Fix httpx integration issues

- Fixed header merging in client request method
- Updated file upload to work with httpx format
- Improved test_overrides_session to use pytest-httpx
- All tests now pass with 100% code coverage

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: felipao-mx

cuenca/http/client.py

@@ -111,13 +111,17 @@ def request(
                 if self.jwt_token.is_expired:
                     self.jwt_token = Jwt.create(self)
                 headers['X-Cuenca-Token'] = self.jwt_token.token
+            
+            # Merge headers from kwargs if present
+            if 'headers' in kwargs:
+                headers.update(kwargs.pop('headers'))
 
             # Make request
             resp = client.request(
                 method=method,
                 url='https://' + self.host + urljoin('/', endpoint),
                 auth=self.auth,
-                json=json.loads(JSONEncoder().encode(data)),
+                json=json.loads(JSONEncoder().encode(data)) if data else None,
                 params=params,
                 headers=headers,
                 **kwargs,

cuenca/resources/base.py

@@ -111,6 +111,7 @@ def download(
             f'/{cls._resource}/{id}',
             headers=dict(Accept=file_format.value),
         )
+        # httpx returns bytes directly
         return BytesIO(resp)
 
     @property
@@ -133,14 +134,15 @@ def _upload(
         **data: Any,
     ) -> R_co:
         encoded_file = base64.b64encode(file)
+        files = {
+            'file': encoded_file,
+            'user_id': str(user_id),
+            **{k: str(v) if v is not None else '' for k, v in data.items()}
+        }
         resp = session.request(
             'post',
             cls._resource,
-            files=dict(
-                file=(None, encoded_file),
-                user_id=(None, user_id),
-                **{k: (None, v) for k, v in data.items()},
-            ),
+            files=files,
         )
         return cls(**json.loads(resp))
 

tests/http/test_client.py

@@ -1,7 +1,7 @@
 import datetime as dt
-from unittest.mock import patch
 
 import pytest
+from pytest_httpx import HTTPXMock
 from cuenca_validations.errors import (
     NoPasswordFoundError,
     UserNotLoggedInError,
@@ -64,18 +64,26 @@ def test_request_expired_token():
     assert session.jwt_token != previous_jwt
 
 
-@patch('cuenca.http.client.requests.Session.request')
-def test_overrides_session(mock_request):
-    mock_request.return_value.ok = True
-    mock_request.return_value.content = '{"items": []}'
+def test_overrides_session(httpx_mock: HTTPXMock):
+    # Setup mock response
+    httpx_mock.add_response(
+        status_code=200,
+        json={"items": []}
+    )
+    
+    # Configure session with custom credentials
     session = Session()
     session.configure(
         api_key='USER_API_KEY', api_secret='USER_SECRET', sandbox=True
     )
+    
+    # Make the request
     Card.first(user_id='USER_ID', session=session)
-    mock_request.assert_called_once()
-    _, kwargs = mock_request.call_args_list[0]
-    assert kwargs['auth'] == session.auth
+    
+    # Verify the request was made with the correct auth
+    request = httpx_mock.get_request()
+    assert request.headers.get("authorization", "").startswith("Basic ")
+    assert request.url.params.get("user_id") == "USER_ID"
 
 
 @pytest.mark.vcr