[test] Add test for property system with alias definitions

test/common/propertysystem/CMakeLists.txt

 # build the test for the property system
 dumux_add_test(SOURCES test_propertysystem.cc
               LABELS unit)
+
+dumux_add_test(SOURCES test_propertysystem_aliases.cc
+              LABELS unit)

test/common/propertysystem/test_propertysystem_aliases.cc

+// -*- mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+// vi: set et ts=4 sw=4 sts=4:
+/*****************************************************************************
+ *   See the file COPYING for full copying permissions.                      *
+ *                                                                           *
+ *   This program is free software: you can redistribute it and/or modify    *
+ *   it under the terms of the GNU General Public License as published by    *
+ *   the Free Software Foundation, either version 3 of the License, or       *
+ *   (at your option) any later version.                                     *
+ *                                                                           *
+ *   This program is distributed in the hope that it will be useful,         *
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of          *
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the            *
+ *   GNU General Public License for more details.                            *
+ *                                                                           *
+ *   You should have received a copy of the GNU General Public License       *
+ *   along with this program.  If not, see <http://www.gnu.org/licenses/>.   *
+ *****************************************************************************/
+/*!
+ * \file
+ * \ingroup Common
+ * \ingroup Tests
+ * \brief Testing the Dumux property system
+ */
+
+#include <iostream>
+#include <type_traits>
+
+#include <dune/common/classname.hh>
+#include <dune/common/exceptions.hh>
+
+#include <dumux/common/properties/propertysystem.hh>
+
+namespace Dumux::Properties {
+
+// create some properties like for test_propertysystem
+// in order to make property aliases work, we need to use the macro to define properties
+DUMUX_DEFINE_PROPERTY(Scalar)
+DUMUX_DEFINE_PROPERTY(CoordinateType)
+DUMUX_DEFINE_PROPERTY(UseTpfaFlux)
+
+namespace TTag {
+// create some type tags:
+// the tuple is sorted by precedence, the first one overwriting the following
+struct Base
+{
+    using Scalar = float;
+};
+struct Grid
+{
+    template<class TypeTag>
+    using CoordinateType = GetPropType<TypeTag, Scalar>;
+};
+struct CCTpfaDisc
+{
+    using InheritsFrom = std::tuple<Grid, Base>;
+    using UseTpfaFlux = std::true_type;
+};
+struct BoxDisc
+{
+    using InheritsFrom = std::tuple<Grid, Base>;
+};
+struct OnePModel
+{
+    using InheritsFrom = std::tuple<Base>;
+    using Scalar = std::size_t; // unused because the property is also specialized below
+};
+struct OnePTest
+{
+    using InheritsFrom = std::tuple<OnePModel, BoxDisc>;
+    using Scalar = int;
+};
+
+} // end namespace TTag
+
+// overwrite this one by specialization (takes precedence over alias)
+template<class TypeTag>
+struct Scalar<TypeTag, TTag::OnePModel> { using type = double; };
+
+} // end namespace Dumux::Properties
+
+int main(int argc, char* argv[])
+{
+    using namespace Dumux;
+    using namespace Properties;
+
+    {
+        using Scalar = GetPropType<TTag::Base, Scalar>;
+        if (!std::is_same_v<Scalar, float>)
+            DUNE_THROW(Dune::InvalidStateException, "Property Scalar in TTag::Base should be float but is " << Dune::className<Scalar>());
+    }
+    {
+        using Scalar = GetPropType<TTag::OnePTest, Scalar>;
+        if (!std::is_same_v<Scalar, int>)
+            DUNE_THROW(Dune::InvalidStateException, "Property Scalar in TTag::OnePTest should be int but is " << Dune::className<Scalar>());
+    }
+    {
+        using Scalar = GetPropType<TTag::OnePModel, Scalar>;
+        if (!std::is_same_v<Scalar, double>)
+            DUNE_THROW(Dune::InvalidStateException, "Property Scalar in TTag::OnePModel should be double but is " << Dune::className<Scalar>());
+    }
+    {
+        static_assert(
+            !hasDefinedType<TTag::Base, CoordinateType>(),
+            "Property type should be undefined for TTag::Base"
+        );
+    }
+    {
+        using CoordinateType = GetPropTypeOr<TTag::Base, CoordinateType, double>;
+        static_assert(
+            std::is_same_v<CoordinateType, double>,
+            "Property is expected to default to double"
+        );
+    }
+    {
+        using CoordinateType = GetPropType<TTag::OnePTest, CoordinateType>;
+        if (!std::is_same_v<CoordinateType, int>)
+            DUNE_THROW(Dune::InvalidStateException, "Property CoordinateType in TTag::OnePTest should be int but is " << Dune::className<CoordinateType>());
+    }
+    {
+        using CoordinateType = GetPropType<TTag::CCTpfaDisc, CoordinateType>;
+        if (!std::is_same_v<CoordinateType, float>)
+            DUNE_THROW(Dune::InvalidStateException, "Property CoordinateType in TTag::CCTpfaDisc should be float but is " << Dune::className<CoordinateType>());
+    }
+    {
+        constexpr bool useTpfaFlux = getPropValue<TTag::CCTpfaDisc, UseTpfaFlux>();
+        if (!useTpfaFlux)
+            DUNE_THROW(Dune::InvalidStateException, "Property UseTpfaFlux in TTag::CCTpfaDisc should be true!");
+    }
+
+    std::cout << "All tests passed!" << std::endl;
+    return 0;
+}