Divide tests

calculator.go

@@ -1,13 +1,30 @@
 // Package calculator provides a library for simple calculations in Go.
 package calculator
 
+import "errors"
+
 // Add takes two numbers and returns the result of adding them together.
 func Add(a, b float64) float64 {
-return a + b
+	return a + b
 }
 
 // Subtract takes two numbers and returns the result of subtracting the second
 // from the first.
 func Subtract(a, b float64) float64 {
 	return b - a
 }
+
+// Multiply takes two numbers and returns the result of multplying the second
+// by the first.
+func Multiply(a, b float64) float64 {
+	return b * a
+}
+
+// Divide takes two numbers and returns the result of dividing the second
+// by the first.
+func Divide(a, b float64) (float64, error) {
+	if a != 0 {
+		return b / a, nil
+	}
+	return 0, errors.New("math: Divide by Zero")
+}

calculator_test.go

@@ -2,23 +2,104 @@ package calculator_test
 
 import (
 	"calculator"
+	"fmt"
+	"math/big"
 	"testing"
 )
 
+const (
+	SHLD_SUCCEED = 1 // We expect the test to succeed. If it fails, its an error
+	SHLD_FAIL    = 0 // We expect the test to fail. It it succeeds, its an error
+)
+
+type testCase struct {
+	a           float64
+	b           float64
+	want        float64
+	tcName      string
+	tcExpStatus int
+}
+
 func TestAdd(t *testing.T) {
 	t.Parallel()
-	var want float64 = 4
-	got := calculator.Add(2, 2)
+	tCases := []testCase{
+		{2, 2.030000, 4.030000, "add fractions test 1: exp_succ", SHLD_SUCCEED},
+		{6, 3.99, 9.99, "add fractions test 2: exp_succ", SHLD_SUCCEED},
+		{2, 2.03675, 4.03675, "add fractions test3: exp_succ", SHLD_SUCCEED},
+	}
+	for _, tc := range tCases {
+		got := calculator.Add(tc.a, tc.b)
+		var bgot = big.NewFloat(got)
+		var bwant = big.NewFloat(tc.want)
+		if result := bgot.Cmp(bwant); result != 0 {
+			t.Errorf("Add: Test: %s : want %f, got %f and Cmp gave %d ", tc.tcName, tc.want, got, result)
+		}
+	}
+
+}
+
+func TestSubtract(t *testing.T) {
+	t.Parallel()
+	var want float64 = 2
+	got := calculator.Subtract(2, 4)
+	if want != got {
+		t.Errorf("want %f, got %f", want, got)
+	}
+}
+
+func TestMultiply(t *testing.T) {
+	t.Parallel()
+	var want float64 = 8
+	got := calculator.Multiply(2, 4)
 	if want != got {
 		t.Errorf("want %f, got %f", want, got)
 	}
 }
 
-// func TestSubtract(t *testing.T) {
-// 	t.Parallel()
-// 	var want float64 = 2
-// 	got := calculator.Subtract(4, 2)
-// 	if want != got {
-// 		t.Errorf("want %f, got %f", want, got)
-// 	}
-// }
+func TestDivide(t *testing.T) {
+	t.Parallel()
+	tCases := []testCase{
+		{2.030000, 20, 9.852216, "Divide fractions 1", SHLD_SUCCEED},
+		{2, 0, 0, "Divide fractions 3", SHLD_SUCCEED},
+		{0, 3.99, 0, "Divide by 0", SHLD_FAIL},
+	}
+	cntTestExec, cntfuncErr, cntexpMismatch := 0, 0, 0
+	cntNoOfTests := len(tCases)
+	// If I have deferred it, why is it running here, in the flow. How is it related to tests?
+	defer printDivTestSummary(cntNoOfTests, cntTestExec, cntfuncErr, cntexpMismatch)
+
+	for _, tc := range tCases {
+		funcErr := false
+		expMismatch := false
+		cntTestExec++
+
+		got, err := calculator.Divide(tc.a, tc.b)
+
+		if err != nil {
+			funcErr = true
+			cntfuncErr++
+			t.Fatalf("Test: %s :: (%f / %f) : Divide by Zero", tc.tcName, tc.b, tc.a)
+		} else {
+			if tc.want != got {
+				expMismatch = true
+				cntexpMismatch++
+			}
+		}
+		switch tc.tcExpStatus {
+		case SHLD_FAIL: // We have defined this test case to FAIL. Its err if it doesn't
+			if !(funcErr || expMismatch) {
+				t.Errorf("DivTest: %s :: want %f, got %f ", tc.tcName, tc.want, got)
+			}
+		case SHLD_SUCCEED: // We have defined this test case to SUCCEED. Its err if it doesn't
+			if funcErr || expMismatch {
+				t.Errorf("DivTest: %s :: want %f, got %f ", tc.tcName, tc.want, got)
+			}
+		}
+	}
+	fmt.Printf("SummaryDiv: TotalTests: %d: Executed: %d: Failed: %d: Succeeded: %d\n", cntNoOfTests, cntTestExec, cntfuncErr, cntexpMismatch)
+
+}
+
+func printDivTestSummary(cntNoOfTests, cntTestExec, cntfuncErr, cntexpMismatch int) {
+	fmt.Printf("SummaryDiv: TotalTests: %d: Executed: %d: Failed: %d: Succeeded: %d\n", cntNoOfTests, cntTestExec, cntfuncErr, cntexpMismatch)
+}