Add file for tesing income service

src/test/java/com/faf223/expensetrackerfaf/service/IncomeServiceTest.java

@@ -0,0 +1,26 @@
+package com.faf223.expensetrackerfaf.service;
+
+import com.faf223.expensetrackerfaf.repository.IncomeRepository;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.InjectMocks;
+import org.mockito.Mock;
+import org.mockito.junit.jupiter.MockitoExtension;
+
+@ExtendWith(MockitoExtension.class)
+public class IncomeServiceTest {
+
+    @Mock
+    private IncomeRepository incomeRepository;
+
+    @InjectMocks
+    private IncomeService incomeService;
+
+    @Test
+    public void IncomeService_CreateIncome_ReturnsIncome() {
+
+
+
+    }
+
+}