fix(tailwindcss-patch): fallback to workspace source modules

Author: sonofmagic

packages/tailwindcss-patch/src/config/workspace.ts

@@ -19,20 +19,26 @@ function isNodeError(error: unknown): error is NodeJS.ErrnoException {
   return !!error && typeof error === 'object' && ('code' in error || 'message' in error)
 }
 
-function isMissingConfigModuleError(error: unknown) {
-  if (!isNodeError(error) || error.code !== 'MODULE_NOT_FOUND') {
+export function isMissingModuleError(error: unknown, pkgName: string) {
+  if (!isNodeError(error)) {
     return false
   }
-  const message = error.message ?? ''
-  return message.includes('@tailwindcss-mangle/config')
-}
 
-function isMissingSharedModuleError(error: unknown) {
-  if (!isNodeError(error) || error.code !== 'MODULE_NOT_FOUND') {
+  const code = error.code
+  if (code !== 'MODULE_NOT_FOUND' && code !== 'ERR_MODULE_NOT_FOUND') {
     return false
   }
+
   const message = error.message ?? ''
-  return message.includes('@tailwindcss-mangle/shared')
+  return message.includes(pkgName) || message.includes(`${pkgName}/dist/`)
+}
+
+function isMissingConfigModuleError(error: unknown) {
+  return isMissingModuleError(error, '@tailwindcss-mangle/config')
+}
+
+function isMissingSharedModuleError(error: unknown) {
+  return isMissingModuleError(error, '@tailwindcss-mangle/shared')
 }
 
 export async function loadWorkspaceConfigModule() {

packages/tailwindcss-patch/test/config.workspace.test.ts

@@ -0,0 +1,37 @@
+import { describe, expect, it } from 'vitest'
+import { isMissingModuleError } from '../src/config/workspace'
+
+function createNodeError(code: string, message: string) {
+  const error = new Error(message) as NodeJS.ErrnoException
+  error.code = code
+  return error
+}
+
+describe('workspace module resolution guards', () => {
+  it('treats ERR_MODULE_NOT_FOUND for workspace dist entries as fallback-worthy', () => {
+    const error = createNodeError(
+      'ERR_MODULE_NOT_FOUND',
+      `Cannot find module '/repo/node_modules/@tailwindcss-mangle/shared/dist/index.js' imported from /repo/packages/tailwindcss-patch/src/config/workspace.ts`,
+    )
+
+    expect(isMissingModuleError(error, '@tailwindcss-mangle/shared')).toBe(true)
+  })
+
+  it('treats classic MODULE_NOT_FOUND package lookup errors as fallback-worthy', () => {
+    const error = createNodeError(
+      'MODULE_NOT_FOUND',
+      `Cannot find module '@tailwindcss-mangle/config' imported from /repo/packages/tailwindcss-patch/src/config/workspace.ts`,
+    )
+
+    expect(isMissingModuleError(error, '@tailwindcss-mangle/config')).toBe(true)
+  })
+
+  it('ignores unrelated missing-module errors', () => {
+    const error = createNodeError(
+      'ERR_MODULE_NOT_FOUND',
+      `Cannot find module '/repo/node_modules/other-package/dist/index.js' imported from /repo/packages/tailwindcss-patch/src/config/workspace.ts`,
+    )
+
+    expect(isMissingModuleError(error, '@tailwindcss-mangle/shared')).toBe(false)
+  })
+})