bump nextJS to v15 (#4630)

* bump nextJS to v15

* make turbopack depends on env var

reflex/config.py

@@ -567,6 +567,9 @@ class EnvironmentVariables:
     # The maximum size of the reflex state in kilobytes.
     REFLEX_STATE_SIZE_LIMIT: EnvVar[int] = env_var(1000)
 
+    # Whether to use the turbopack bundler.
+    REFLEX_USE_TURBOPACK: EnvVar[bool] = env_var(True)
+
 
 environment = EnvironmentVariables()
 

reflex/constants/installer.py

@@ -182,7 +182,7 @@ class PackageJson(SimpleNamespace):
         "@emotion/react": "11.13.3",
         "axios": "1.7.7",
         "json5": "2.2.3",
-        "next": "14.2.16",
+        "next": "15.1.4",
         "next-sitemap": "4.2.3",
         "next-themes": "0.4.3",
         "react": "18.3.1",

reflex/utils/prerequisites.py

@@ -610,10 +610,14 @@ def initialize_web_directory():
     init_reflex_json(project_hash=project_hash)
 
 
+def _turbopack_flag() -> str:
+    return " --turbopack" if environment.REFLEX_USE_TURBOPACK.get() else ""
+
+
 def _compile_package_json():
     return templates.PACKAGE_JSON.render(
         scripts={
-            "dev": constants.PackageJson.Commands.DEV,
+            "dev": constants.PackageJson.Commands.DEV + _turbopack_flag(),
             "export": constants.PackageJson.Commands.EXPORT,
             "export_sitemap": constants.PackageJson.Commands.EXPORT_SITEMAP,
             "prod": constants.PackageJson.Commands.PROD,