refactor(ts-code-mode-web): simplify Bun Vite config

Drop the quickjs-bun path walker/plugin/alias. Keep the working pattern:
browser-only client resolve conditions, bun on SSR only, externalize
quickjs-bun + the isolate driver, and CODE_MODE_BUN/Nitro bun preset.

Author: tombeckenham

examples/ts-code-mode-web/vite.config.ts

@@ -1,23 +1,14 @@
-import { existsSync } from 'node:fs'
-import { dirname, join } from 'node:path'
-import { fileURLToPath } from 'node:url'
-import { defineConfig, type Plugin } from 'vite'
+import { defineConfig } from 'vite'
 import { tanstackStart } from '@tanstack/react-start/plugin/vite'
 import { nitro } from 'nitro/vite'
 import viteReact from '@vitejs/plugin-react'
 import tailwindcss from '@tailwindcss/vite'
 import { devtools } from '@tanstack/devtools-vite'
 
 // Native / wasm / binary server-only modules that can't be bundled by esbuild
-// or rolldown (isolated-vm is a `.node` addon, the quickjs engines ship wasm,
-// esbuild/puppeteer carry platform binaries). They stay external in every pass.
-// nitro 3's server build (rolldown) externalizes node_modules but must *resolve*
-// each external at build time; under pnpm these live under the isolate adapters'
-// nested store dirs, so they're declared as direct dependencies of this example
-// (see package.json) so the resolve succeeds. The pure-JS server deps that the
-// old nitro-v2 externals list also named (google-auth-library, gaxios, jws,
-// gcp-metadata, google-logging-utils, ws, node-fetch, openai) are left to be
-// bundled normally — nitro 3 handles them without an explicit external entry.
+// or rolldown. They stay external so the host runtime loads them.
+// Under pnpm, declare them as direct deps of this example so nitro can resolve
+// them (see package.json).
 const SERVER_ONLY_NATIVE = [
   'isolated-vm',
   'esbuild',
@@ -28,80 +19,30 @@ const SERVER_ONLY_NATIVE = [
   '@jitl/quickjs-wasmfile-release-sync',
   '@jitl/quickjs-wasmfile-debug-asyncify',
   '@jitl/quickjs-wasmfile-debug-sync',
+  // Bun-native QuickJS (exports.bun only) — host Bun loads it, not Vite.
   'quickjs-bun',
+  '@tanstack/ai-isolate-quickjs-bun',
+  'bun:ffi',
 ]
 
-/**
- * quickjs-bun only publishes `exports["."].bun` (no import/default). Vite/Node
- * package resolution always fails on that map — even with `conditions: ['bun']`
- * under Nitro's module runner (which still hits resolvePackageEntry). Point at
- * the package's `index.ts` on disk and mark it external so the Bun runtime
- * loads it natively (bun:ffi + TypeScript).
- */
-function resolveQuickjsBunIndex(): string {
-  const starts = [
-    dirname(fileURLToPath(import.meta.url)),
-    process.cwd(),
-  ]
-  for (const start of starts) {
-    let dir = start
-    for (let i = 0; i < 14; i++) {
-      const candidates = [
-        join(dir, 'node_modules', 'quickjs-bun', 'index.ts'),
-        join(
-          dir,
-          'packages',
-          'ai-isolate-quickjs-bun',
-          'node_modules',
-          'quickjs-bun',
-          'index.ts',
-        ),
-      ]
-      for (const candidate of candidates) {
-        if (existsSync(candidate)) return candidate
-      }
-      const parent = dirname(dir)
-      if (parent === dir) break
-      dir = parent
-    }
-  }
-  throw new Error(
-    'Could not locate quickjs-bun/index.ts. Run pnpm install from the monorepo root.',
-  )
-}
-
-const quickjsBunIndex = resolveQuickjsBunIndex()
-
-function quickjsBunResolvePlugin(): Plugin {
-  return {
-    name: 'resolve-quickjs-bun-entry',
-    enforce: 'pre',
-    resolveId(id) {
-      // Bare package or deep imports → absolute entry, always external so the
-      // Vite module runner never runInlinedModule()'s quickjs-bun (that path
-      // throws strict-mode SyntaxError on Bun-oriented source).
-      if (
-        id === 'quickjs-bun' ||
-        id.startsWith('quickjs-bun/') ||
-        id === quickjsBunIndex ||
-        id.endsWith('/quickjs-bun/index.ts') ||
-        id.includes('/quickjs-bun/src/')
-      ) {
-        return { id: quickjsBunIndex, external: true }
-      }
-      return null
-    },
-  }
-}
-
 /** `CODE_MODE_BUN=1` or running the Vite CLI under Bun enables Bun isolate defaults. */
 const codeModeBun =
   process.env.CODE_MODE_BUN === '1' ||
   typeof (process.versions as { bun?: string }).bun === 'string'
 
-const config = defineConfig({
+/**
+ * Same lessons as the Bun Code Mode path:
+ *
+ * - Do **not** put `bun` in top-level `resolve.conditions`. router-core's
+ *   `isServer` maps `bun` → server build; the browser would get isServer=true,
+ *   createRouter never builds a store, hydrateStart crashes on `router.state`.
+ * - Put `bun` only on `ssr.resolve.conditions` so `quickjs-bun` resolves under Bun.
+ * - Externalize quickjs-bun + the isolate driver so Vite never inlines them.
+ *
+ * `pnpm dev:bun` → CODE_MODE_BUN=1 bun --bun vite dev
+ */
+export default defineConfig({
   define: {
-    // Client UI defaults (selected isolate VM) follow the same flag.
     'import.meta.env.VITE_CODE_MODE_BUN': JSON.stringify(
       codeModeBun ? '1' : '',
     ),
@@ -111,19 +52,11 @@ const config = defineConfig({
   },
   resolve: {
     tsconfigPaths: true,
-    // Client must prefer `browser` over `bun`. router-core's isServer maps
-    // `bun` → server build (isServer=true); if the browser gets that, hydrate
-    // crashes on router.state. quickjs-bun is handled by the plugin + ssr.conditions.
+    // Client: browser/import only — never prefer `bun` here.
     conditions: ['import', 'module', 'browser', 'default'],
-    alias: {
-      // Belt-and-suspenders for static analysis / tools that don't use resolveId
-      'quickjs-bun': quickjsBunIndex,
-    },
   },
   plugins: [
-    quickjsBunResolvePlugin(),
     devtools(),
-    // Bun-optimized server only when in Bun mode — default Node Nitro for `pnpm dev`.
     // https://bun.com/docs/guides/ecosystem/tanstack-start
     nitro(codeModeBun ? { preset: 'bun' } : {}),
     tailwindcss(),
@@ -133,14 +66,16 @@ const config = defineConfig({
   ssr: {
     external: SERVER_ONLY_NATIVE,
     resolve: {
-      // Always allow `bun` on the server so quickjs-bun resolves when the
-      // process is actually Bun (even without CODE_MODE_BUN).
+      // Server under Bun: need `bun` for quickjs-bun's export map.
       conditions: ['bun', 'node', 'import', 'module', 'default'],
     },
   },
   optimizeDeps: {
-    exclude: ['isolated-vm', 'quickjs-emscripten', 'quickjs-bun'],
+    exclude: [
+      'isolated-vm',
+      'quickjs-emscripten',
+      'quickjs-bun',
+      '@tanstack/ai-isolate-quickjs-bun',
+    ],
   },
 })
-
-export default config