fix(next-plugin): resolve WASM in Bun isolated installs

.changepacks/changepack_log_fixBunIsolatedWasmResolution20260830.json

@@ -0,0 +1,7 @@
+{
+  "changes": {
+    "packages/next-plugin/package.json": "Patch"
+  },
+  "note": "Resolve WASM from the plugin's physical install location in Bun isolated installs",
+  "date": "2026-08-30T03:43:34.977Z"
+}

packages/next-plugin/src/__tests__/wasm.test.ts

@@ -1,20 +1,43 @@
+import {
+  mkdirSync,
+  mkdtempSync,
+  rmSync,
+  symlinkSync,
+  writeFileSync,
+} from 'node:fs'
+import { tmpdir } from 'node:os'
+import { join } from 'node:path'
+
 import * as wasm from '@devup-ui/wasm'
 import * as webpackPlugin from '@devup-ui/webpack-plugin'
-import { afterEach, describe, expect, it } from 'bun:test'
+import { afterAll, afterEach, beforeAll, describe, expect, it } from 'bun:test'
 
 import {
   loadWasm,
   loadWebpackPlugin,
+  requireFromPlugin,
   requireWasm,
   setWasmForTesting,
   setWebpackPluginForTesting,
 } from '../wasm'
 
+const originalCwd = process.cwd()
+let tempRoots: string[] = []
+
+beforeAll(() => {
+  tempRoots = []
+})
+
 afterEach(() => {
+  process.chdir(originalCwd)
   setWasmForTesting(undefined)
   setWebpackPluginForTesting(undefined)
 })
 
+afterAll(() => {
+  for (const root of tempRoots) rmSync(root, { recursive: true, force: true })
+})
+
 describe('WASM selection', () => {
   it('uses an injected namespace in tests', () => {
     setWasmForTesting(wasm)
@@ -27,6 +50,44 @@ describe('WASM selection', () => {
     expect(typeof loadWasm(true).codeExtract).toBe('function')
   })
 
+  it('resolves dependencies from a Bun-style isolated install', () => {
+    const root = mkdtempSync(join(tmpdir(), 'devup-ui-next-isolated-'))
+    tempRoots.push(root)
+    const isolatedNodeModules = join(
+      root,
+      'node_modules/.bun/next-plugin/node_modules',
+    )
+    const pluginDir = join(isolatedNodeModules, '@devup-ui/next-plugin')
+    const wasmDir = join(isolatedNodeModules, '@devup-ui/wasm')
+    const rootScope = join(root, 'node_modules/@devup-ui')
+    mkdirSync(pluginDir, { recursive: true })
+    mkdirSync(wasmDir, { recursive: true })
+    mkdirSync(rootScope, { recursive: true })
+    writeFileSync(
+      join(pluginDir, 'package.json'),
+      JSON.stringify({ name: '@devup-ui/next-plugin' }),
+    )
+    writeFileSync(
+      join(wasmDir, 'package.json'),
+      JSON.stringify({ name: '@devup-ui/wasm', main: 'index.cjs' }),
+    )
+    writeFileSync(
+      join(wasmDir, 'index.cjs'),
+      'module.exports = { isolated: true }',
+    )
+    symlinkSync(
+      pluginDir,
+      join(rootScope, 'next-plugin'),
+      process.platform === 'win32' ? 'junction' : 'dir',
+    )
+
+    process.chdir(root)
+
+    expect(requireFromPlugin<{ isolated: boolean }>('@devup-ui/wasm')).toEqual({
+      isolated: true,
+    })
+  })
+
   it.each(['MODULE_NOT_FOUND', 'ERR_PACKAGE_PATH_NOT_EXPORTED'])(
     'falls back to the full package when the lite export fails with %s',
     (code) => {

packages/next-plugin/src/wasm.ts

@@ -1,4 +1,4 @@
-import { existsSync } from 'node:fs'
+import { existsSync, realpathSync } from 'node:fs'
 import { createRequire } from 'node:module'
 import { join } from 'node:path'
 
@@ -11,7 +11,8 @@ let fullWasm: DevupWasm | undefined
 let liteWasm: DevupWasm | undefined
 let webpackPlugin: DevupWebpackPlugin | undefined
 
-function requireFromPlugin<T>(specifier: string): T {
+/** @internal Resolve dependencies from the plugin's physical install location. */
+export function requireFromPlugin<T>(specifier: string): T {
   const installedPackage = join(
     process.cwd(),
     'node_modules/@devup-ui/next-plugin/package.json',
@@ -25,7 +26,7 @@ function requireFromPlugin<T>(specifier: string): T {
     : existsSync(workspacePackage)
       ? workspacePackage
       : join(process.cwd(), 'package.json')
-  return createRequire(requireBase)(specifier) as T
+  return createRequire(realpathSync(requireBase))(specifier) as T
 }
 
 type WasmLoader = (specifier: string) => DevupWasm