support Path in Config (#755)

* support Path in Config

* fix broken tests

starlette/config.py

@@ -1,6 +1,7 @@
 import os
 import typing
 from collections.abc import MutableMapping
+from pathlib import Path
 
 
 class undefined:
@@ -46,7 +47,9 @@ environ = Environ()
 
 class Config:
     def __init__(
-        self, env_file: str = None, environ: typing.Mapping[str, str] = environ
+        self,
+        env_file: typing.Union[str, Path] = None,
+        environ: typing.Mapping[str, str] = environ,
     ) -> None:
         self.environ = environ
         self.file_values = {}  # type: typing.Dict[str, str]
@@ -71,7 +74,7 @@ class Config:
             return self._perform_cast(key, default, cast)
         raise KeyError(f"Config '{key}' is missing, and has no default.")
 
-    def _read_file(self, file_name: str) -> typing.Dict[str, str]:
+    def _read_file(self, file_name: typing.Union[str, Path]) -> typing.Dict[str, str]:
         file_values = {}  # type: typing.Dict[str, str]
         with open(file_name) as input_file:
             for line in input_file.readlines():

tests/test_config.py

@@ -5,6 +5,8 @@ import pytest
 from starlette.config import Config, Environ, EnvironError
 from starlette.datastructures import URL, Secret
 
+from pathlib import Path
+
 
 def test_config(tmpdir, monkeypatch):
     path = os.path.join(tmpdir, ".env")
@@ -44,6 +46,10 @@ def test_config(tmpdir, monkeypatch):
     with pytest.raises(ValueError):
         config.get("REQUEST_HOSTNAME", cast=bool)
 
+    config = Config(Path(path))
+    REQUEST_HOSTNAME= config("REQUEST_HOSTNAME")
+    assert REQUEST_HOSTNAME == "example.com"
+
     config = Config()
     monkeypatch.setenv("STARLETTE_EXAMPLE_TEST", "123")
     monkeypatch.setenv("BOOL_AS_INT", "1")
@@ -54,7 +60,6 @@ def test_config(tmpdir, monkeypatch):
     with pytest.raises(ValueError):
         config.get("BOOL_AS_INT", cast=bool)
 
-
 def test_environ():
     environ = Environ()