Add support for Unix fd D-Bus type

tests/unittests/Message_test.cpp

@@ -30,6 +30,7 @@
 #include <cstdint>
 
 using ::testing::Eq;
+using ::testing::Gt;
 using ::testing::DoubleEq;
 using namespace std::string_literals;
 
@@ -125,6 +126,21 @@ TEST(AMessage, CanCarryASimpleInteger)
     ASSERT_THAT(dataRead, Eq(dataWritten));
 }
 
+TEST(AMessage, CanCarryAUnixFd)
+{
+    sdbus::Message msg{sdbus::createPlainMessage()};
+
+    sdbus::UnixFd dataWritten = 0;
+    msg << dataWritten;
+
+    msg.seal();
+
+    sdbus::UnixFd dataRead;
+    msg >> dataRead;
+
+    ASSERT_THAT(dataRead, Gt(dataWritten));
+}
+
 TEST(AMessage, CanCarryAVariant)
 {
     sdbus::Message msg{sdbus::createPlainMessage()};

tests/unittests/TypeTraits_test.cpp

@@ -72,6 +72,7 @@ namespace
     TYPE(sdbus::ObjectPath)HAS_DBUS_TYPE_SIGNATURE("o")
     TYPE(sdbus::Signature)HAS_DBUS_TYPE_SIGNATURE("g")
     TYPE(sdbus::Variant)HAS_DBUS_TYPE_SIGNATURE("v")
+    TYPE(sdbus::UnixFd)HAS_DBUS_TYPE_SIGNATURE("h")
     TYPE(sdbus::Struct<bool>)HAS_DBUS_TYPE_SIGNATURE("(b)")
     TYPE(sdbus::Struct<uint16_t, double, std::string, sdbus::Variant>)HAS_DBUS_TYPE_SIGNATURE("(qdsv)")
     TYPE(std::vector<int16_t>)HAS_DBUS_TYPE_SIGNATURE("an")
@@ -91,10 +92,11 @@ namespace
                                     >
                                 >,
                                 sdbus::Signature,
+                                sdbus::UnixFd,
                                 const char*
                             >
                         >;
-    TYPE(ComplexType)HAS_DBUS_TYPE_SIGNATURE("a{t(a{ya(obva{is})}gs)}")
+    TYPE(ComplexType)HAS_DBUS_TYPE_SIGNATURE("a{t(a{ya(obva{is})}ghs)}")
 
     typedef ::testing::Types< bool
                             , uint8_t
@@ -110,6 +112,7 @@ namespace
                             , sdbus::ObjectPath
                             , sdbus::Signature
                             , sdbus::Variant
+                            , sdbus::UnixFd
                             , sdbus::Struct<bool>
                             , sdbus::Struct<uint16_t, double, std::string, sdbus::Variant>
                             , std::vector<int16_t>

tests/unittests/Types_test.cpp

@@ -240,3 +240,10 @@ TEST(ASignature, CanBeConstructedFromStdString)
 
     ASSERT_THAT(sdbus::Signature{aSignature}, Eq(aSignature));
 }
+
+TEST(AUnixFd, CanBeConstructedFromInt)
+{
+    int fd{2};
+
+    ASSERT_THAT((int)sdbus::UnixFd{fd}, Eq(fd));
+}