Fixed nested classes generation

Author: DaniilStepanov

utbot-framework/src/main/kotlin/org/utbot/framework/codegen/domain/context/CgContext.kt

@@ -552,7 +552,7 @@ data class CgContext(
     }
 
     private fun createClassIdForNestedClass(testClassModel: TestClassModel): ClassId {
-        val simpleName = "${testClassModel.classUnderTest.simpleName}Test"
+        val simpleName = "${testClassModel.classUnderTest.simpleName}Tests"
         return BuiltinClassId(
             canonicalName = currentTestClass.canonicalName + "." + simpleName,
             simpleName = simpleName,

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

@@ -92,32 +92,41 @@ open class CgTestClassConstructor(val context: CgContext) :
                         )
                     )
                 }
-
-                for (testSet in testClassModel.methodTestSets) {
-                    updateCurrentExecutable(testSet.executableId)
-                    val currentMethodUnderTestRegions = constructTestSet(testSet) ?: continue
-                    val executableUnderTestCluster = CgMethodsCluster(
-                        "Test suites for executable $currentExecutable",
-                        currentMethodUnderTestRegions
+                if (testClassModel.nestedClasses.isNotEmpty()) {
+                    val newTestClassModel = TestClassModel(testClassModel.classUnderTest, testClassModel.methodTestSets, emptyList())
+                    nestedClassRegions += CgRealNestedClassesRegion(
+                        "Tests for ${classUnderTest.simpleName}",
+                        listOf(
+                            withNestedClassScope(newTestClassModel) { constructTestClass(newTestClassModel) }
+                        )
                     )
-                    methodRegions += executableUnderTestCluster
-                }
-
-                val currentTestClassDataProviderMethods = currentTestClassContext.cgDataProviderMethods
-                if (currentTestClassDataProviderMethods.isNotEmpty()) {
-                    staticDeclarationRegions +=
-                        CgStaticsRegion(
-                            "Data provider methods for parametrized tests",
-                            currentTestClassDataProviderMethods,
+                } else {
+                    for (testSet in testClassModel.methodTestSets) {
+                        updateCurrentExecutable(testSet.executableId)
+                        val currentMethodUnderTestRegions = constructTestSet(testSet) ?: continue
+                        val executableUnderTestCluster = CgMethodsCluster(
+                            "Test suites for executable $currentExecutable",
+                            currentMethodUnderTestRegions
                         )
-                }
+                        methodRegions += executableUnderTestCluster
+                    }
+
+                    val currentTestClassDataProviderMethods = currentTestClassContext.cgDataProviderMethods
+                    if (currentTestClassDataProviderMethods.isNotEmpty()) {
+                        staticDeclarationRegions +=
+                            CgStaticsRegion(
+                                "Data provider methods for parametrized tests",
+                                currentTestClassDataProviderMethods,
+                            )
+                    }
 
-                if (currentTestClass == outerMostTestClass) {
-                    val utilEntities = collectUtilEntities()
-                    // If utilMethodProvider is TestClassUtilMethodProvider, then util entities should be declared
-                    // in the test class. Otherwise, util entities will be located elsewhere (e.g. another class).
-                    if (utilMethodProvider is TestClassUtilMethodProvider && utilEntities.isNotEmpty()) {
-                        staticDeclarationRegions += CgStaticsRegion("Util methods", utilEntities)
+                    if (currentTestClass == outerMostTestClass) {
+                        val utilEntities = collectUtilEntities()
+                        // If utilMethodProvider is TestClassUtilMethodProvider, then util entities should be declared
+                        // in the test class. Otherwise, util entities will be located elsewhere (e.g. another class).
+                        if (utilMethodProvider is TestClassUtilMethodProvider && utilEntities.isNotEmpty()) {
+                            staticDeclarationRegions += CgStaticsRegion("Util methods", utilEntities)
+                        }
                     }
                 }
             }