Serving static files via hono on bun kills the prerenderer

[heddendorp]

Command

build

Is this a regression?

• Yes, this behavior used to work in the previous version

The previous version in which this bug was not present was

No response

Description

I wanted to use the new hybrid rendering with hono and bun.
Everything seems to work mostly fine until I try to serve static files from my server. This kills my build process as the route extraction fails.
As long as the static serving is commented out, the build is fine and works with bun and the dev server.

Minimal Reproduction

I have a repro here https://github.com/heddendorp/ssr-bun-test
Cloning, running bun install and bun run build will give you the error.
You can get rid of this line
https://github.com/heddendorp/ssr-bun-test/blob/d55241783177d8a940fe713dc4371e80a0eccec6/src/server.ts#L28
to make the build work.

Exception or Error

Prerendered 0 static routes.
Application bundle generation failed. [3.477 seconds]

✘ [ERROR] An error occurred while extracting routes.

Error: No handler function exported from C:\Users\hedde\code\evorto\node_modules\@angular\build\src\utils\server-rendering\routes-extractor-worker.js
    at [...]node_modules\piscina\dist\worker.js:142:23

Your Environment

Angular CLI: 19.0.0
Node: 22.4.0
Package Manager: bun 1.1.36
OS: win32 x64

Angular: 19.0.0
... animations, cli, common, compiler, compiler-cli, core, forms
... platform-browser, platform-browser-dynamic, platform-server
... router, ssr

Package                         Version
---------------------------------------------------------
@angular-devkit/architect       0.1900.0
@angular-devkit/build-angular   19.0.0
@angular-devkit/core            19.0.0
@angular-devkit/schematics      19.0.0
@schematics/angular             19.0.0
rxjs                            7.8.1
typescript                      5.6.3
zone.js                         0.15.0

Anything else relevant?

I'm happy to provide more context to clear this up

[alan-agius4]

Are you using bun as your runtime, or are you using Node.js? If it's the latter, import { serveStatic } from 'hono/bun' will not be valid.

Unfortunately, piscina is intercepting all errors during the initialization phase. https://github.com/piscinajs/piscina/blob/b64747233446ca4271e6aed744a740f637e278a5/src/worker.ts#L57

[heddendorp]

I am importing import { serveStatic } from 'hono/bun' and would think that I am using bun as a runtime (running bun run build).
How do I make sure that bun is running the build, I was thinking that it is more nody.
Edit: sorry for taking down the repo again, I underestimated what else came in other branches there 😅
I can create a new one tomorrow.

[alan-agius4]

It seems that you're using Bun as a package manager rather than as a runtime, which are two distinct tools.

To learn more about installing Bun as a runtime, check out the official documentation here: Bun Installation Guide.

[heddendorp]

Hey @alan-agius4 I did install bun and could also execute the built server with it.
The issue seems to only arise when running bun run build. I'm not sure how to influence the prerendering runtime that is used by angular during the build.
Sorry for my ignorance, I'll try to get a repo up that reproduces the issue, maybe that is more helpful.

[alan-agius4]

Can you update please update node_modules/@angular/build/src/utils/server-rendering/routes-extractor-worker.js to below and report back with the error you are seeing?

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
const worker_threads_1 = require("worker_threads");
const schema_1 = require("../../builders/application/schema");
const fetch_patch_1 = require("./fetch-patch");
const launch_server_1 = require("./launch-server");
const load_esm_from_memory_1 = require("./load-esm-from-memory");
/**
 * This is passed as workerData when setting up the worker via the `piscina` package.
 */
const { outputMode, hasSsrEntry } = worker_threads_1.workerData;
let serverURL = launch_server_1.DEFAULT_URL;
/** Renders an application based on a provided options. */
async function extractRoutes() {
    if (outputMode !== undefined && hasSsrEntry) {
      serverURL = await (0, launch_server_1.launchServer)();
    }
    (0, fetch_patch_1.patchFetchToLoadInMemoryAssets)(serverURL);

    const { ɵextractRoutesAndCreateRouteTree: extractRoutesAndCreateRouteTree } = await (0, load_esm_from_memory_1.loadEsmModuleFromMemory)('./main.server.mjs');
    const { routeTree, appShellRoute, errors } = await extractRoutesAndCreateRouteTree(serverURL, undefined /** manifest */, true /** invokeGetPrerenderParams */, outputMode === schema_1.OutputMode.Server /** includePrerenderFallbackRoutes */);
    return {
        errors,
        appShellRoute,
        serializedRouteTree: routeTree.toObject(),
    };
}
exports.default = extractRoutes;

[heddendorp]

I'm now getting a new error

Prerendered 0 static routes.
Application bundle generation failed. [4.350 seconds]

✘ [ERROR] An error occurred while extracting routes.

ReferenceError: Bun is not defined
    at file:///C:/Users/hedde/code/ssr-bun-test/.angular/prerender-root/09095c25-afdb-4a42-9070-e68c47fd62a3/server.mjs:1:23248
    at ModuleJob.run (node:internal/modules/esm/module_job:262:25)
    at async onImport.tracePromise.__proto__ (node:internal/modules/esm/loader:485:26)
    at async launchServer (C:\Users\hedde\code\ssr-bun-test\node_modules\@angular\build\src\utils\server-rendering\launch-server.js:27:28)
    at async extractRoutes (C:\Users\hedde\code\ssr-bun-test\node_modules\@angular\build\src\utils\server-rendering\routes-extractor-worker.js:16:17)
    at async C:\Users\hedde\code\ssr-bun-test\node_modules\piscina\dist\worker.js:144:26


error: script "build" exited with code 1

I also added both the patched and regular reproduction to https://github.com/heddendorp/ssr-bun-test

EDIT:
Some research showed https://bun.sh/docs/cli/run#bun (force the runtime to be bun). Curiously bun run --bun build just runs forever (more than two minutes). This happens with and without the patch applied.

[alan-agius4]

Thank you for the information. At this stage, it appears the issue lies with Bun, which is intended to serve as a drop-in replacement for Node.js. However, there seems to be a problem, possibly related to Workers or Atomics, that is causing unexpected behavior.