fix: create server handler in sequential steps (#373)

* test: repro EEXIST

* fix: create server handler in sequential steps

Author: pieh

src/build/functions/server.ts

@@ -115,15 +115,13 @@ export const createServerHandler = async (ctx: PluginContext) => {
     await rm(ctx.serverFunctionsDir, { recursive: true, force: true })
     await mkdir(join(ctx.serverHandlerDir, '.netlify'), { recursive: true })
 
-    await Promise.all([
-      copyNextServerCode(ctx),
-      copyNextDependencies(ctx),
-      writeTagsManifest(ctx),
-      copyHandlerDependencies(ctx),
-      writeHandlerManifest(ctx),
-      writePackageMetadata(ctx),
-      writeHandlerFile(ctx),
-    ])
+    await copyNextServerCode(ctx)
+    await copyNextDependencies(ctx)
+    await writeTagsManifest(ctx)
+    await copyHandlerDependencies(ctx)
+    await writeHandlerManifest(ctx)
+    await writePackageMetadata(ctx)
+    await writeHandlerFile(ctx)
 
     await verifyHandlerDirStructure(ctx)
   })

tests/fixtures/simple-next-app/netlify.toml

@@ -1,3 +1,17 @@
 [functions]
 directory = "netlify/functions"
-included_files = ["static/**"]
+included_files = [
+  "static/**",
+  # this is setup for testing regressions on EEXIST error:
+  # next.config.js -> experimental.outputFileTracingIncludes makes next.js
+  # to add those files to .next/standalone directory and we again add those
+  # files to server handler with this configuration and this makes sure
+  # there is no errors happening
+  "public/**",
+  # this is setup for testing regressions on EEXIST error:
+  # next.js will output node_modules by default to .next/standalone
+  # this makes sure we test scenario when we additionally copy extra files
+  # to shared directory and make sure it's not causing EEXIST errors
+  # added package is not being outputted by next.js by default
+  "node_modules/js-tokens/**",
+]

tests/fixtures/simple-next-app/next.config.js

@@ -4,6 +4,11 @@ const nextConfig = {
   eslint: {
     ignoreDuringBuilds: true,
   },
+  experimental: {
+    outputFileTracingIncludes: {
+      '/': ['public/**'],
+    },
+  },
   images: {
     remotePatterns: [
       {