OpenNext Middleware WASM issue

Getting started

Prerequisites

• Node.js 22
• NPM - to manage dependencies (usually comes installed with Node)
• Cloudflare account to create a D1 database

Reproduction steps

1. Install dependencies with npm i
2. Start the Next.js Wrangler preview server with npm run preview
3. You should see the following error: Error: Build failed with 1 error: .open-next/server-functions/default/middleware.mjs:6752:59: ERROR: Could not resolve "./wasm/wasm_ea010aa52414c7de383495546f15cb7d49b055fc.wasm"

Setting up D1 database for further testing

1. npx wrangler d1 create <insert-db-name>.
   • I have not found a way to create a D1 database only for local use with Wrangler. I assume you have a Cloudflare account that can create a remote D1 database?
2. Add config for the D1 database in wrangler.jsonc:

	"d1_databases": [
		{
			"binding": "DB",
			"database_name": "<insert-database-name>",
			"database_id": "<insert-database-id>",
			"migrations_dir": "./migrations"
		}
	]

3. npm run generate-db-types.
   • This will generate the Prisma JavaScript client in node_modules based on src/schema.prisma.
4. npm run dev and visit localhost:3000.
   • This should generate the local D1 .sqlite files at /opennext-middleware-wasm-issue/.wrangler/state/v3/d1/miniflare-D1DatabaseObject. You can ignore the errors when visiting localhost:3000.
5. npx wrangler d1 migrations create <insert-database-name> create_tables
6. npx prisma migrate diff --from-local-d1 --to-schema-datamodel ./src/schema.prisma --script --output ./migrations/0001_create_tables.sql.
   • Generates migration script to create the initial tables with Prisma
7. npx wrangler d1 migrations apply <insert-database-name>
   • Tables should now be create in local D1 database

After that the database schema should be there without any populated data. Which should be enough to test the await db['account'].findMany(); query in middleware.ts with npm run preview.