Added additional calculation possibilities; Added tests

Author: savannah-ryan

calc/caclulator_test.go

@@ -7,6 +7,18 @@ func TestAddition(t *testing.T) {
 	assertEqual(t, 4, Addition{}.Calculate(2, 2))
 }
 
+func TestSubtraction(t *testing.T) {
+	assertEqual(t, 3, Subtraction{}.Calculate(5, 2))
+	assertEqual(t, 0, Subtraction{}.Calculate(2, 2))
+}
+func TestMultiplication(t *testing.T) {
+	assertEqual(t, 4, Multiplication{}.Calculate(2, 2))
+	assertEqual(t, 3, Multiplication{}.Calculate(1, 3))
+}
+func TestDivision(t *testing.T) {
+	assertEqual(t, 1, Division{}.Calculate(2, 2))
+}
+
 func assertEqual(t *testing.T, expected, actual any) {
 	if actual != expected {
 		t.Errorf("Expected: %v -> Actual: %v", expected, actual)

calc/calculator.go

@@ -1,11 +1,17 @@
 package calc
 
-type Calculator interface{ Calculate(a, b int) int }
+func (Addition) Calculate(a, b int) int {
+	return a + b
+}
 
-type Addition struct {
-	calculator Calculator
+func (Subtraction) Calculate(a, b int) int {
+	return a - b
 }
 
-func (Addition) Calculate(a, b int) int {
-	return a + b
+func (Multiplication) Calculate(a, b int) int {
+	return a * b
+}
+
+func (Division) Calculate(a, b int) int {
+	return a / b
 }

calc/types.go

@@ -0,0 +1,16 @@
+package calc
+
+type Calculator interface{ Calculate(a, b int) int }
+
+type Addition struct {
+	calculator Calculator
+}
+type Subtraction struct {
+	calculator Calculator
+}
+type Multiplication struct {
+	calculator Calculator
+}
+type Division struct {
+	calculator Calculator
+}