run the next build command using the correct package manager

packages/cloudflare/package.json

@@ -48,6 +48,7 @@
     "glob": "catalog:",
     "globals": "catalog:",
     "next": "catalog:",
+    "package-manager-detector": "catalog:",
     "tsup": "catalog:",
     "typescript": "catalog:",
     "typescript-eslint": "catalog:",

packages/cloudflare/src/cli/build/build-next-app.ts

@@ -1,3 +1,4 @@
+import { type AgentName as PackageManager, detect } from "package-manager-detector";
 import { execSync } from "node:child_process";
 
 /**
@@ -7,17 +8,19 @@ import { execSync } from "node:child_process";
  *
  * @param nextAppDir the directory of the app to build
  */
-export function buildNextjsApp(nextAppDir: string): void {
-  runNextBuildCommand("pnpm", nextAppDir);
+export async function buildNextjsApp(nextAppDir: string): Promise<void> {
+  const pm = await detect();
+
+  if (!pm) {
+    throw new Error("Fatal Error: package manager detection failed, aborting");
+  }
+
+  runNextBuildCommand(pm.name, nextAppDir);
 }
 
 // equivalent to: https://github.com/sst/open-next/blob/f61b0e94/packages/open-next/src/build.ts#L175-L186
-function runNextBuildCommand(
-  // let's keep things simple and just support only pnpm for now
-  packager: "pnpm" /*"npm" | "yarn" | "pnpm" | "bun"*/,
-  nextAppDir: string
-) {
-  const command = ["bun", "npm"].includes(packager) ? `${packager} next build` : `${packager} next build`;
+function runNextBuildCommand(packager: PackageManager, nextAppDir: string) {
+  const command = `${packager === "npm" ? "npx" : packager} next build`;
   execSync(command, {
     stdio: "inherit",
     cwd: nextAppDir,

packages/cloudflare/src/cli/build/index.ts

@@ -17,7 +17,7 @@ import { rm } from "node:fs/promises";
 export async function build(appDir: string, opts: BuildOptions): Promise<void> {
   if (!opts.skipBuild) {
     // Build the next app
-    buildNextjsApp(appDir);
+    await buildNextjsApp(appDir);
   }
 
   if (!containsDotNextDir(appDir)) {

pnpm-workspace.yaml

@@ -24,3 +24,4 @@ catalog:
   "globals": ^15.9.0
   "typescript-eslint": ^8.7.0
   "eslint-plugin-unicorn": ^55.0.0
+  "package-manager-detector": ^0.2.0