Bun preload plugin fails on Windows due to forward-slash-only regex and missing solid-js/web rule

[counter2015]

Description

The Bun preload plugin in @opentui/solid/scripts/solid-plugin.ts fails silently on Windows, causing solid-js to load its
server-side rendering (SSR) modules instead of the client-side ones. This results in runtime errors when rendering.

I try to run this locally, and find some problem, Claude Code help me to fix it by change local code, but I'm not familiar with ts and this project, need some help from mantainers to check whether this fix is right or not.

Here is the changed code and analysis from Claude Code.

Root Cause

Two issues in solid-plugin.ts:

1. Regex filters only match forward slashes

The onLoad filters use forward slashes to match paths:

build.onLoad({ filter: /\/node_modules\/solid-js\/dist\/server\.js$/ }, ...)
build.onLoad({ filter: /\/node_modules\/solid-js\/store\/dist\/server\.js$/ }, ...)

On Windows, Bun resolves module paths with backslashes (e.g. D:\project\node_modules\solid-js\dist\server.js), so these regex patterns
never match and the redirect silently fails.

2. Missing rule for solid-js/web/dist/server.js

The plugin redirects solid-js/dist/server.js → solid.js and solid-js/store/dist/server.js → store.js, but there is no rule for
solid-js/web/dist/server.js → web.js.

Since solid-js/web/package.json maps the "node" export condition to dist/server.js, Bun (which matches "node" by default) loads the
SSR version of solid-js/web, leading to errors like:

at render (node_modules/@opentui/solid/index.js:357:17)

Suggested Fix

Use [/\] in regex filters to match both path separators, and add the missing solid-js/web rule:

  build.onLoad({ filter: /[\/\\]node_modules[\/\\]solid-js[\/\\]dist[\/\\]server\.js$/ }, async (args) => {
    const path = args.path.replace("server.js", "solid.js")
    return { contents: await Bun.file(path).text(), loader: "js" }
  })
  build.onLoad({ filter: /[\/\\]node_modules[\/\\]solid-js[\/\\]store[\/\\]dist[\/\\]server\.js$/ }, async (args) => {
    const path = args.path.replace("server.js", "store.js")
    return { contents: await Bun.file(path).text(), loader: "js" }
  })
  build.onLoad({ filter: /[\/\\]node_modules[\/\\]solid-js[\/\\]web[\/\\]dist[\/\\]server\.js$/ }, async (args) => {
    const path = args.path.replace("server.js", "web.js")
    return { contents: await Bun.file(path).text(), loader: "js" }
  })

Environment

• OS: Windows 11
• Bun: 1.2.x
• @opentui/solid: 0.1.76 (also verified unfixed in 0.1.86)

[kommander]

Have you tried a newer bun version? Opencode uses that and has no issues on windows with that. Check the opencode build script.

[counter2015]

I reproduced this on Windows 11 with Bun 1.3.10 and @opentui/solid 0.1.87 (latest). Upgrading Bun does not resolve the issue.

[counter2015]

Environment: Windows, Bun 1.3.x, @opentui/solid 0.1.76 / 0.1.87

---

Root Cause

There are two bugs chained together:

Bug 1 — Windows path regex mismatch in Bun plugin

solid-plugin.ts intercepts solid-js/dist/server.js to redirect it to the client build:

build.onLoad({ filter: /\/node_modules\/solid-js\/dist\/server\.js$/ }, async (args) => {
  const path = args.path.replace("server.js", "solid.js")
  // ...
})

On Windows, Bun passes args.path using backslashes:

D:\project\node_modules\solid-js\dist\server.js

The regex only matches forward slashes, so the intercept silently fails. Bun then resolves solid-js under the "node" export condition → loads solid-js/dist/server.js (SSR version) instead of the client build.

Bug 2 — SSR Show returns "" instead of null

In solid-js/dist/server.js:

function Show(props) {
  let c;
  return props.when
    ? typeof (c = props.children) === "function" ? c(...) : c
    : props.fallback || "";  // ← returns "" when no fallback prop
}

When when is falsy and no fallback prop is provided, Show returns an empty string "". This string is then inserted into a box element, triggering _insertNode to throw:

Orphan text error: "" must have a <text> as a parent: box-N above text-node-N

---

Minimal Reproduction

Setup

mkdir opentui-repro
cd opentui-repro
bun init
bun add @opentui/solid solid-js

Add to bunfig.toml:

preload = ["@opentui/solid/preload"]

index.tsx

import { render } from "@opentui/solid"
import { Show } from "solid-js"
import { createSignal } from "solid-js"

function App() {
  const [visible, setVisible] = createSignal(false)
  return (
    <box>
      {/* Show without fallback, initial value false — triggers SSR bug */}
      <Show when={visible()}>
        <text>hello</text>
      </Show>
      <text>running</text>
    </box>
  )
}

render(() => <App />, { targetFps: 30 })

Run

# Reproduce the bug:
bun index.tsx

# Verify the workaround:
bun --conditions browser index.tsx

Why a simple app without <Show> won't reproduce

The bug only triggers when SSR Show returns "". If your test app has no <Show>, or all <Show> have a fallback prop, you will never hit this error.

---

Workaround

Add --conditions browser to the dev script in package.json:

{
  "scripts": {
    "dev": "bun --conditions browser src/index.ts"
  }
}

This forces Bun to use the browser export condition, which maps solid-js to ./dist/solid.js (the reactive client build), bypassing the broken plugin intercept entirely.

[kommander]

@Hona @Adictya why does opencode on windows not exhibit this issue?

[Adictya]

@Hona @Adictya why does opencode on windows not exhibit this issue?

opencode windows also gets built in a linux env so the plugin resolves the correct file

[kommander]

Makes sense, thanks. So this needs fixing.

[Adictya]

#637 this addresses it

[counter2015]

IMO, the path problem has fixed in this #820 ?

[counter2015]

The path-separator fix ([\\/]) was merged, but the second issue from this report is still unresolved.

solid-js/web/package.json maps the node export condition to dist/server.js.
Since Bun defaults to node, it loads the SSR version — and there's no onLoad
rule to redirect solid-js/web/dist/server.js → web.js.

Suggested addition to solid-plugin.ts:

build.onLoad({ filter: /[\/\\]node_modules[\/\\]solid-js[\/\\]web[\/\\]dist[\/\\]server\.js$/ }, async (args) => {
  const path = args.path.replace("server.js", "web.js")
  const file = Bun.file(path)
  const code = await file.text()
  return { contents: code, loader: "js" }
})

[Adictya]

What is the usecase for importing something from solid-js/web? Portal/Dynamic is re-exported from solid/src/elements/extras.ts, and other stuff mostly has to do with hydration etc.

the fix in #820 should fix your error imo

[counter2015]

Good point — solid-js/web isn't imported anywhere in @opentui/solid's source,
so the missing redirect rule is a non-issue for this package specifically.

Thanks for the clarification, and apologies for the noise — looks like #820 does
fully address the Windows problem.