Add default headers support

README.rst

@@ -38,6 +38,9 @@ Some useful config keys (all of which are prefixed with
 
 -  ``POPGET_CLIENT_DEFAULT_USER_AGENT`` when making requests, popget will use this
    string as the user agent.
+-  ``POPGET_CLIENT_DEFAULT_HEADERS`` when making requests, popget will add these
+   headers by default to the request, but they can still be overridden when set
+   explicitly.
 -  ``POPGET_CLIENT_TIMEOUT`` if ``None`` then no timeout, otherwise this timeout
    (in seconds) will be applied to all requests. Requests which timeout will
    return a 504 response, which will be raised as an ``HTTPError``.

popget/__about__.py

@@ -1 +1 @@
-__version__ = '2.0.0'
+__version__ = '2.1.0'

popget/client.py

@@ -126,6 +126,7 @@ def __init__(self, config):
     def session(self) -> requests.Session:
         if not self._session:
             session = self.session_cls()
+            session.headers.update(settings.CLIENT_DEFAULT_HEADERS)
             session.headers['User-Agent'] = settings.CLIENT_DEFAULT_USER_AGENT
             self._session = session
         return self._session

popget/conf/settings.py

@@ -9,6 +9,10 @@
     settings, 'POPGET_CLIENT_DEFAULT_USER_AGENT', 'popget/{}'.format(__version__)
 )
 
+CLIENT_DEFAULT_HEADERS: dict[str, str] = getattr(
+    settings, 'POPGET_CLIENT_DEFAULT_HEADERS', {}
+)
+
 CLIENT_TIMEOUT: float = getattr(settings, 'POPGET_CLIENT_TIMEOUT', 3.0)
 
 CLIENT_DISABLE_VERIFY_SSL: bool = getattr(settings, 'POPGET_CLIENT_DISABLE_VERIFY_SSL', False)

tests/test_client.py

@@ -167,6 +167,31 @@ def test_request_header_args_ok():
     }
     assert endpoint.required_args == {'user_id', 'token', 'edition'}
 
+@responses.activate
+def test_default_request_header_ok():
+    """
+    Default request-header are present.
+    """
+    with (
+        patch(
+            'popget.client.settings.CLIENT_DEFAULT_HEADERS',
+            {'Accept-Encoding': 'gzip', 'X-Depop-Pointless': 'default'}
+        )
+    ):
+        def callback(request):
+            assert 'Accept-Encoding' in request.headers
+            assert 'gzip' in request.headers['Accept-Encoding']
+            assert 'X-Depop-Pointless' in request.headers
+            assert 'explicitly pointless' in request.headers['X-Depop-Pointless']
+
+            return (200, {}, '{"thing": "it\'s a thing"}')
+
+        responses.add_callback(responses.GET, 'http://example.com/v1/thing/777',
+                               callback=callback,
+                               content_type='application/json')
+
+        data = DummyService.thing_detail(id=777)
+        assert len(responses.calls) == 1
 
 def test_request_header_args_clash():
     """
@@ -230,6 +255,9 @@ class Config:
     thing_detail = APIEndpoint(
         'GET',
         '/v1/thing/{id}',
+        request_headers={
+            'X-Depop-Pointless': 'explicitly pointless',
+        }
     )
     thing_update = APIEndpoint(
         'PATCH',