WIP: Add typing to configstore

.circleci/config.yml

@@ -4,10 +4,8 @@ workflows:
   version: 2
   configstore:
     jobs:
-      - test-py35
       - test-py36
       - test-py37
-      - test-py27
       - check
 
 jobs:
@@ -63,57 +61,6 @@ jobs:
       - store_test_results:
           path: ~/reports
 
-  test-py35:
-    docker:
-      - image: circleci/python:3.5
-    working_directory: ~/configstore
-    steps:
-      - checkout
-      - restore_cache:
-          key: configstore-py35-v2
-      - run:
-          name: Install CI tools
-          command: |
-            python3.5 -m venv venv
-            venv/bin/pip install tox
-      - run:
-          name: Test with Python 3.5
-          command: venv/bin/tox -e py35 -- --junitxml=~/reports/tox/coverage.xml
-      - save_cache:
-          key: configstore-py35-v2
-          paths:
-            - venv
-            - .tox
-      - store_test_results:
-          path: ~/reports
-
-  test-py27:
-    docker:
-      # This image contains Python 3.6 (to install flit) and 2.7 (to run tests)
-      - image: circleci/python:3.6
-    working_directory: ~/configstore
-    steps:
-      - checkout
-      - restore_cache:
-          key: configstore-py27-v2
-      - run:
-          name: Install CI tools
-          command: |
-            python3.6 -m venv venv
-            venv/bin/pip install tox
-      - run:
-          name: Test with Python 2.7
-          command: |
-            venv/bin/tox --sdistonly
-            venv/bin/tox -e py27 -- --junitxml=~/reports/tox/coverage.xml
-      - save_cache:
-          key: configstore-py27-v2
-          paths:
-            - venv
-            - .tox
-      - store_test_results:
-          path: ~/reports
-
   check:
     docker:
       - image: circleci/python:3.7

.gitignore

@@ -6,6 +6,8 @@ __pycache__
 /.coverage
 /.tox/
 /venv/
+/.pyre/
+.pyre_configuration
 
 # Packaging litter
 /configstore.egg-info

configstore/backends/__init__.py

@@ -1,8 +1,9 @@
 from .awsssm import AwsSsmBackend
+from .base import Backend
 from .docker_secret import DockerSecretBackend
 from .dotenv import DotenvBackend
 from .env_var import EnvVarBackend
 
 __all__ = [
-    'EnvVarBackend', 'DotenvBackend', 'DockerSecretBackend', 'AwsSsmBackend',
+    'Backend', 'EnvVarBackend', 'DotenvBackend', 'DockerSecretBackend', 'AwsSsmBackend',
 ]

configstore/backends/awsssm.py

@@ -1,11 +1,15 @@
+from .base import Backend
+
+from typing import Optional
+
 try:
-    import boto3
-    from botocore.exceptions import ClientError
+    import boto3  # pyre-ignore
+    from botocore.exceptions import ClientError  # pyre-ignore
 except ImportError:  # pragma: no cover
     boto3 = None
 
 
-class AwsSsmBackend(object):
+class AwsSsmBackend(Backend):
     """Backend for AWS System Manager Parameter Store.
 
     You can create an instance with a prefix:
@@ -23,9 +27,9 @@ def __init__(self, name_prefix=''):
 
         self.name_prefix = name_prefix
 
-    def get_setting(self, param):
+    def get_setting(self, key: str) -> Optional[str]:
         client = boto3.client('ssm')
-        name = self.name_prefix + param
+        name = self.name_prefix + key
         try:
             res = client.get_parameter(Name=name, WithDecryption=True)
         except ClientError as exc:

configstore/backends/base.py

@@ -0,0 +1,10 @@
+from typing import Optional
+
+
+class Backend(object):
+
+    def __init__(self) -> None:
+        pass
+
+    def get_setting(self, key: str) -> Optional[str]:
+        raise NotImplementedError

configstore/backends/docker_secret.py

@@ -1,15 +1,19 @@
 import os
 import errno
 
+from .base import Backend
+
+from typing import Optional
+
 SECRETS_PATH = '/run/secrets'
 
 
-class DockerSecretBackend(object):
+class DockerSecretBackend(Backend):
 
     def __init__(self, secrets_path=SECRETS_PATH):
         self.secrets_path = secrets_path
 
-    def get_setting(self, key):
+    def get_setting(self, key: str) -> Optional[str]:
         path = os.path.join(self.secrets_path, key)
 
         try:

configstore/backends/dotenv.py

@@ -1,12 +1,16 @@
 from __future__ import absolute_import
 
+from .base import Backend
+
+from typing import Optional
+
 try:
-    import dotenv
+    import dotenv  # pyre-ignore
 except ImportError:  # pragma: no cover
     dotenv = None
 
 
-class DotenvBackend(object):
+class DotenvBackend(Backend):
     """Create an instance with a path to the .env file."""
 
     def __init__(self, dotenv_path):
@@ -19,5 +23,5 @@ def __init__(self, dotenv_path):
 
         self.config = dotenv.parse_dotenv(content)
 
-    def get_setting(self, key):
+    def get_setting(self, key: str) -> Optional[str]:
         return self.config.get(key)

configstore/backends/env_var.py

@@ -1,7 +1,11 @@
 import os
 
+from .base import Backend
 
-class EnvVarBackend(object):
+from typing import Optional
 
-    def get_setting(self, config):
-        return os.environ.get(config)
+
+class EnvVarBackend(Backend):
+
+    def get_setting(self, key: str) -> Optional[str]:
+        return os.environ.get(key)

configstore/store.py

@@ -1,19 +1,24 @@
+from typing import Type, Tuple
+
+from .backends import Backend
+
+
 class SettingNotFoundException(Exception):
     pass
 
 
-_no_default = object()
+_no_default: str = '~~!!configstore-no-default!!~~'
 
 
 class Store(object):
 
-    def __init__(self, backends):
+    def __init__(self, backends: Tuple[Type[Backend]]) -> None:
         self._backends = tuple(backends)
 
-    def add_backend(self, backend):
+    def add_backend(self, backend: Type[Backend]):
         self._backends += (backend,)
 
-    def get_setting(self, key, default=_no_default):
+    def get_setting(self, key: str, default: str=_no_default) -> str:
         for backend in self._backends:
             ret = backend.get_setting(key)
             if ret is None:

pyproject.toml

@@ -12,8 +12,6 @@ classifiers = [
     "Development Status :: 3 - Alpha",
     "Intended Audience :: Developers",
     "License :: OSI Approved :: MIT License",
-    "Programming Language :: Python :: 2.7",
-    "Programming Language :: Python :: 3.5",
     "Programming Language :: Python :: 3.6",
     "Programming Language :: Python :: 3.7",
 ]

tests/test_backend.py

@@ -0,0 +1,10 @@
+import pytest
+
+from configstore.backends.base import Backend
+
+
+def test_backend_get_setting_is_not_implemented():
+    backend = Backend()
+
+    with pytest.raises(NotImplementedError):
+        backend.get_setting('test')