fix and test bug in config env loading

reflex/config.py

@@ -3,6 +3,7 @@
 from __future__ import annotations
 
 import importlib
+import inspect
 import os
 import sys
 import urllib.parse
@@ -10,6 +11,7 @@ from pathlib import Path
 from typing import Any, Dict, List, Optional, Set, Union
 
 from reflex.utils.exceptions import ConfigError
+from reflex.utils.types import is_optional, is_union
 
 try:
     import pydantic.v1 as pydantic
@@ -299,15 +301,23 @@ class Config(Base):
                     )
 
                 # Convert the env var to the expected type.
+                type_ = field.type_
+                if is_optional(type_):
+                    type_ = type_.__args__[0] or type_.__args__[1]
+                # TODO: This just handles the first type in a Union. Needs refactoring.
+                if is_union(type_):
+                    type_ = type_.__args__[0]
                 try:
-                    if issubclass(field.type_, bool):
+                    if type_ is bool or (
+                        inspect.isclass(type_) and issubclass(type_, bool)
+                    ):
                         # special handling for bool values
                         env_var = env_var.lower() in ["true", "1", "yes"]
                     else:
-                        env_var = field.type_(env_var)
+                        env_var = type_(env_var)
                 except ValueError as ve:
                     console.error(
-                        f"Could not convert {key.upper()}={env_var} to type {field.type_}"
+                        f"Could not convert {key.upper()}={env_var} to type {type_}"
                     )
                     raise EnvVarValueError from ve
 

tests/units/test_config.py

@@ -1,5 +1,6 @@
 import multiprocessing
 import os
+from typing import Any, Dict
 
 import pytest
 
@@ -28,6 +29,7 @@ def test_set_app_name(base_config_values):
     "env_var, value",
     [
         ("APP_NAME", "my_test_app"),
+        ("BUN_PATH", "/test"),
         ("FRONTEND_PORT", 3001),
         ("FRONTEND_PATH", "/test"),
         ("BACKEND_PORT", 8001),
@@ -41,7 +43,12 @@ def test_set_app_name(base_config_values):
         ("TELEMETRY_ENABLED", True),
     ],
 )
-def test_update_from_env(base_config_values, monkeypatch, env_var, value):
+def test_update_from_env(
+    base_config_values: Dict[str, Any],
+    monkeypatch: pytest.MonkeyPatch,
+    env_var: str,
+    value: Any,
+):
     """Test that environment variables override config values.
 
     Args: