Add 'dry_mode' parameter (#382)

Author: leplatrem

README.rst

@@ -80,6 +80,15 @@ An asynchronous client is also available. It has all the same endpoints as the s
     info = await client.server_info()
     assert 'schema' in info['capabilities'], "Server doesn't support schema validation."
 
+
+Dry Mode
+--------
+
+The ``dry_mode`` parameter can be set to simulate requests without actually sending them over the network.
+When enabled, dry mode ensures that no external calls are made, making it useful for testing or debugging.
+Instead of performing real HTTP operations, the client logs the requests with ``DEBUG`` level.
+
+
 Using a Bearer access token to authenticate (OpenID)
 ----------------------------------------------------
 

src/kinto_http/batch.py

@@ -79,6 +79,10 @@ def send(self):
                 method="POST", endpoint=self.endpoints.get("batch"), payload={"requests": chunk}
             )
             resp, headers = self.session.request(**kwargs)
+            if self.session.dry_mode:
+                resp.setdefault(
+                    "responses", [{"status": 200, "body": {}} for i in range(len(chunk))]
+                )
             for i, response in enumerate(resp["responses"]):
                 status_code = response["status"]
 

src/kinto_http/client.py

@@ -46,6 +46,7 @@ def __init__(
         timeout=None,
         ignore_batch_4xx=False,
         headers=None,
+        dry_mode=False,
     ):
         self.endpoints = Endpoints()
 
@@ -63,6 +64,7 @@ def __init__(
             retry_after=retry_after,
             timeout=timeout,
             headers=headers,
+            dry_mode=dry_mode,
         )
         self.session = create_session(**session_kwargs)
         self.bucket_name = bucket
@@ -88,9 +90,11 @@ def clone(self, **kwargs):
     def batch(self, **kwargs):
         if self._server_settings is None:
             resp, _ = self.session.request("GET", self._get_endpoint("root"))
-            self._server_settings = resp["settings"]
+            self._server_settings = resp["settings"] if not self.session.dry_mode else {}
 
-        batch_max_requests = self._server_settings["batch_max_requests"]
+        batch_max_requests = (
+            self._server_settings["batch_max_requests"] if not self.session.dry_mode else 999999
+        )
         batch_session = BatchSession(
             self, batch_max_requests=batch_max_requests, ignore_4xx_errors=self._ignore_batch_4xx
         )

src/kinto_http/session.py

@@ -1,16 +1,21 @@
 import json
+import logging
 import time
 import warnings
-from urllib.parse import urlparse
+from urllib.parse import urlencode, urlparse
 
 import requests
+from urllib3.response import HTTPResponse
 
 import kinto_http
 from kinto_http import utils
 from kinto_http.constants import USER_AGENT
 from kinto_http.exceptions import BackoffException, KintoException
 
 
+logger = logging.getLogger(__name__)
+
+
 def create_session(server_url=None, auth=None, session=None, **kwargs):
     """Returns a session from the passed arguments.
 
@@ -55,7 +60,14 @@ class Session(object):
     """Handles all the interactions with the network."""
 
     def __init__(
-        self, server_url, auth=None, timeout=False, headers=None, retry=0, retry_after=None
+        self,
+        server_url,
+        auth=None,
+        timeout=False,
+        headers=None,
+        retry=0,
+        retry_after=None,
+        dry_mode=False,
     ):
         self.backoff = None
         self.server_url = server_url
@@ -64,6 +76,7 @@ def __init__(
         self.retry_after = retry_after
         self.timeout = timeout
         self.headers = headers or {}
+        self.dry_mode = dry_mode
 
     def request(self, method, endpoint, data=None, permissions=None, payload=None, **kwargs):
         current_time = time.time()
@@ -123,7 +136,15 @@ def request(self, method, endpoint, data=None, permissions=None, payload=None, *
 
         retry = self.nb_retry
         while retry >= 0:
-            resp = requests.request(method, actual_url, **kwargs)
+            if self.dry_mode:
+                qs = ("?" + urlencode(kwargs["params"])) if "params" in kwargs else ""
+                logger.debug(f"(dry mode) {method} {actual_url}{qs}")
+                resp = HTTPResponse(
+                    status=200, headers={"Content-Type": "application/json"}, body=b"{}"
+                )
+                resp.status_code = resp.status
+            else:
+                resp = requests.request(method, actual_url, **kwargs)
 
             if "Alert" in resp.headers:
                 warnings.warn(resp.headers["Alert"], DeprecationWarning)

tests/conftest.py

@@ -16,34 +16,37 @@
 
 
 @pytest.fixture
-def async_client_setup(mocker: MockerFixture) -> AsyncClient:
+def mocked_session(mocker: MockerFixture):
     session = mocker.MagicMock()
-    mock_response(session)
-    client = AsyncClient(session=session, bucket="mybucket")
+    session.dry_mode = False
+    return session
+
+
+@pytest.fixture
+def async_client_setup(mocked_session, mocker: MockerFixture) -> AsyncClient:
+    mock_response(mocked_session)
+    client = AsyncClient(session=mocked_session, bucket="mybucket")
     return client
 
 
 @pytest.fixture
-def client_setup(mocker: MockerFixture) -> Client:
-    session = mocker.MagicMock()
-    mock_response(session)
-    client = Client(session=session, bucket="mybucket")
+def client_setup(mocked_session, mocker: MockerFixture) -> Client:
+    mock_response(mocked_session)
+    client = Client(session=mocked_session, bucket="mybucket")
     return client
 
 
 @pytest.fixture
-def record_async_setup(mocker: MockerFixture) -> AsyncClient:
-    session = mocker.MagicMock()
-    session.request.return_value = (mocker.sentinel.response, mocker.sentinel.count)
-    client = AsyncClient(session=session, bucket="mybucket", collection="mycollection")
+def record_async_setup(mocked_session, mocker: MockerFixture) -> AsyncClient:
+    mocked_session.request.return_value = (mocker.sentinel.response, mocker.sentinel.count)
+    client = AsyncClient(session=mocked_session, bucket="mybucket", collection="mycollection")
     return client
 
 
 @pytest.fixture
-def record_setup(mocker: MockerFixture) -> Client:
-    session = mocker.MagicMock()
-    session.request.return_value = (mocker.sentinel.response, mocker.sentinel.count)
-    client = Client(session=session, bucket="mybucket", collection="mycollection")
+def record_setup(mocked_session, mocker: MockerFixture) -> Client:
+    mocked_session.request.return_value = (mocker.sentinel.response, mocker.sentinel.count)
+    client = Client(session=mocked_session, bucket="mybucket", collection="mycollection")
     return client
 
 
@@ -87,10 +90,11 @@ def endpoints_setup() -> Tuple[Endpoints, Dict]:
 
 
 @pytest.fixture
-def batch_setup(mocker: MockerFixture) -> Client:
-    client = mocker.MagicMock()
+def batch_setup(mocked_session, mocker: MockerFixture) -> Client:
     mocker.sentinel.resp = {"responses": []}
-    client.session.request.return_value = (mocker.sentinel.resp, mocker.sentinel.headers)
+    mocked_session.request.return_value = (mocker.sentinel.resp, mocker.sentinel.headers)
+    client = mocker.MagicMock()
+    client.session = mocked_session
     return client
 
 

tests/test_functional.py

@@ -590,3 +590,16 @@ def test_get_permissions(functional_setup):
 
     perms_by_uri = {p["uri"]: p for p in perms}
     assert set(perms_by_uri["/accounts/user"]["permissions"]) == {"read", "write"}
+
+
+def test_dry_mode(functional_setup):
+    client = functional_setup.clone(server_url="http://not-a-valid-domain:42", dry_mode=True)
+
+    with client.batch() as batch:
+        batch.create_bucket()
+        batch.create_collection(id="cid")
+
+    r1, r2 = batch.results()
+
+    assert r1 == {}
+    assert r2 == {}

tests/test_session.py

@@ -1,3 +1,4 @@
+import logging
 import sys
 import time
 import warnings
@@ -545,3 +546,14 @@ def test_next_request_without_the_header_clear_the_backoff(
     time.sleep(1)  # Spend the backoff
     session.request("get", "/test")  # The second call reset the backoff
     assert session.backoff is None
+
+
+def test_dry_mode_logs_debug(caplog):
+    caplog.set_level(logging.DEBUG)
+
+    session = Session(server_url="https://foo:42", dry_mode=True)
+    body, headers = session.request("GET", "/test", params={"_since": "333"})
+
+    assert body == {}
+    assert headers == {"Content-Type": "application/json"}
+    assert caplog.messages == ["(dry mode) GET https://foo:42/test?_since=333"]