From f7291d105e1d605df93ab61bb0048458bffedab5 Mon Sep 17 00:00:00 2001
From: Simon Knott <info@simonknott.de>
Date: Wed, 5 Jul 2023 11:05:08 +0200
Subject: [PATCH] EF: Don't crash CLI when uncompressed request throws uncaught
 exception  (#5837)

* chore: add test

* fix: add content negotiation to error decoding
---
 src/utils/proxy.mjs                        | 24 +++++++++++++++--
 tests/integration/100.command.dev.test.cjs | 30 ++++++++++++++++++++++
 2 files changed, 52 insertions(+), 2 deletions(-)

diff --git a/src/utils/proxy.mjs b/src/utils/proxy.mjs
index 6bed105aa62..1c52551511b 100644
--- a/src/utils/proxy.mjs
+++ b/src/utils/proxy.mjs
@@ -36,9 +36,29 @@ import { generateRequestID } from './request-id.mjs'
 import { createRewriter, onChanges } from './rules-proxy.mjs'
 import { signRedirect } from './sign-redirect.mjs'
 
-const decompress = util.promisify(zlib.gunzip)
+const gunzip = util.promisify(zlib.gunzip)
+const brotliDecompress = util.promisify(zlib.brotliDecompress)
+const deflate = util.promisify(zlib.deflate)
 const shouldGenerateETag = Symbol('Internal: response should generate ETag')
 
+/**
+ * @param {Buffer} body
+ * @param {string | undefined} contentEncoding
+ * @returns {Promise<Buffer>}
+ */
+const decompressResponseBody = async function (body, contentEncoding = '') {
+  switch (contentEncoding) {
+    case 'gzip':
+      return await gunzip(body)
+    case 'br':
+      return await brotliDecompress(body)
+    case 'deflate':
+      return await deflate(body)
+    default:
+      return body
+  }
+}
+
 const formatEdgeFunctionError = (errorBuffer, acceptsHtml) => {
   const {
     error: { message, name, stack },
@@ -479,7 +499,7 @@ const initializeProxy = async function ({ configPath, distDir, env, host, port,
 
       if (isEdgeFunctionsRequest(req) && isUncaughtError) {
         const acceptsHtml = req.headers && req.headers.accept && req.headers.accept.includes('text/html')
-        const decompressedBody = await decompress(responseBody)
+        const decompressedBody = await decompressResponseBody(responseBody, req.headers['content-encoding'])
         const formattedBody = formatEdgeFunctionError(decompressedBody, acceptsHtml)
         const errorResponse = acceptsHtml
           ? await renderErrorTemplate(formattedBody, './templates/function-error.html', 'edge function')
diff --git a/tests/integration/100.command.dev.test.cjs b/tests/integration/100.command.dev.test.cjs
index f70e5873415..0752c829039 100644
--- a/tests/integration/100.command.dev.test.cjs
+++ b/tests/integration/100.command.dev.test.cjs
@@ -553,6 +553,36 @@ test('When an edge function fails, serves a fallback defined by its `on_error` m
   })
 })
 
+test('When an edge function throws uncaught exception, the dev server continues working', async (t) => {
+  await withSiteBuilder('site-with-edge-function-uncaught-exception', async (builder) => {
+    builder
+      .withNetlifyToml({
+        config: {
+          build: {
+            edge_functions: 'netlify/edge-functions',
+          },
+        },
+      })
+      .withEdgeFunction({
+        config: { path: '/hello' },
+        handler: () => {
+          const url = new URL('/shouldve-provided-a-base')
+          return new Response(url.toString())
+        },
+        name: 'hello-1',
+      })
+
+    await builder.buildAsync()
+
+    await withDevServer({ cwd: builder.directory }, async (server) => {
+      const response1 = await got(`${server.url}/hello`, {
+        decompress: false,
+      })
+      t.is(response1.statusCode, 200)
+    })
+  })
+})
+
 test('redirect with country cookie', async (t) => {
   await withSiteBuilder('site-with-country-cookie', async (builder) => {
     builder