LibDNS: Add basic DNS::Resolver tests

Author: https://github.com/devgianlu
Commit: https://github.com/LadybirdBrowser/ladybird/commit/0926720c2af
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/3611
Reviewed-by: https://github.com/alimpfard ✅

Meta/Lagom/CMakeLists.txt

@@ -512,6 +512,7 @@ if (BUILD_TESTING)
         AK
         LibCrypto
         LibCompress
+        LibDNS
         LibGC
         LibTest
         LibTextCodec

Tests/CMakeLists.txt

@@ -2,6 +2,7 @@ add_subdirectory(AK)
 add_subdirectory(LibCompress)
 add_subdirectory(LibCore)
 add_subdirectory(LibDiff)
+add_subdirectory(LibDNS)
 add_subdirectory(LibGfx)
 add_subdirectory(LibJS)
 add_subdirectory(LibRegex)

Tests/LibDNS/CMakeLists.txt

@@ -0,0 +1,7 @@
+set(TEST_SOURCES
+    TestDNSResolver.cpp
+)
+
+foreach(source IN LISTS TEST_SOURCES)
+    serenity_test("${source}" LibDNS LIBS LibDNS LibTLS)
+endforeach()

Tests/LibDNS/TestDNSResolver.cpp

@@ -0,0 +1,115 @@
+/*
+ * Copyright (c) 2025, Altomani Gianluca <altomanigianluca@gmail.com>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <LibCore/Socket.h>
+#include <LibDNS/Resolver.h>
+#include <LibFileSystem/FileSystem.h>
+#include <LibTLS/TLSv12.h>
+#include <LibTest/TestCase.h>
+
+TEST_CASE(test_udp)
+{
+    Core::EventLoop loop;
+
+    DNS::Resolver resolver {
+        [&] -> ErrorOr<DNS::Resolver::SocketResult> {
+            Core::SocketAddress addr = { IPv4Address::from_string("1.1.1.1"sv).value(), static_cast<u16>(53) };
+            return DNS::Resolver::SocketResult {
+                MUST(Core::BufferedSocket<Core::UDPSocket>::create(MUST(Core::UDPSocket::connect(addr)))),
+                DNS::Resolver::ConnectionMode::UDP,
+            };
+        }
+    };
+
+    MUST(resolver.when_socket_ready()->await());
+
+    resolver.lookup("google.com", DNS::Messages::Class::IN, { DNS::Messages::ResourceType::A, DNS::Messages::ResourceType::AAAA })
+        ->when_resolved([&](auto& result) {
+            EXPECT(!result->records().is_empty());
+            loop.quit(0);
+        })
+        .when_rejected([&](auto& error) {
+            outln("Failed to resolve: {}", error);
+            loop.quit(1);
+        });
+
+    EXPECT_EQ(0, loop.exec());
+}
+
+TEST_CASE(test_tcp)
+{
+    Core::EventLoop loop;
+
+    DNS::Resolver resolver {
+        [&] -> ErrorOr<DNS::Resolver::SocketResult> {
+            Core::SocketAddress addr = { IPv4Address::from_string("1.1.1.1"sv).value(), static_cast<u16>(53) };
+            return DNS::Resolver::SocketResult {
+                MUST(Core::BufferedSocket<Core::TCPSocket>::create(MUST(Core::TCPSocket::connect(addr)))),
+                DNS::Resolver::ConnectionMode::TCP,
+            };
+        }
+    };
+
+    MUST(resolver.when_socket_ready()->await());
+
+    resolver.lookup("google.com", DNS::Messages::Class::IN, { DNS::Messages::ResourceType::A, DNS::Messages::ResourceType::AAAA })
+        ->when_resolved([&](auto& result) {
+            EXPECT(!result->records().is_empty());
+            loop.quit(0);
+        })
+        .when_rejected([&](auto& error) {
+            outln("Failed to resolve: {}", error);
+            loop.quit(1);
+        });
+
+    EXPECT_EQ(0, loop.exec());
+}
+
+static StringView ca_certs_file = "./cacert.pem"sv;
+static Optional<ByteString> locate_ca_certs_file()
+{
+    if (FileSystem::exists(ca_certs_file)) {
+        return ca_certs_file;
+    }
+    auto on_target_path = ByteString("/etc/cacert.pem");
+    if (FileSystem::exists(on_target_path)) {
+        return on_target_path;
+    }
+    return {};
+}
+
+TEST_CASE(test_tls)
+{
+    Core::EventLoop loop;
+
+    DNS::Resolver resolver {
+        [&] -> ErrorOr<DNS::Resolver::SocketResult> {
+            Core::SocketAddress addr = { IPv4Address::from_string("1.1.1.1"sv).value(), static_cast<u16>(853) };
+
+            TLS::Options options;
+            options.set_root_certificates_path(locate_ca_certs_file());
+
+            return DNS::Resolver::SocketResult {
+                MaybeOwned<Core::Socket>(TRY(TLS::TLSv12::connect(addr, "1.1.1.1", move(options)))),
+                DNS::Resolver::ConnectionMode::TCP,
+            };
+        }
+    };
+
+    MUST(resolver.when_socket_ready()->await());
+
+    resolver.lookup("google.com", DNS::Messages::Class::IN, { DNS::Messages::ResourceType::A, DNS::Messages::ResourceType::AAAA })
+        ->when_resolved([&](auto& result) {
+            EXPECT(!result->records().is_empty());
+            loop.quit(0);
+        })
+        .when_rejected([&](auto& error) {
+            outln("Failed to resolve: {}", error);
+            loop.quit(1);
+        });
+
+    EXPECT_EQ(0, loop.exec());
+}