Split REFLEX_CORS_ALLOWED_ORIGINS by comma

Default delimiter is colon with no stripping of whitespace. However for CORS
it's much more convenient to split on a comma.

Extend the env_var interpretation system to pull a new SequenceOptions object
out of an Annotated type hint.

Fix #6066

Author: masenf

reflex/config.py

@@ -10,14 +10,15 @@
 from importlib.util import find_spec
 from pathlib import Path
 from types import ModuleType
-from typing import TYPE_CHECKING, Any, ClassVar, Literal
+from typing import TYPE_CHECKING, Annotated, Any, ClassVar, Literal
 
 from reflex import constants
 from reflex.constants.base import LogLevel
 from reflex.environment import EnvironmentVariables as EnvironmentVariables
 from reflex.environment import EnvVar as EnvVar
 from reflex.environment import (
     ExistingPath,
+    SequenceOptions,
     _load_dotenv_from_files,
     _paths_from_env_files,
     interpret_env_var_value,
@@ -207,8 +208,10 @@ class BaseConfig:
     # Timeout to do a production build of a frontend page.
     static_page_generation_timeout: int = 60
 
-    # List of origins that are allowed to connect to the backend API.
-    cors_allowed_origins: Sequence[str] = dataclasses.field(default=("*",))
+    # Comma separated list of origins that are allowed to connect to the backend API.
+    cors_allowed_origins: Annotated[Sequence[str], SequenceOptions(delimiter=",")] = (
+        dataclasses.field(default=("*",))
+    )
 
     # Whether to use React strict mode.
     react_strict_mode: bool = True

reflex/environment.py

@@ -212,6 +212,17 @@ def interpret_enum_env(value: str, field_type: GenericType, field_name: str) ->
         raise EnvironmentVarValueError(msg) from ve
 
 
+@dataclasses.dataclass(frozen=True, kw_only=True, slots=True)
+class SequenceOptions:
+    """Options for interpreting Sequence environment variables."""
+
+    delimiter: str = ":"
+    strip: bool = False
+
+
+DEFAULT_SEQUENCE_OPTIONS = SequenceOptions()
+
+
 def interpret_env_var_value(
     value: str, field_type: GenericType, field_name: str
 ) -> Any:
@@ -278,14 +289,26 @@ def interpret_env_var_value(
                     continue
         msg = f"Invalid literal value: {value!r} for {field_name}, expected one of {literal_values}"
         raise EnvironmentVarValueError(msg)
+    # If the field is Annotated with SequenceOptions, extract the options
+    sequence_options = DEFAULT_SEQUENCE_OPTIONS
+    if get_origin(field_type) is Annotated:
+        annotated_args = get_args(field_type)
+        field_type = annotated_args[0]
+        for arg in annotated_args[1:]:
+            if isinstance(arg, SequenceOptions):
+                sequence_options = arg
+                break
     if get_origin(field_type) in (list, Sequence):
+        items = value.split(sequence_options.delimiter)
+        if sequence_options.strip:
+            items = [item.strip() for item in items]
         return [
             interpret_env_var_value(
                 v,
                 get_args(field_type)[0],
                 f"{field_name}[{i}]",
             )
-            for i, v in enumerate(value.split(":"))
+            for i, v in enumerate(items)
         ]
     if isinstance(field_type, type) and issubclass(field_type, enum.Enum):
         return interpret_enum_env(value, field_type, field_name)

tests/units/test_config.py

@@ -96,6 +96,41 @@ def test_update_from_env_path(
     assert config.bun_path == tmp_path
 
 
+def test_update_from_env_cors(
+    base_config_values: dict[str, Any],
+    monkeypatch: pytest.MonkeyPatch,
+    tmp_path: Path,
+):
+    """Test that environment variables override config values.
+
+    Args:
+        base_config_values: Config values.
+        monkeypatch: The pytest monkeypatch object.
+        tmp_path: The pytest tmp_path fixture object.
+    """
+    config = rx.Config(**base_config_values)
+    assert config.cors_allowed_origins == ("*",)
+
+    monkeypatch.setenv("REFLEX_CORS_ALLOWED_ORIGINS", "")
+    config = rx.Config(**base_config_values)
+    assert config.cors_allowed_origins == ("*",)
+
+    monkeypatch.setenv("REFLEX_CORS_ALLOWED_ORIGINS", "https://foo.example.com")
+    config = rx.Config(**base_config_values)
+    assert config.cors_allowed_origins == [
+        "https://foo.example.com",
+    ]
+
+    monkeypatch.setenv(
+        "REFLEX_CORS_ALLOWED_ORIGINS", "http://example.com, http://another.com "
+    )
+    config = rx.Config(**base_config_values)
+    assert config.cors_allowed_origins == [
+        "http://example.com",
+        "http://another.com",
+    ]
+
+
 @pytest.mark.parametrize(
     ("kwargs", "expected"),
     [

tests/units/test_environment.py

@@ -4,6 +4,7 @@
 import os
 import tempfile
 from pathlib import Path
+from typing import Annotated
 from unittest.mock import patch
 
 import pytest
@@ -15,6 +16,7 @@
     ExecutorType,
     ExistingPath,
     PerformanceMode,
+    SequenceOptions,
     _load_dotenv_from_files,
     _paths_from_env_files,
     _paths_from_environment,
@@ -175,6 +177,14 @@ def test_interpret_list(self):
         result = interpret_env_var_value("1:2:3", list[int], "TEST_FIELD")
         assert result == [1, 2, 3]
 
+    def test_interpret_annotated_sequence(self):
+        """Test annotated sequence interpretation."""
+        annotated_type = Annotated[
+            list[str], SequenceOptions(delimiter=",", strip=True)
+        ]
+        result = interpret_env_var_value("a, b, c ", annotated_type, "TEST_FIELD")
+        assert result == ["a", "b", "c"]
+
     def test_interpret_enum(self):
         """Test enum interpretation."""
         result = interpret_env_var_value("value1", _TestEnum, "TEST_FIELD")