fix(web): keep Vercel static builds writing to out (#2946)

* fix(web): keep Vercel static builds writing to out (#1628)

Generated-By: looper 0.9.1 (runner=worker, agent=opencode)

* fix(web): preserve explicit dist dir overrides

Generated-By: looper 0.9.1 (runner=fixer, agent=opencode)

* fix(web): preserve explicit dist dir overrides

Generated-By: looper 0.9.1 (runner=fixer, agent=opencode)

apps/web/next.config.ts

@@ -79,7 +79,9 @@ function resolveDistDir(defaultValue: string) {
   return toPosixPath(isAbsolute(configured) ? relative(WEB_ROOT, configured) || '.' : configured);
 }
 
-const DIST_DIR = resolveDistDir(isProd ? (shouldStaticExport ? 'out' : '.next') : '.next');
+const DIST_DIR = shouldStaticExport && !process.env.OD_WEB_DIST_DIR
+  ? null
+  : resolveDistDir('.next');
 
 function resolveDevTsconfigPath() {
   const configured = process.env.OD_WEB_TSCONFIG_PATH;
@@ -166,9 +168,10 @@ const nextConfig: NextConfig = {
     root: WORKSPACE_ROOT,
   },
   ...(DEV_TSCONFIG_PATH ? { typescript: { tsconfigPath: DEV_TSCONFIG_PATH } } : {}),
-  // Keep the bundle output predictable so the daemon's STATIC_DIR can point
+  // Static exports keep Next.js's default `out/` output directory so static
-  // at it without any glob trickery.
+  // hosts like Vercel can publish the generated site directly. Server runtimes
-  distDir: DIST_DIR,
+  // still keep a predictable traced build directory for sidecar launchers.
+  ...(DIST_DIR ? { distDir: DIST_DIR } : {}),
   ...(shouldStaticExport
     ? {
         output: 'export' as const,

apps/web/tests/runtime/app-route-export.test.ts

@@ -1,11 +1,45 @@
-import { describe, expect, it } from 'vitest';
+import { dirname, resolve } from 'node:path';
-import nextConfig from '../../next.config';
+import { fileURLToPath } from 'node:url';
+import { afterEach, describe, expect, it, vi } from 'vitest';
 import * as spaShellRoute from '../../app/[[...slug]]/page';
 
+const WEB_ROOT = dirname(fileURLToPath(new URL('../../..', import.meta.url)));
+
+async function loadNextConfig() {
+  vi.resetModules();
+  return (await import('../../next.config')).default;
+}
+
+afterEach(() => {
+  delete process.env.OD_WEB_DIST_DIR;
+  vi.resetModules();
+});
+
 describe('SPA shell export route', () => {
-  it('stays compatible with static export builds', () => {
+  it('stays compatible with static export builds', async () => {
+    const nextConfig = await loadNextConfig();
     expect(nextConfig.output).toBe('export');
+    expect(nextConfig.distDir).toBeUndefined();
     expect('dynamicParams' in spaShellRoute).toBe(false);
     expect(spaShellRoute.generateStaticParams()).toEqual([{ slug: [] }]);
   });
+
+  it('keeps an explicit dist dir override even when static export is selected', async () => {
+    const configuredDistDir = resolve(WEB_ROOT, '.tmp', 'vitest-next');
+    process.env.OD_WEB_DIST_DIR = configuredDistDir;
+
+    const nextConfig = await loadNextConfig();
+
+    expect(nextConfig.output).toBe('export');
+    expect(nextConfig.distDir).toContain('vitest-next');
+  });
+
+  it('treats an empty dist dir override as unset for static export builds', async () => {
+    process.env.OD_WEB_DIST_DIR = '';
+
+    const nextConfig = await loadNextConfig();
+
+    expect(nextConfig.output).toBe('export');
+    expect(nextConfig.distDir).toBeUndefined();
+  });
 });

vercel.json

@@ -1,6 +1,6 @@
 {
   "$schema": "https://openapi.vercel.sh/vercel.json",
-  "buildCommand": "pnpm install && pnpm --filter @open-design/web build",
+  "buildCommand": "OD_WEB_OUTPUT_MODE= pnpm --filter @open-design/web build",
   "installCommand": "pnpm install",
   "outputDirectory": "apps/web/out",
   "framework": null