WebDriver: Implement DELETE /session/{id}/cookie endpoint

Userland/Services/WebDriver/Session.cpp

@@ -297,4 +297,39 @@ ErrorOr<JsonValue, HttpError> Session::get_named_cookie(String const& name)
     return HttpError { 404, "no such cookie", "Cookie not found" };
 }
 
+// https://w3c.github.io/webdriver/#dfn-delete-cookies
+void Session::delete_cookies(Optional<StringView> const& name)
+{
+    // For each cookie among all associated cookies of the current browsing context’s active document,
+    // run the substeps of the first matching condition:
+    for (auto& cookie : m_browser_connection->get_all_cookies()) {
+        // -> name is undefined
+        // -> name is equal to cookie name
+        if (!name.has_value() || name.value() == cookie.name) {
+            // Set the cookie expiry time to a Unix timestamp in the past.
+            cookie.expiry_time = Core::DateTime::from_timestamp(0);
+            m_browser_connection->async_update_cookie(cookie);
+        }
+        // -> Otherwise
+        //    Do nothing.
+    }
+}
+
+// DELETE /session/{session id}/cookie https://w3c.github.io/webdriver/#dfn-delete-all-cookies
+ErrorOr<JsonValue, HttpError> Session::delete_all_cookies()
+{
+    // 1. If the current browsing context is no longer open, return error with error code no such window.
+    auto current_window = get_window_object();
+    if (!current_window.has_value())
+        return HttpError { 404, "no such window", "Window not found" };
+
+    // FIXME: 2. Handle any user prompts, and return its value if it is an error.
+
+    // 3. Delete cookies, giving no filtering argument.
+    delete_cookies();
+
+    // 4. Return success with data null.
+    return JsonValue();
+}
+
 }