From d6b2c9b15ceec8932755949a7ca8359540494afb Mon Sep 17 00:00:00 2001
From: Stefano Pigozzi <me@steffo.eu>
Date: Tue, 19 Apr 2022 01:32:10 +0200
Subject: [PATCH] :wrench: Split sources into their own namespace package

---
 cfig/__init__.py                    |  2 --
 cfig/config.py                      | 12 +++++----
 cfig/sources/base.py                | 23 ++++++++++++++++
 cfig/{sources.py => sources/env.py} | 41 ++---------------------------
 cfig/sources/envfile.py             | 27 +++++++++++++++++++
 5 files changed, 59 insertions(+), 46 deletions(-)
 create mode 100644 cfig/sources/base.py
 rename cfig/{sources.py => sources/env.py} (51%)
 create mode 100644 cfig/sources/envfile.py

diff --git a/cfig/__init__.py b/cfig/__init__.py
index 196487e..503cd2f 100644
--- a/cfig/__init__.py
+++ b/cfig/__init__.py
@@ -95,8 +95,6 @@ Configuration
 # noinspection PyUnresolvedReferences
 from .config import *
 # noinspection PyUnresolvedReferences
-from .sources import *
-# noinspection PyUnresolvedReferences
 from .errors import *
 # noinspection PyUnresolvedReferences
 from .customtyping import *
diff --git a/cfig/config.py b/cfig/config.py
index ad0ef0e..175c6ad 100644
--- a/cfig/config.py
+++ b/cfig/config.py
@@ -8,7 +8,9 @@ import logging
 import collections
 from . import errors
 from . import customtyping as ct
-from . import sources as s
+from cfig.sources.base import Source
+from cfig.sources.env import EnvironmentSource
+from cfig.sources.envfile import EnvironmentFileSource
 
 log = logging.getLogger(__name__)
 
@@ -19,8 +21,8 @@ class Configuration:
     """
 
     DEFAULT_SOURCES = [
-        s.EnvironmentSource(),
-        s.EnvironmentFileSource(),
+        EnvironmentSource(),
+        EnvironmentFileSource(),
     ]
     """
     The sources used in :meth:`__init__` if no other source is specified.
@@ -73,14 +75,14 @@ class Configuration:
                 log.debug(f"Unresolving: {item!r}")
                 del item.__wrapped__
 
-    def __init__(self, *, sources: t.Optional[t.Collection[s.Source]] = None):
+    def __init__(self, *, sources: t.Optional[t.Collection[Source]] = None):
         """
         Create a new :class:`Configuration`.
         """
 
         log.debug(f"Initializing a new {self.__class__.__qualname__} object...")
 
-        self.sources: t.Collection[s.Source] = sources or self.DEFAULT_SOURCES
+        self.sources: t.Collection[Source] = sources or self.DEFAULT_SOURCES
         """
         Collection of sources to use for values of this configuration.
         """
diff --git a/cfig/sources/base.py b/cfig/sources/base.py
new file mode 100644
index 0000000..bf9dbb6
--- /dev/null
+++ b/cfig/sources/base.py
@@ -0,0 +1,23 @@
+import abc
+import typing as t
+
+
+class Source(metaclass=abc.ABCMeta):
+    """
+    A source of values to be tapped by configurations.
+
+    **Abstract class.** Cannot be instantiated. Should be inherited from other source classes.
+
+    Other packages can add more sources directly to the :mod:`cfig.sources` namespace package.
+    """
+
+    @abc.abstractmethod
+    def get(self, key: str) -> t.Optional[str]:
+        """
+        Get the value with the given key from the source.
+        """
+
+
+__all__ = (
+    "Source",
+)
diff --git a/cfig/sources.py b/cfig/sources/env.py
similarity index 51%
rename from cfig/sources.py
rename to cfig/sources/env.py
index 5247ddb..b47620b 100644
--- a/cfig/sources.py
+++ b/cfig/sources/env.py
@@ -1,18 +1,6 @@
-import typing as t
-import abc
 import os
-
-
-class Source(metaclass=abc.ABCMeta):
-    """
-    A source of values to be tapped by configurations.
-    """
-
-    @abc.abstractmethod
-    def get(self, key: str) -> t.Optional[str]:
-        """
-        Get the value with the given key from the source
-        """
+import typing as t
+from cfig.sources.base import Source
 
 
 class EnvironmentSource(Source):
@@ -49,28 +37,3 @@ class EnvironmentSource(Source):
         key = self._process_key(key)
         return self.environment.get(key)
 
-
-class EnvironmentFileSource(EnvironmentSource):
-    """
-    A source which gets values from files at paths specified in environment variables.
-    """
-
-    def __init__(self, *, prefix: str = "", suffix: str = "_FILE", environment=os.environ):
-        super().__init__(prefix=prefix, suffix=suffix, environment=environment)
-
-    def get(self, key: str) -> t.Optional[str]:
-        path = super().get(key)
-        if path is None:
-            return None
-        try:
-            with open(path, "r") as file:
-                return file.read()
-        except FileNotFoundError:
-            return None
-
-
-__all__ = (
-    "Source",
-    "EnvironmentSource",
-    "EnvironmentFileSource",
-)
diff --git a/cfig/sources/envfile.py b/cfig/sources/envfile.py
new file mode 100644
index 0000000..41a1275
--- /dev/null
+++ b/cfig/sources/envfile.py
@@ -0,0 +1,27 @@
+import os
+import typing as t
+from cfig.sources.env import EnvironmentSource
+
+
+class EnvironmentFileSource(EnvironmentSource):
+    """
+    A source which gets values from files at paths specified in environment variables.
+    """
+
+    def __init__(self, *, prefix: str = "", suffix: str = "_FILE", environment=os.environ):
+        super().__init__(prefix=prefix, suffix=suffix, environment=environment)
+
+    def get(self, key: str) -> t.Optional[str]:
+        path = super().get(key)
+        if path is None:
+            return None
+        try:
+            with open(path, "r") as file:
+                return file.read()
+        except FileNotFoundError:
+            return None
+
+
+__all__ = (
+    "EnvironmentFileSource",
+)