Adding a hostname flag option for use with gh api

utils/utils.go

@@ -1,6 +1,7 @@
 package utils
 
 import (
+	"errors"
 	"fmt"
 	"io"
 	"net/url"
@@ -28,6 +29,21 @@ func OpenInBrowser(url string) error {
 	return err
 }
 
+func HostnameValidator(v interface{}) error {
+	hostname, valid := v.(string)
+	if !valid {
+		return errors.New("hostname is not a string")
+	}
+
+	if len(strings.TrimSpace(hostname)) < 1 {
+		return errors.New("a value is required")
+	}
+	if strings.ContainsRune(hostname, '/') || strings.ContainsRune(hostname, ':') {
+		return errors.New("invalid hostname")
+	}
+	return nil
+}
+
 func Pluralize(num int, thing string) string {
 	if num == 1 {
 		return fmt.Sprintf("%d %s", num, thing)

utils/utils_test.go

@@ -3,6 +3,8 @@ package utils
 import (
 	"testing"
 	"time"
+
+	"github.com/stretchr/testify/assert"
 )
 
 func TestFuzzyAgo(t *testing.T) {
@@ -36,3 +38,48 @@ func TestFuzzyAgo(t *testing.T) {
 		}
 	}
 }
+
+func TestHostnameValidator(t *testing.T) {
+	tests := []struct {
+		name     string
+		input    interface{}
+		wantsErr bool
+	}{
+		{
+			name:     "valid hostname",
+			input:    "internal.instance",
+			wantsErr: false,
+		},
+		{
+			name:     "hostname with slashes",
+			input:    "//internal.instance",
+			wantsErr: true,
+		},
+		{
+			name:     "empty hostname",
+			input:    "   ",
+			wantsErr: true,
+		},
+		{
+			name:     "hostname with colon",
+			input:    "internal.instance:2205",
+			wantsErr: true,
+		},
+		{
+			name:     "non-string hostname",
+			input:    62,
+			wantsErr: true,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			err := HostnameValidator(tt.input)
+			if tt.wantsErr {
+				assert.Error(t, err)
+				return
+			}
+			assert.Equal(t, nil, err)
+		})
+	}
+}