Inconsistent assetsBuildDirectory path in "build/server/assets/server-build-[hash].js" while nested building in Windows

[adelriosantiago]

Reproduction

-Grab a project with a vite.config.js.
-Build in Windows with buildDirectory: 'build/test' then with buildDirectory: 'build\\test'.
-Both builds at "build/server/assets/server-build-[hash].js" will have the same "assetsBuildDirectory" apth which works only in Windows.
-I would expect the "assetsBuildDirectory" to have "/" like all other lines, instead the file includes:

//...
const mode = "pre-prod";
const assetsBuildDirectory = "artifacts\\test\\client";
const basename = "/";
//...

System Info

System:
    OS: Windows 10 10.0.19045
    CPU: (12) x64 AMD Ryzen 5 3600 6-Core Processor
    Memory: 7.72 GB / 15.95 GB
  Binaries:
    Node: 20.13.1 - C:\Program Files\nodejs\node.EXE
    Yarn: 1.22.22 - ~\AppData\Roaming\npm\yarn.CMD
    npm: 10.5.2 - C:\Program Files\nodejs\npm.CMD
    pnpm: 9.4.0 - ~\AppData\Roaming\npm\pnpm.CMD
  Browsers:
    Edge: Chromium (128.0.2739.79)
    Internet Explorer: 11.0.19041.4355

Used Package Manager

npm

Expected Behavior

I would expect the builder to keep be buildDirectory: 'build/test', which works both in Windows and Linux.

Actual Behavior

The line is buildDirectory: 'build\\test' when built in Windows, and buildDirectory: 'build/test' (correct) in Linux. The latter one works in Windows and Linux.

[pancakeslp]

Had a similar issue
I noticed that after you do a build (npx remix vite:build), if you ship the build artefacts from windows to linux or vice versa the build is unusable (recently found out my jenkins is on windows for some strange reason).

I've only observed this when trying to host if remix-serve (and any derivative using express), but I assume it originates in the build steps themselves.

in build/server/index.js the value of assetsBuildDirectory will vary depending on platform you are using to build
linux

const assetsBuildDirectory = "build/client";

windows

const assetsBuildDirectory = "build\\client";

Also if you specify assetsBuildDirectory in your remix config or your vite config that doesnt seem to resolve this.

---

Not sure anyone is interested in my work around, but if you are in a similarly weird build situation you can patch your local copy of remix-serve/cli.ts (link to original for reference https://github.com/remix-run/remix/blob/main/packages/remix-serve/cli.ts)

find the below (currently line 71 of remix-serve/cli.ts)

    return import(url.pathToFileURL(buildPath).href + "?t=" + stat.mtimeMs);

replace with

    const build = await import(
      url.pathToFileURL(buildPath).href + "?t=" + stat.mtimeMs
    );
    return correctBuildAssetsBuildDirectory(build);

and some extra code

import { ServerBuild } from "@remix-run/node";
import path from "node:path";

function correctBuildAssetsBuildDirectory(build: ServerBuild) {
  if (!build || !build.assetsBuildDirectory) {
    return build;
  }

  let assetsBuildDirectoryParts;
  if (build.assetsBuildDirectory.includes("/")) {
    assetsBuildDirectoryParts = build.assetsBuildDirectory.split("/");
  } else {
    assetsBuildDirectoryParts = build.assetsBuildDirectory.split("\\");
  }

  const assetsBuildDirectory = path.join(...assetsBuildDirectoryParts);
  return { ...build, assetsBuildDirectory };
}

[adelriosantiago]

This looks like a great PR @pancakeslp. Are you planning to submit it? Thanks.

[pancakeslp]

I wasn't originally planning on submitting it as a PR. As I was expecting someone would complain that this is a hack or partial fix, and it doesn't solve the root cause. (and React Router 7 is coming soon, so probably most people will migrate off Remix)

But after your suggestion @adelriosantiago, I thought why not.

A bug fix PR requires a new test be added, fair enough - reference https://remix.run/docs/en/main/guides/contributing#bug-fix-pull-requests
But after looking into code for remix-serve, I'm getting cold feet as there dont appear to be any existing tests for remix-serve (or I'm blind).

Option 1. Write a integration test instantiating remix-serve (and providing a bundle with slashes the wrong way around).
This feels weird considering remix-serve is meant to live for a long period of time (and not exit within a second of running); so I imagine we would also need to add code to find and kill the process too. And then add code for this test to run on multiple platforms (having previously found instances of if(process.platform === "win32"){...}.

Option 2. Write a unit test just testing the function correctBuildAssetsBuildDirectory from the code snippet in the previous post. Under scrutiny this would also not hold up to writing a failing test (requested by the contribution guide). To write a failing test I think I would first need to restructure the code in remix-serve https://github.com/remix-run/remix/blob/main/packages/remix-serve/cli.ts and that feels a little sketchy (as in sketchy to re-write it, to prove there is a bug).

Option 3. Run away and hope the snippet in the previous post was useful to someone

... I think I'll take option 3, and accept criticism I'm being cowardly/lazy