fix: make sure that the initOpenNextCloudflareForDev() logic runs only once (#293)

Author: dario-piotrowicz

.changeset/friendly-ears-ring.md

@@ -0,0 +1,10 @@
+---
+"@opennextjs/cloudflare": patch
+---
+
+fix: make sure that the `initOpenNextCloudflareForDev()` logic runs only once
+
+Currently calling `initOpenNextCloudflareForDev()` in the Next.js config file causes
+this initialization logic to run twice, consuming more resources and causing extra
+noise in the terminal logs, this change makes sure that the initialization logic
+is run only once instead

packages/cloudflare/src/api/cloudflare-context.ts

@@ -89,13 +89,32 @@ export function getCloudflareContext<
  * Note: this function should only be called inside the Next.js config file, and although async it doesn't need to be `await`ed
  */
 export async function initOpenNextCloudflareForDev() {
+  const shouldInitializationRun = shouldContextInitializationRun();
+  if (!shouldInitializationRun) return;
+
   const context = await getCloudflareContextFromWrangler();
 
   addCloudflareContextToNodejsGlobal(context);
 
   await monkeyPatchVmModuleEdgeContext(context);
 }
 
+/**
+ * Next dev server imports the config file twice (in two different processes, making it hard to track),
+ * this causes the initialization to run twice as well, to keep things clean, not allocate extra
+ * resources (i.e. instantiate two miniflare instances) and avoid extra potential logs, it would be best
+ * to run the initialization only once, this function is used to try to make it so that it does, it returns
+ * a flag which indicates if the initialization should run in the current process or not.
+ *
+ * @returns boolean indicating if the initialization should run
+ */
+function shouldContextInitializationRun(): boolean {
+  // via debugging we've seen that AsyncLocalStorage is only set in one of the
+  // two processes so we're using it as the differentiator between the two
+  const AsyncLocalStorage = (globalThis as unknown as { AsyncLocalStorage?: unknown })["AsyncLocalStorage"];
+  return !!AsyncLocalStorage;
+}
+
 /**
  * Adds the cloudflare context to the global scope in which the Next.js dev node.js process runs in, enabling
  * future calls to `getCloudflareContext` to retrieve and return such context