improve hot reload handling (#4795)

reflex/config.py

@@ -23,6 +23,7 @@ from typing import (
     Set,
     TypeVar,
     get_args,
+    get_origin,
 )
 
 from typing_extensions import Annotated, get_type_hints
@@ -304,6 +305,15 @@ def interpret_env_var_value(
         return interpret_path_env(value, field_name)
     elif field_type is ExistingPath:
         return interpret_existing_path_env(value, field_name)
+    elif get_origin(field_type) is list:
+        return [
+            interpret_env_var_value(
+                v,
+                get_args(field_type)[0],
+                f"{field_name}[{i}]",
+            )
+            for i, v in enumerate(value.split(":"))
+        ]
     elif inspect.isclass(field_type) and issubclass(field_type, enum.Enum):
         return interpret_enum_env(value, field_type, field_name)
 
@@ -387,7 +397,11 @@ class EnvVar(Generic[T]):
         else:
             if isinstance(value, enum.Enum):
                 value = value.value
-            os.environ[self.name] = str(value)
+            if isinstance(value, list):
+                str_value = ":".join(str(v) for v in value)
+            else:
+                str_value = str(value)
+            os.environ[self.name] = str_value
 
 
 class env_var:  # noqa: N801 # pyright: ignore [reportRedeclaration]
@@ -571,6 +585,12 @@ class EnvironmentVariables:
     # Whether to use the turbopack bundler.
     REFLEX_USE_TURBOPACK: EnvVar[bool] = env_var(True)
 
+    # Additional paths to include in the hot reload. Separated by a colon.
+    REFLEX_HOT_RELOAD_INCLUDE_PATHS: EnvVar[List[Path]] = env_var([])
+
+    # Paths to exclude from the hot reload. Takes precedence over include paths. Separated by a colon.
+    REFLEX_HOT_RELOAD_EXCLUDE_PATHS: EnvVar[List[Path]] = env_var([])
+
 
 environment = EnvironmentVariables()
 

reflex/utils/exec.py

@@ -10,6 +10,7 @@ import re
 import subprocess
 import sys
 from pathlib import Path
+from typing import Sequence
 from urllib.parse import urljoin
 
 import psutil
@@ -242,14 +243,14 @@ def run_backend(
         run_uvicorn_backend(host, port, loglevel)
 
 
-def get_reload_dirs() -> list[Path]:
-    """Get the reload directories for the backend.
+def get_reload_paths() -> Sequence[Path]:
+    """Get the reload paths for the backend.
 
     Returns:
-        The reload directories for the backend.
+        The reload paths for the backend.
     """
     config = get_config()
-    reload_dirs = [Path(config.app_name)]
+    reload_paths = [Path(config.app_name).parent]
     if config.app_module is not None and config.app_module.__file__:
         module_path = Path(config.app_module.__file__).resolve().parent
 
@@ -263,8 +264,43 @@ def get_reload_dirs() -> list[Path]:
             else:
                 break
 
-        reload_dirs = [module_path]
-    return reload_dirs
+        reload_paths = [module_path]
+
+    include_dirs = tuple(
+        map(Path.absolute, environment.REFLEX_HOT_RELOAD_INCLUDE_PATHS.get())
+    )
+    exclude_dirs = tuple(
+        map(Path.absolute, environment.REFLEX_HOT_RELOAD_EXCLUDE_PATHS.get())
+    )
+
+    def is_excluded_by_default(path: Path) -> bool:
+        if path.is_dir():
+            if path.name.startswith("."):
+                # exclude hidden directories
+                return True
+            if path.name.startswith("__"):
+                # ignore things like __pycache__
+                return True
+        return path.name not in (".gitignore", "uploaded_files")
+
+    reload_paths = (
+        tuple(
+            path.absolute()
+            for dir in reload_paths
+            for path in dir.iterdir()
+            if not is_excluded_by_default(path)
+        )
+        + include_dirs
+    )
+
+    if exclude_dirs:
+        reload_paths = tuple(
+            path
+            for path in reload_paths
+            if all(not path.samefile(exclude) for exclude in exclude_dirs)
+        )
+
+    return reload_paths
 
 
 def run_uvicorn_backend(host: str, port: int, loglevel: LogLevel):
@@ -283,7 +319,7 @@ def run_uvicorn_backend(host: str, port: int, loglevel: LogLevel):
         port=port,
         log_level=loglevel.value,
         reload=True,
-        reload_dirs=list(map(str, get_reload_dirs())),
+        reload_dirs=list(map(str, get_reload_paths())),
     )
 
 
@@ -310,8 +346,7 @@ def run_granian_backend(host: str, port: int, loglevel: LogLevel):
             interface=Interfaces.ASGI,
             log_level=LogLevels(loglevel.value),
             reload=True,
-            reload_paths=get_reload_dirs(),
-            reload_ignore_dirs=[".web", ".states"],
+            reload_paths=get_reload_paths(),
         ).serve()
     except ImportError:
         console.error(

tests/units/test_config.py

@@ -252,6 +252,7 @@ def test_env_var():
         BLUBB: EnvVar[str] = env_var("default")
         INTERNAL: EnvVar[str] = env_var("default", internal=True)
         BOOLEAN: EnvVar[bool] = env_var(False)
+        LIST: EnvVar[list[int]] = env_var([1, 2, 3])
 
     assert TestEnv.BLUBB.get() == "default"
     assert TestEnv.BLUBB.name == "BLUBB"
@@ -280,3 +281,11 @@ def test_env_var():
     assert TestEnv.BOOLEAN.get() is False
     TestEnv.BOOLEAN.set(None)
     assert "BOOLEAN" not in os.environ
+
+    assert TestEnv.LIST.get() == [1, 2, 3]
+    assert TestEnv.LIST.name == "LIST"
+    TestEnv.LIST.set([4, 5, 6])
+    assert os.environ.get("LIST") == "4:5:6"
+    assert TestEnv.LIST.get() == [4, 5, 6]
+    TestEnv.LIST.set(None)
+    assert "LIST" not in os.environ