fix: update flag impl

Author: Skn0tt

.github/workflows/e2e-appdir.yml

@@ -6,6 +6,9 @@ on:
   push:
     branches: [main]
 
+env:
+  NEXT_SPLIT_API_ROUTES: true
+
 jobs:
   setup:
     runs-on: ubuntu-latest

.github/workflows/e2e-next.yml

@@ -8,6 +8,9 @@ on:
   schedule:
     - cron: '0 0 * * *'
 
+env:
+  NEXT_SPLIT_API_ROUTES: true
+
 jobs:
   setup:
     runs-on: ubuntu-latest

.github/workflows/test-integration.yml

@@ -9,6 +9,9 @@ concurrency:
   group: ${{ github.workflow }}-${{ github.head_ref || github.run_id }}
   cancel-in-progress: true
 
+env:
+  NEXT_SPLIT_API_ROUTES: true
+
 jobs:
   build:
     name: Integration tests

.github/workflows/test.yml

@@ -11,6 +11,9 @@ concurrency:
   group: ${{ github.workflow }}-${{ github.head_ref || github.run_id }}
   cancel-in-progress: true
 
+env:
+  NEXT_SPLIT_API_ROUTES: true
+
 jobs:
   build:
     name: Unit tests

packages/runtime/src/helpers/flags.ts

@@ -1,3 +1,5 @@
+import destr from 'destr'
+
 /**
  * If this flag is enabled, we generate individual Lambda functions for API Routes.
  * They're packed together in 50mb chunks to avoid hitting the Lambda size limit.
@@ -9,13 +11,7 @@
  * If disabled, we bundle all API Routes into a single function.
  * This is can lead to large bundle sizes.
  *
- * Enabled by default. Can be disabled by passing NEXT_SPLIT_API_ROUTES=false.
+ * Disabled by default. Can be overriden using the NEXT_SPLIT_API_ROUTES env var.
  */
-
-export const splitApiRoutes = (featureFlags: Record<string, unknown>): boolean => {
-  if (process.env.NEXT_SPLIT_API_ROUTES) {
-    return process.env.NEXT_SPLIT_API_ROUTES === 'true'
-  }
-  // default to true during testing, swap to false before merging
-  return typeof featureFlags.next_split_api_routes === 'boolean' ? featureFlags.next_split_api_routes : true
-}
+export const splitApiRoutes = (featureFlags: Record<string, unknown>): boolean =>
+  destr(process.env.NEXT_SPLIT_API_ROUTES) ?? featureFlags.next_split_api_routes ?? false