fix: better error handling for next server imports

Author: ascorbic

src/templates/getHandler.js

@@ -7,26 +7,33 @@ const makeHandler =
   () =>
   // We return a function and then call `toString()` on it to serialise it as the launcher function
   (conf, app) => {
+    // This is just so nft knows about the page entrypoints
+    try {
+      // eslint-disable-next-line node/no-missing-require
+      require.resolve('./pages.js')
+    } catch {}
+
     let NextServer
     try {
       // next >= 11.0.1. Yay breaking changes in patch releases!
       NextServer = require('next/dist/server/next-server').default
-    } catch {
+    } catch (error) {
+      if (!error.message.includes("Cannot find module 'next/dist/server/next-server'")) {
+        // A different error, so rethrow it
+        throw error
+      }
       // Probably an old version of next
     }
 
-    // This is just so nft knows about the page entrypoints
-    try {
-      // eslint-disable-next-line node/no-missing-require
-      require.resolve('./pages.js')
-    } catch {}
-
     if (!NextServer) {
       try {
         // next < 11.0.1
         // eslint-disable-next-line node/no-missing-require, import/no-unresolved
         NextServer = require('next/dist/next-server/server/next-server').default
-      } catch {
+      } catch (error) {
+        if (!error.message.includes("Cannot find module 'next/dist/server/next-server'")) {
+          throw error
+        }
         throw new Error('Could not find Next.js server')
       }
     }
@@ -66,11 +73,7 @@ const makeHandler =
         }
       }
 
-      if (
-        multiValueHeaders['set-cookie'] &&
-        multiValueHeaders['set-cookie'][0] &&
-        multiValueHeaders['set-cookie'][0].includes('__prerender_bypass')
-      ) {
+      if (multiValueHeaders['set-cookie']?.[0]?.includes('__prerender_bypass')) {
         delete multiValueHeaders.etag
         multiValueHeaders['cache-control'] = ['no-cache']
       }

test/index.js

@@ -42,7 +42,7 @@ const onBuildHasRun = (netlifyConfig) =>
 
 // Move .next from sample project to current directory
 const moveNextDist = async function () {
-  await stubModules(['next', 'react', 'react-dom', 'sharp'])
+  await stubModules(['next', 'sharp'])
   await copy(path.join(SAMPLE_PROJECT_DIR, '.next'), path.join(process.cwd(), '.next'))
 }