[py]: handle named get_cookie and delete_cookie for None and empty strings (SeleniumHQ#15073)

* handle `None` and empty string case for `get_cookie()` and `delete_cookie()`

* run `format.sh`

* apply suggestion for test cases

---------

Co-authored-by: Viet Nguyen Duc <[email protected]>

Author: 2 people

py/selenium/webdriver/remote/webdriver.py

@@ -715,24 +715,34 @@ def get_cookies(self) -> List[dict]:
         return self.execute(Command.GET_ALL_COOKIES)["value"]
 
     def get_cookie(self, name) -> Optional[Dict]:
-        """Get a single cookie by name. Returns the cookie if found, None if
-        not.
+        """Get a single cookie by name. Raises ValueError if the name is empty
+        or whitespace. Returns the cookie if found, None if not.
 
         Example:
         --------
         >>> cookie = driver.get_cookie('my_cookie')
         """
+        if not name or name.isspace():
+            raise ValueError("Cookie name cannot be empty")
+
         with contextlib.suppress(NoSuchCookieException):
             return self.execute(Command.GET_COOKIE, {"name": name})["value"]
+
         return None
 
     def delete_cookie(self, name) -> None:
-        """Deletes a single cookie with the given name.
+        """Deletes a single cookie with the given name. Raises ValueError if
+        the name is empty or whitespace.
 
         Example:
         --------
         >>> driver.delete_cookie('my_cookie')
         """
+
+        # firefox deletes all cookies when "" is passed as name
+        if not name or name.isspace():
+            raise ValueError("Cookie name cannot be empty")
+
         self.execute(Command.DELETE_COOKIE, {"name": name})
 
     def delete_all_cookies(self) -> None:

py/test/selenium/webdriver/common/cookie_tests.py

@@ -152,3 +152,31 @@ def test_should_not_delete_cookies_with_asimilar_name(cookie, driver, webserver)
     cookies = driver.get_cookies()
     assert cookie["name"] != cookies[0]["name"]
     assert cookie2["name"] == cookies[0]["name"]
+
+
+def test_get_cookie_raises_value_error_for_empty_name(cookie, driver):
+    driver.add_cookie(cookie)
+    with pytest.raises(ValueError, match="Cookie name cannot be empty"):
+        driver.get_cookie("")
+    with pytest.raises(ValueError, match="Cookie name cannot be empty"):
+        driver.get_cookie("   ")
+    with pytest.raises(ValueError, match="Cookie name cannot be empty"):
+        driver.get_cookie(None)
+
+
+def test_delete_cookie_raises_value_error_for_empty_name(cookie, driver):
+    cookie2 = cookie.copy()
+    cookie2["name"] = "{}x".format(cookie["name"])
+    driver.add_cookie(cookie)
+    driver.add_cookie(cookie2)
+
+    with pytest.raises(ValueError, match="Cookie name cannot be empty"):
+        driver.delete_cookie("")
+    with pytest.raises(ValueError, match="Cookie name cannot be empty"):
+        driver.get_cookie("   ")
+    with pytest.raises(ValueError, match="Cookie name cannot be empty"):
+        driver.get_cookie(None)
+
+    cookies = driver.get_cookies()
+
+    assert len(cookies) == 2