Fixed errors and improve roster tests

library/include/larra/stream_error.hpp

@@ -145,4 +145,7 @@ using StreamError = std::variant<error::stream::BadFormat,
                                  error::stream::UnsupportedVersion,
                                  error::stream::UnknownXmppError>;
 
+static_assert(!std::is_same_v<typename std::variant_alternative_t<std::variant_size_v<StreamError> - 1, StreamError>, StreamError>,
+              "'UnknownXmppError' must be at the end of 'StreamError' variant");
+
 }  // namespace larra::xmpp

tests/serialization.cpp

@@ -33,12 +33,6 @@ TEST(Serialize, Variant) {
             "xmlns=\"urn:ietf:params:xml:ns:xmpp-streams\"/></stream:error>\n"sv);
 }
 
-TEST(CheckFinalErrorPlace, Variant) {
-  StreamError stream_error = error::stream::UnknownXmppError{};
-  EXPECT_NO_THROW(std::get<std::variant_size_v<StreamError> - 1>(stream_error))
-      << "'UnknownXmppError' must be at the end of 'StreamError' variant";
-}
-
 namespace tests::serialization {
 
 struct SomeStruct {