SONARJAVA-5624 Fix coverage of JTypeSymbol new code (#5194)

Author: alban-auzeill

java-frontend/src/test/java/org/sonar/java/model/JTypeSymbolTest.java

@@ -22,6 +22,7 @@
 import org.sonar.java.model.declaration.ClassTreeImpl;
 import org.sonar.java.model.declaration.MethodTreeImpl;
 import org.sonar.java.model.declaration.VariableTreeImpl;
+import org.sonar.plugins.java.api.semantic.Type;
 
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.junit.jupiter.api.Assertions.assertAll;
@@ -60,6 +61,17 @@ void superClass() {
     );
   }
 
+  @Test
+  void testSuperClassWhenSemanticCanNotResolveObjectType() {
+    var cu = test("interface I{}");
+    var i = (ClassTreeImpl) cu.types().get(0);
+
+    JSema sematicThatCanNotResolveObjectType = spy(cu.sema);
+    when(sematicThatCanNotResolveObjectType.resolveType("java.lang.Object")).thenReturn(null);
+    var typeSymbol = new JTypeSymbol(sematicThatCanNotResolveObjectType, i.typeBinding);
+    assertThat(typeSymbol.superClass()).isSameAs(Type.UNKNOWN);
+  }
+
   @Test
   void interfaces() {
     JavaTree.CompilationUnitTreeImpl cu = test("interface I { } class C implements I { }");