Merge pull request anz-bank#412 from mohitnag/lab5

Lab5 - Stringer

05_stringer/mohitnag/main.go

@@ -0,0 +1,20 @@
+package main
+
+import (
+	"fmt"
+	"io"
+	"os"
+)
+
+// IPAddr is a type implementing fmt.Stringer
+type IPAddr [4]byte
+
+var out io.Writer = os.Stdout
+
+func (ip IPAddr) String() string {
+	return fmt.Sprintf("%d.%d.%d.%d", ip[0], ip[1], ip[2], ip[3])
+}
+
+func main() {
+	fmt.Fprintln(out, IPAddr{127, 0, 0, 1})
+}

05_stringer/mohitnag/main_test.go

@@ -0,0 +1,38 @@
+package main
+
+import (
+	"bytes"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestIpaddr(t *testing.T) {
+	testData := []struct {
+		Scenario string
+		input    IPAddr
+		expected string
+	}{
+		{"Happy Day", [4]byte{127, 0, 0, 1}, "127.0.0.1"},
+		{"empty", [4]byte{}, "0.0.0.0"},
+		{"one byte non zero", [4]byte{0, 0, 0, 10}, "0.0.0.10"},
+		{"boundary validation", [4]byte{255, 255, 255, 255}, "255.255.255.255"},
+		{"only one byte", [4]byte{10}, "10.0.0.0"},
+	}
+	for _, td := range testData {
+		td := td
+		t.Run(td.Scenario, func(t *testing.T) {
+			actual := td.input.String()
+			assert.Equal(t, td.expected, actual)
+		})
+	}
+}
+func TestMain(t *testing.T) {
+	assert := assert.New(t)
+	var buf bytes.Buffer
+	out = &buf
+	main()
+	expected := "127.0.0.1\n"
+	actual := buf.String()
+	assert.Equal(expected, actual)
+}