From f767ad81ceb90f7d0c3c2ffc5a6c1cce052b4e77 Mon Sep 17 00:00:00 2001
From: Enrico Ros <enrico.ros@gmail.com>
Date: Sat, 17 Feb 2024 18:03:21 -0800
Subject: [PATCH] Export Frontend: work around NextJS aborting on the nodejs
 API.

This introduces a pre-build step on Next Build, which hides the files
in the app/api directory when the EXPORT_FRONTEND environment
variable is true-ish.

Hopefully there won't be disruption due to the post-processing step.

Also check https://github.com/vercel/next.js/issues/61213 for
upstream updates.
---
 .gitignore           |  3 +++
 next.config.mjs      |  4 ++--
 package.json         |  1 +
 scripts/prebuild.mjs | 47 ++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 53 insertions(+), 2 deletions(-)
 create mode 100644 scripts/prebuild.mjs

diff --git a/.gitignore b/.gitignore
index e4038b126..6f40ade05 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,5 +1,8 @@
 # See https://help.github.com/articles/ignoring-files/ for more about ignoring files.
 
+# Frontend Build: ignore API files disabled for this build
+/app/**/*.backup
+
 # dependencies
 /node_modules
 /.pnp
diff --git a/next.config.mjs b/next.config.mjs
index 61974ca23..66f917b66 100644
--- a/next.config.mjs
+++ b/next.config.mjs
@@ -1,6 +1,6 @@
 const BuildOptions = {
   // Future: Electron/Frontend-only builds
-  exportFrontend: false,
+  exportFrontend: !!process.env.EXPORT_FRONTEND,
 };
 
 /** @type {import('next').NextConfig} */
@@ -11,7 +11,7 @@ let nextConfig = {
   ...BuildOptions.exportFrontend && {
     // Export the frontend to ./dist
     output: 'export',
-    distDir: 'dist',
+    distDir: 'out',
 
     // Disable Image optimization
     images: { unoptimized: true },
diff --git a/package.json b/package.json
index 8e5bb2d1a..3d27b8007 100644
--- a/package.json
+++ b/package.json
@@ -8,6 +8,7 @@
     "start": "next start",
     "lint": "next lint",
     "postinstall": "prisma generate",
+    "prebuild": "node scripts/prebuild.mjs",
     "db:push": "prisma db push",
     "db:studio": "prisma studio",
     "vercel:env:pull": "npx vercel env pull .env.development.local"
diff --git a/scripts/prebuild.mjs b/scripts/prebuild.mjs
new file mode 100644
index 000000000..c7c32ea39
--- /dev/null
+++ b/scripts/prebuild.mjs
@@ -0,0 +1,47 @@
+import { default as fs, renameSync } from 'fs';
+import { dirname as pathDirName, join as pathJoin } from 'path';
+import { fileURLToPath } from 'url';
+
+
+// build-time configuration
+const buildOnlyFrontend = !!process.env.EXPORT_FRONTEND;
+
+
+function getApiDirName() {
+  const __filename = fileURLToPath(import.meta.url);
+  const __dirname = pathDirName(__filename);
+  return pathJoin(__dirname, '../app/api');
+}
+
+function findAllFiles(startDir) {
+  return fs.readdirSync(startDir).flatMap((file) => {
+      const fullPath = pathJoin(startDir, file);
+      if (fs.statSync(fullPath).isDirectory())
+        return findAllFiles(fullPath);
+      return fullPath;
+    },
+  );
+}
+
+/**
+ * Hide/show API routes depending on the build type
+ * Due to an upstream bug, NextJS will not ignore the nodejs API routes and choose to abort instead.
+ */
+function prebuildFrontendHotFixes(hideFiles) {
+  const apiDirName = getApiDirName();
+  const apiRoutesPaths = findAllFiles(apiDirName)
+    .filter((path) => path.endsWith('.ts') || path.endsWith('.ts.backup'));
+
+  apiRoutesPaths.forEach((path) => {
+    const isBackup = path.endsWith('.backup');
+    if (hideFiles) {
+      // If building the frontend, rename (effectively hide) the file
+      !isBackup && renameSync(path, `${path}.backup`);
+    } else {
+      // If it's a normal build and including API routes and a backup exists, restore it
+      isBackup && renameSync(path, path.slice(0, -7));
+    }
+  });
+}
+
+prebuildFrontendHotFixes(buildOnlyFrontend);