packages/uniwind/src/bundler/adapters/metro/transformer.ts (1)

12-34: 🩺 Stability & Availability | 🔵 Trivial | 💤 Low value

Cache not keyed by isExpoProject.

getTransformWorker caches the first resolved worker in the module-level worker variable regardless of the isExpoProject value on subsequent calls. This is fine as long as one Metro process only ever transforms files for a single project/config, but if this transformer module is ever reused across configs with differing isExpoProject within the same process, the stale cached worker would be returned — the same class of bug this PR is fixing.

♻️ Defensive fix: key the cache by isExpoProject

-let worker: typeof MetroTransformWorker | undefined
+const workerCache = new Map<boolean, typeof MetroTransformWorker>()

 const getTransformWorker = (isExpoProject?: boolean): typeof MetroTransformWorker => {
-    if (worker) {
-        return worker
+    const cacheKey = Boolean(isExpoProject)
+    const cached = workerCache.get(cacheKey)
+    if (cached) {
+        return cached
     }

     const resolvedWorker: typeof MetroTransformWorker = isExpoProject
         ? (() => {
             try {
                 const { unstable_transformerPath } = require('`@expo/metro-config`') as typeof ExpoMetroConfig

                 return require(unstable_transformerPath)
             } catch {
                 return require('`@expo/metro-config/build/transform-worker/transform-worker.js`')
             }
         })()
         : require('metro-transform-worker')

-    worker = resolvedWorker
+    workerCache.set(cacheKey, resolvedWorker)

     return resolvedWorker
 }

Please confirm whether a single Node process can host Metro transforms for multiple projects/configs in this monorepo's build tooling (e.g. programmatic multi-target builds); if not, this is purely defensive.

Also applies to: 45-45

🤖 Prompt for AI Agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

In `@packages/uniwind/src/bundler/adapters/metro/transformer.ts` around lines 12 -
34, The module-level cache in getTransformWorker is not keyed by isExpoProject,
so a worker resolved for one project type can be incorrectly reused for another.
Update getTransformWorker in transformer.ts to cache separate resolved workers
for Expo and non-Expo calls (or otherwise key the cache by isExpoProject) while
keeping the existing lazy resolution logic around MetroTransformWorker and
ExpoMetroConfig.