Don't bind to reference in order not to overwrite entity instance storage in case of IfcPropertySetDefinitionSet

src/ifcparse/tests/CMakeLists.txt

@@ -3,9 +3,15 @@
 add_executable(test_ifcopenshell_parse
     test_ifcopenshell_parse.cpp
 )
-target_link_libraries(test_ifcopenshell_parse PRIVATE Catch2::Catch2WithMain)
+target_compile_definitions(test_ifcopenshell_parse PRIVATE
+    IFCOPENSHELL_TEST_FIXTURES="${CMAKE_CURRENT_SOURCE_DIR}/../../ifcopenshell-python/test/fixtures"
+)
+target_link_libraries(test_ifcopenshell_parse PRIVATE Catch2::Catch2WithMain IfcParse)
+add_dependencies(test_ifcopenshell_parse parse_schema_ifc4)
 catch_discover_tests(test_ifcopenshell_parse
     DL_PATHS
         $<TARGET_FILE_DIR:Catch2::Catch2>
         $<TARGET_FILE_DIR:Catch2::Catch2WithMain>
+        $<TARGET_FILE_DIR:IfcParse>
+        $<TARGET_FILE_DIR:plugin>
 )

src/ifcparse/tests/test_ifcopenshell_parse.cpp

@@ -1,7 +1,27 @@
 // This file was generated with the assistance of an AI coding tool.
 
 #include <catch2/catch_test_macros.hpp>
+#include <ifcparse/file.h>
+#include <string>
+#include <vector>
 
-TEST_CASE("IfcParse C++ test scaffold is registered", "[ifcparse]") {
-    REQUIRE(true);
+TEST_CASE("IfcPropertySetDefinitionSet references are resolved without replacing their owner", "[ifcparse]") {
+    const std::string fixture = std::string(IFCOPENSHELL_TEST_FIXTURES) + "/ColumnPSetsOfSets.ifc";
+    ifcopenshell::file file(fixture);
+
+    REQUIRE(file.good());
+
+    const auto relationship = file.instance_by_id(139);
+    REQUIRE(relationship);
+    CHECK(relationship.id() == 139);
+    CHECK(relationship.declaration().name() == "IfcRelDefinesByProperties");
+
+    const express::base definition_set = relationship.get_attribute_value(5);
+    REQUIRE(definition_set);
+    CHECK(definition_set.declaration().name() == "IfcPropertySetDefinitionSet");
+
+    const std::vector<express::base> definitions = definition_set.get_attribute_value(0);
+    REQUIRE(definitions.size() == 2);
+    CHECK(definitions[0].id() == 136);
+    CHECK(definitions[1].id() == 138);
 }