creating units tests for get country by name

src/test/java/org/airpenthouse/GoTel/entities/countries/TestCountriesEntity.java

@@ -0,0 +1,88 @@
+package org.airpenthouse.GoTel.entities.countries;
+
+import org.airpenthouse.GoTel.entities.country.CountriesEntity;
+import org.junit.jupiter.api.*;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.InjectMocks;
+import org.mockito.Mock;
+import org.mockito.junit.jupiter.MockitoExtension;
+
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+import java.sql.PreparedStatement;
+import java.util.List;
+import java.util.Set;
+
+import static org.airpenthouse.GoTel.util.PropertiesUtilManager.*;
+import static org.junit.jupiter.api.Assertions.*;
+
+@ExtendWith(MockitoExtension.class)
+public class TestCountriesEntity {
+
+    @Mock
+    private PreparedStatement ps;
+    @InjectMocks
+    private CountriesEntity countriesEntity;
+
+    @BeforeAll
+    public static void init() {
+
+    }
+
+    @AfterEach
+    public void initAfterEach() {
+        setProperties("countryName", "");
+    }
+
+    @AfterAll
+    public static void clean(){
+
+    }
+
+    @Test
+    public void TestPrivateMethod_GetCountryByName() throws NoSuchMethodException, InvocationTargetException, IllegalAccessException {
+        setProperties("countryName", "South Africa");
+        var list = reflectPrivateMethod("getCountryByName");
+        assertTrue(list.get(0).getCountryName().equals(getPropertiesValue("countryName")));
+    }
+
+    /*
+    Here testing when country is not  provide
+     */
+    @Test
+    public void TestPrivateMethod_GetCountryByNameEmptyCountryName() throws NoSuchMethodException, InvocationTargetException, IllegalAccessException {
+        setProperties("countryName", "");
+        var list = reflectPrivateMethod("getCountryByName");
+        assertTrue(list.isEmpty());
+    }
+
+    /*
+        Test when server is down throw NullPointer
+     */
+
+    @Test
+    public void TestPrivateMethod_GetCountryByNameWhenServerIsDown() throws NoSuchMethodException, InvocationTargetException, IllegalAccessException {
+        setProperties("countryName", "");
+        assertThrows(NullPointerException.class,()-> reflectPrivateMethod("getCountryByName"));
+    }
+
+    /*
+   Here testing when country is not  correct
+    */
+    @Test
+    public void TestPrivateMethod_GetCountryByNameEmptyIsInvalid() throws NoSuchMethodException, InvocationTargetException, IllegalAccessException {
+        setProperties("countryName", "South African Flag");
+        var list = reflectPrivateMethod("getCountryByName");
+        assertTrue(list.isEmpty());
+    }
+
+    private List<CountriesEntity> reflectPrivateMethod(String methodName) throws InvocationTargetException, IllegalAccessException, NoSuchMethodException {
+        Method reflectedMethodName = CountriesEntity.class.getDeclaredMethod(methodName);
+        reflectedMethodName.setAccessible(true);
+
+        var set = (Set<CountriesEntity>) reflectedMethodName.invoke(countriesEntity);
+
+        return set.stream().toList();
+    }
+
+}