LibWebView+WebContent: Allow setting the default time zone

This is used by tests to set the default time zone to UTC.

This is because certain tests create JavaScript Date objects, which are
in the current timezone.

Libraries/LibWebView/Application.cpp

@@ -109,6 +109,7 @@ ErrorOr<void> Application::initialize(Main::Arguments const& arguments)
     Optional<StringView> webdriver_content_ipc_path;
     Optional<StringView> user_agent_preset;
     Optional<StringView> dns_server_address;
+    Optional<StringView> default_time_zone;
     Optional<u16> dns_server_port;
     bool use_dns_over_tls = false;
     bool layout_test_mode = false;
@@ -178,6 +179,7 @@ ErrorOr<void> Application::initialize(Main::Arguments const& arguments)
     args_parser.add_option(dns_server_port, "Set the DNS server port", "dns-port", 0, "port (default: 53 or 853 if --dot)");
     args_parser.add_option(use_dns_over_tls, "Use DNS over TLS", "dot");
     args_parser.add_option(validate_dnssec_locally, "Validate DNSSEC locally", "dnssec");
+    args_parser.add_option(default_time_zone, "Default time zone", "default-time-zone", 0, "time-zone-id");
 
     args_parser.add_option(Core::ArgsParser::Option {
         .argument_mode = Core::ArgsParser::OptionArgumentMode::Optional,
@@ -276,6 +278,7 @@ ErrorOr<void> Application::initialize(Main::Arguments const& arguments)
         .enable_autoplay = enable_autoplay ? EnableAutoplay::Yes : EnableAutoplay::No,
         .collect_garbage_on_every_allocation = collect_garbage_on_every_allocation ? CollectGarbageOnEveryAllocation::Yes : CollectGarbageOnEveryAllocation::No,
         .paint_viewport_scrollbars = disable_scrollbar_painting ? PaintViewportScrollbars::No : PaintViewportScrollbars::Yes,
+        .default_time_zone = default_time_zone,
     };
 
     create_platform_options(m_browser_options, m_web_content_options);

Libraries/LibWebView/HelperProcess.cpp

@@ -128,6 +128,11 @@ static ErrorOr<NonnullRefPtr<WebView::WebContentClient>> launch_web_content_proc
         arguments.append(ByteString::number(maybe_echo_server_port.value()));
     }
 
+    if (web_content_options.default_time_zone.has_value()) {
+        arguments.append("--default-time-zone");
+        arguments.append(web_content_options.default_time_zone.value());
+    }
+
     if (auto server = mach_server_name(); server.has_value()) {
         arguments.append("--mach-server-name"sv);
         arguments.append(server.value());

Libraries/LibWebView/Options.h

@@ -169,6 +169,7 @@ struct WebContentOptions {
     CollectGarbageOnEveryAllocation collect_garbage_on_every_allocation { CollectGarbageOnEveryAllocation::No };
     Optional<u16> echo_server_port {};
     PaintViewportScrollbars paint_viewport_scrollbars { PaintViewportScrollbars::Yes };
+    Optional<StringView> default_time_zone {};
 };
 
 }

Meta/WPT.sh

@@ -85,6 +85,7 @@ WPT_ARGS=(
     "--webdriver-binary=${WEBDRIVER_BINARY}"
     "--install-webdriver"
     "--webdriver-arg=--force-cpu-painting"
+    "--webdriver-arg=--default-time-zone=UTC"
     "--no-pause-after-test"
     "--install-fonts"
     "${EXTRA_WPT_ARGS[@]}"

Services/WebContent/main.cpp

@@ -18,6 +18,7 @@
 #include <LibMain/Main.h>
 #include <LibMedia/Audio/Loader.h>
 #include <LibRequests/RequestClient.h>
+#include <LibUnicode/TimeZone.h>
 #include <LibWeb/Bindings/MainThreadVM.h>
 #include <LibWeb/Fetch/Fetching/Fetching.h>
 #include <LibWeb/HTML/Window.h>
@@ -107,6 +108,7 @@ ErrorOr<int> ladybird_main(Main::Arguments arguments)
     bool is_headless = false;
     bool disable_scrollbar_painting = false;
     StringView echo_server_port_string_view {};
+    StringView default_time_zone {};
 
     Core::ArgsParser args_parser;
     args_parser.add_option(command_line, "Browser process command line", "command-line", 0, "command_line");
@@ -129,6 +131,7 @@ ErrorOr<int> ladybird_main(Main::Arguments arguments)
     args_parser.add_option(disable_scrollbar_painting, "Don't paint horizontal or vertical viewport scrollbars", "disable-scrollbar-painting");
     args_parser.add_option(echo_server_port_string_view, "Echo server port used in test internals", "echo-server-port", 0, "echo_server_port");
     args_parser.add_option(is_headless, "Report that the browser is running in headless mode", "headless");
+    args_parser.add_option(default_time_zone, "Default time zone", "default-time-zone", 0, "time-zone-id");
 
     args_parser.parse(arguments);
 
@@ -136,6 +139,11 @@ ErrorOr<int> ladybird_main(Main::Arguments arguments)
         Core::Process::wait_for_debugger_and_break();
     }
 
+    if (!default_time_zone.is_empty()) {
+        if (auto result = Unicode::set_current_time_zone(default_time_zone); result.is_error())
+            dbgln("Failed to set default time zone: {}", result.error());
+    }
+
     auto& font_provider = static_cast<Gfx::PathFontProvider&>(Gfx::FontDatabase::the().install_system_font_provider(make<Gfx::PathFontProvider>()));
     if (force_fontconfig) {
         font_provider.set_name_but_fixme_should_create_custom_system_font_provider("FontConfig"_string);

Services/WebDriver/main.cpp

@@ -33,7 +33,7 @@ static ErrorOr<Core::Process> launch_process(StringView application, ReadonlySpa
     return result;
 }
 
-static Vector<ByteString> create_arguments(ByteString const& socket_path, bool headless, bool force_cpu_painting, Optional<StringView> debug_process)
+static Vector<ByteString> create_arguments(ByteString const& socket_path, bool headless, bool force_cpu_painting, Optional<StringView> debug_process, Optional<StringView> default_time_zone)
 {
     Vector<ByteString> arguments {
         "--webdriver-content-path"sv,
@@ -59,6 +59,9 @@ static Vector<ByteString> create_arguments(ByteString const& socket_path, bool h
     if (debug_process.has_value())
         arguments.append(ByteString::formatted("--debug-process={}", debug_process.value()));
 
+    if (default_time_zone.has_value())
+        arguments.append(ByteString::formatted("--default-time-zone={}", default_time_zone.value()));
+
     // FIXME: WebDriver does not yet handle the WebContent process switch brought by site isolation.
     arguments.append("--disable-site-isolation"sv);
 
@@ -75,6 +78,7 @@ ErrorOr<int> ladybird_main(Main::Arguments arguments)
     bool force_cpu_painting = false;
     bool headless = false;
     Optional<StringView> debug_process;
+    Optional<StringView> default_time_zone;
 
     Core::ArgsParser args_parser;
     args_parser.add_option(listen_address, "IP address to listen on", "listen-address", 'l', "listen_address");
@@ -83,6 +87,7 @@ ErrorOr<int> ladybird_main(Main::Arguments arguments)
     args_parser.add_option(force_cpu_painting, "Launch browser with GPU painting disabled", "force-cpu-painting");
     args_parser.add_option(debug_process, "Wait for a debugger to attach to the given process name (WebContent, RequestServer, etc.)", "debug-process", 0, "process-name");
     args_parser.add_option(headless, "Launch browser without a graphical interface", "headless");
+    args_parser.add_option(default_time_zone, "Default time zone", "default-time-zone", 0, "time-zone-id");
     args_parser.parse(arguments);
 
     auto ipv4_address = IPv4Address::from_string(listen_address);
@@ -123,7 +128,7 @@ ErrorOr<int> ladybird_main(Main::Arguments arguments)
         }
 
         auto launch_browser_callback = [&](ByteString const& socket_path, bool headless) {
-            auto arguments = create_arguments(socket_path, headless, force_cpu_painting, debug_process);
+            auto arguments = create_arguments(socket_path, headless, force_cpu_painting, debug_process, default_time_zone);
             return launch_process("Ladybird"sv, arguments.span());
         };
 

Tests/LibWeb/test-web/Application.cpp

@@ -73,6 +73,9 @@ void Application::create_platform_options(WebView::BrowserOptions& browser_optio
     // Ensure tests are resilient to minor changes to the viewport scrollbar.
     web_content_options.paint_viewport_scrollbars = WebView::PaintViewportScrollbars::No;
 
+    // Ensure consistent time zone operations across different machine configurations.
+    web_content_options.default_time_zone = "UTC"sv;
+
     if (dump_gc_graph) {
         // Force all tests to run in serial if we are interested in the GC graph.
         test_concurrency = 1;