Allow client-wide configuration of the testmode variable

mollie/api/client.py

@@ -53,6 +53,7 @@ class Client(object):
     client_id: str = ""
     client_secret: str = ""
     set_token: Callable[[dict], None]
+    testmode: bool = False
 
     @staticmethod
     def validate_api_endpoint(api_endpoint: str) -> str:
@@ -126,6 +127,9 @@ def set_access_token(self, access_token: str) -> None:
     def set_timeout(self, timeout: Union[int, Tuple[int, int]]) -> None:
         self.timeout = timeout
 
+    def set_testmode(self, testmode: bool) -> None:
+        self.testmode = testmode
+
     def set_user_agent_component(self, key: str, value: str, sanitize: bool = True) -> None:
         """Add or replace new user-agent component strings.
 
@@ -167,6 +171,13 @@ def _format_request_data(
             except TypeError as err:
                 raise RequestSetupError(f"Error encoding data into JSON: {err}.")
 
+        if params is None:
+            params = {}
+        if self.testmode and "testmode" not in params:
+            if not (self.api_key.startswith("access_") or hasattr(self, "_oauth_client")):
+                raise RequestSetupError("Configuring testmode only works with access_token or OAuth authorization")
+            params["testmode"] = "true"
+
         querystring = generate_querystring(params)
         if querystring:
             url += "?" + querystring

tests/test_api_client.py

@@ -430,3 +430,46 @@ def test_unauthorized_oauth_client_should_return_authorization_url(mocker, respo
     assert authorization_url.startswith(
         client.OAUTH_AUTHORIZATION_URL
     ), "A client without initial token should return a correct authorization url"
+
+
+def test_enable_testmode_globally_access_token(response):
+    mocked_request = response.get(
+        "https://api.mollie.com/v2/methods", "methods_list", match=[matchers.query_string_matcher("testmode=true")]
+    )
+
+    client = Client()
+    client.set_access_token("access_123")
+    client.set_testmode(True)
+
+    client.methods.list()
+    assert mocked_request.call_count == 1
+
+
+def test_enable_testmode_globally_oauth(response, oauth_client):
+    mocked_request = response.get(
+        "https://api.mollie.com/v2/methods", "methods_list", match=[matchers.query_string_matcher("testmode=true")]
+    )
+
+    oauth_client.set_testmode(True)
+
+    oauth_client.methods.list()
+    assert mocked_request.call_count == 1
+
+
+def test_override_testmode(response, oauth_client):
+    mocked_request = response.get(
+        "https://api.mollie.com/v2/methods", "methods_list", match=[matchers.query_string_matcher("testmode=false")]
+    )
+
+    oauth_client.set_testmode(True)
+
+    oauth_client.methods.list(testmode="false")
+    assert mocked_request.call_count == 1
+
+
+def test_testmode_for_apikey_access_raises_error(client, response):
+    client.set_testmode(True)
+
+    with pytest.raises(RequestSetupError) as excinfo:
+        client.methods.list()
+    assert str(excinfo.value) == "Configuring testmode only works with access_token or OAuth authorization"