Enum classes are instantiated correctly if some methods are overriden

Author: EgorkaKulikov

utbot-framework/src/main/kotlin/org/utbot/framework/codegen/tree/CgStatementConstructor.kt

@@ -63,6 +63,8 @@ import org.utbot.framework.plugin.api.util.fieldClassId
 import org.utbot.framework.plugin.api.util.isPrimitive
 import org.utbot.framework.plugin.api.util.methodClassId
 import org.utbot.framework.plugin.api.util.denotableType
+import org.utbot.framework.plugin.api.util.id
+import org.utbot.framework.plugin.api.util.isEnum
 import org.utbot.framework.plugin.api.util.supertypeOfAnonymousClass
 import java.lang.reflect.Constructor
 import java.lang.reflect.Method
@@ -500,11 +502,13 @@ internal class CgStatementConstructorImpl(context: CgContext) :
     }
 
     private fun guardEnumConstantAccess(access: CgEnumConstantAccess): ExpressionWithType {
-        val (enumClass, constant) = access
+        val (enumAccessClass, constant) = access
 
-        return if (enumClass.isAccessibleFrom(testClassPackageName)) {
-            ExpressionWithType(enumClass, access)
+        return if (enumAccessClass.isAccessibleFrom(testClassPackageName)) {
+            ExpressionWithType(enumAccessClass, access)
         } else {
+            val enumClass: ClassId =
+                if (enumAccessClass.isEnum) enumAccessClass else enumAccessClass.superclass!!.id
             val enumClassVariable = newVar(classCgClassId) {
                 classClassId[forName](enumClass.name)
             }

utbot-framework/src/main/kotlin/org/utbot/framework/codegen/tree/CgVariableConstructor.kt

@@ -58,6 +58,7 @@ import org.utbot.framework.plugin.api.util.findFieldByIdOrNull
 import org.utbot.framework.plugin.api.util.id
 import org.utbot.framework.plugin.api.util.intClassId
 import org.utbot.framework.plugin.api.util.isArray
+import org.utbot.framework.plugin.api.util.isEnum
 import org.utbot.framework.plugin.api.util.isPrimitiveWrapperOrString
 import org.utbot.framework.plugin.api.util.isStatic
 import org.utbot.framework.plugin.api.util.stringClassId
@@ -445,8 +446,15 @@ open class CgVariableConstructor(val context: CgContext) :
     }
 
     private fun constructEnumConstant(model: UtEnumConstantModel, baseName: String?): CgVariable {
-        return newVar(model.classId, baseName) {
-            CgEnumConstantAccess(model.classId, model.value.name)
+        val classId = model.classId
+
+        require(classId.isEnum ||
+                classId.isAnonymous && classId.superclass?.isEnum == true) {
+            "Enum constant model $model should be a enum or an anonymous class that overrides enum methods"
+        }
+
+        return newVar(classId, baseName) {
+            CgEnumConstantAccess(classId, model.value.name)
         }
     }