a/packages/next/server/next-server.ts b/packages/next/server/next-server.ts
index dca746ea6b301e6..48f19bf2e47401c 100644
--- a/packages/next/server/next-server.ts
+++ b/packages/next/server/next-server.ts
@@ -153,6 +153,41 @@ function getMiddlewareMatcher(
   return matcher
 }
 
+/**
+ * Hardcoded every possible error status code that could be thrown by "serveStatic" method
+ * This is done by searching "this.error" inside "send" module's source code:
+ * https://github.com/pillarjs/send/blob/master/index.js
+ * https://github.com/pillarjs/send/blob/develop/index.js
+ */
+const POSSIBLE_ERROR_CODE_FROM_SERVE_STATIC = new Set([
+  // send module will throw 500 when header is already sent or fs.stat error happens
+  // https://github.com/pillarjs/send/blob/53f0ab476145670a9bdd3dc722ab2fdc8d358fc6/index.js#L392
+  // Note: we will use Next.js built-in 500 page to handle 500 errors
+  // 500,
+
+  // send module will throw 404 when file is missing
+  // https://github.com/pillarjs/send/blob/53f0ab476145670a9bdd3dc722ab2fdc8d358fc6/index.js#L421
+  // Note: we will use Next.js built-in 404 page to handle 404 errors
+  // 404,
+
+  // send module will throw 403 when redirecting to a directory without enabling directory listing
+  // https://github.com/pillarjs/send/blob/53f0ab476145670a9bdd3dc722ab2fdc8d358fc6/index.js#L484
+  // Note: Next.js throws a different error (without status code) for directory listing
+  // 403,
+
+  // send module will throw 400 when fails to normalize the path
+  // https://github.com/pillarjs/send/blob/53f0ab476145670a9bdd3dc722ab2fdc8d358fc6/index.js#L520
+  400,
+
+  // send module will throw 412 with conditional GET request
+  // https://github.com/pillarjs/send/blob/53f0ab476145670a9bdd3dc722ab2fdc8d358fc6/index.js#L632
+  412,
+
+  // send module will throw 416 when range is not satisfiable
+  // https://github.com/pillarjs/send/blob/53f0ab476145670a9bdd3dc722ab2fdc8d358fc6/index.js#L669
+  416,
+])
+
 function getEdgeMatcher(
   info: MiddlewareManifest['functions'][string]
 ): RouteMatch {
@@ -1362,8 +1397,11 @@ export default class NextNodeServer extends BaseServer {
       const err = error as Error & { code?: string; statusCode?: number }
       if (err.code === 'ENOENT' || err.statusCode === 404) {
         this.render404(req, res, parsedUrl)
-      } else if (err.statusCode === 412) {
-        res.statusCode = 412
+      } else if (
+        typeof err.statusCode === 'number' &&
+        POSSIBLE_ERROR_CODE_FROM_SERVE_STATIC.has(err.statusCode)
+      ) {
+        res.statusCode = err.statusCode
         return this.renderError(err, req, res, path)
       } else {
         throw err
diff --git a/test/integration/file-serving/test/index.test.js b/test/integration/file-serving/test/index.test.js
index cb886b6fd2387a1..7b09bb29cc63df0 100644
--- a/test/integration/file-serving/test/index.test.js
+++ b/test/integration/file-serving/test/index.test.js
@@ -68,6 +68,16 @@ const runTests = () => {
     expect(res.headers.get('content-type')).toBe('image/avif')
   })
 
+  it('should serve correct error code', async () => {
+    // vercel-icon-dark.avif is downloaded from https://vercel.com/design and transformed to avif on avif.io
+    const res = await fetchViaHTTP(appPort, '/vercel-icon-dark.avif', '', {
+      headers: {
+        Range: 'bytes=1000000000-',
+      },
+    })
+    expect(res.status).toBe(416) // 416 Range Not Satisfiable
+  })
+
   // checks against traversal requests from
   // https://github.com/swisskyrepo/PayloadsAllTheThings/blob/master/Directory%20Traversal/Intruder/traversals-8-deep-exotic-encoding.txt