refactoring hemocube fragment and add tests

app/src/test/java/com/example/hpostesting/MathApplicationTest.kt

@@ -0,0 +1,31 @@
+package com.example.hpostesting
+
+import io.mockk.every
+import io.mockk.mockk
+import io.mockk.verify
+import junit.framework.TestCase.assertEquals
+import org.junit.Test
+
+class MathApplicationTest {
+
+    @Test
+    fun testAddNumbers() {
+        // Create a mock of the Calculator class using Mockito-Kotlin
+        val calculatorMock = mockk<Calculator>()
+
+        // Define the behavior of the add method on the mock
+        every { calculatorMock.add(2, 3) } returns 5
+
+        // Create an instance of MathApplication with the mock Calculator
+        val mathApplication = MathApplication(calculatorMock)
+
+        // Perform the test using the MathApplication
+        val result = mathApplication.addNumbers(2, 3)
+
+        // Verify that the add method of the mock was called with the correct parameters
+        verify { calculatorMock.add(2, 3) }
+
+        // Verify the result of the test
+        assertEquals(5, result)
+    }
+}