fix(server): moved email validation into flags package for reusability

Author: j1n-o9r

internal/cmd/server/service-account/attach/attach.go

@@ -88,7 +88,7 @@ func NewCmd(params *types.CmdParams) *cobra.Command {
 
 func configureFlags(cmd *cobra.Command) {
 	cmd.Flags().VarP(flags.UUIDFlag(), serverIdFlag, "s", "Server ID")
-	cmd.Flags().StringP(serviceAccFlag, "a", "", "Service Account Email")
+	cmd.Flags().VarP(flags.EmailFlag(), serviceAccFlag, "a", "Service Account Email")
 	err := flags.MarkFlagsRequired(cmd, serverIdFlag)
 	cobra.CheckErr(err)
 }

internal/cmd/server/service-account/detach/detach.go

@@ -88,7 +88,7 @@ func NewCmd(params *types.CmdParams) *cobra.Command {
 
 func configureFlags(cmd *cobra.Command) {
 	cmd.Flags().VarP(flags.UUIDFlag(), serverIdFlag, "s", "Server id")
-	cmd.Flags().StringP(serviceAccFlag, "a", "", "Service Account Email")
+	cmd.Flags().VarP(flags.EmailFlag(), serviceAccFlag, "a", "Service Account Email")
 	err := flags.MarkFlagsRequired(cmd, serverIdFlag)
 	cobra.CheckErr(err)
 }

internal/pkg/flags/email.go

@@ -0,0 +1,37 @@
+package flags
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/spf13/pflag"
+)
+
+type emailFlag struct {
+	value string
+}
+
+// Ensure the implementation satisfies the expected interface
+var _ pflag.Value = &emailFlag{}
+
+// EmailFlag returns a flag which must be a valid Email.
+func EmailFlag() *emailFlag {
+	return &emailFlag{}
+}
+
+func (f *emailFlag) String() string {
+	return f.value
+}
+
+func (f *emailFlag) Set(value string) error {
+	isEmail := value != "" && strings.Contains(value, "@")
+	if !isEmail {
+		return fmt.Errorf("invalid email address: %s", value)
+	}
+	f.value = value
+	return nil
+}
+
+func (f *emailFlag) Type() string {
+	return "string"
+}

internal/pkg/flags/email_test.go

@@ -0,0 +1,61 @@
+package flags
+
+import (
+	"testing"
+
+	"github.com/spf13/cobra"
+)
+
+func TestEmailFlag(t *testing.T) {
+	tests := []struct {
+		description string
+		value       string
+		isValid     bool
+	}{
+		{
+			description: "valid",
+			value:       "test@test",
+			isValid:     true,
+		},
+		{
+			description: "empty",
+			value:       "",
+			isValid:     false,
+		},
+		{
+			description: "invalid",
+			value:       "invalid-uuid",
+			isValid:     false,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.description, func(t *testing.T) {
+			flag := EmailFlag()
+			cmd := &cobra.Command{
+				Use: "test",
+				RunE: func(_ *cobra.Command, _ []string) error {
+					return nil
+				},
+			}
+			cmd.Flags().Var(flag, "test-flag", "test")
+
+			err := cmd.Flags().Set("test-flag", tt.value)
+
+			if !tt.isValid && err == nil {
+				t.Fatalf("did not fail on invalid input")
+			}
+			if !tt.isValid {
+				return
+			}
+
+			if err != nil {
+				t.Fatalf("failed on valid input: %v", err)
+			}
+			value := FlagToStringValue(nil, cmd, "test-flag")
+			if value != tt.value {
+				t.Fatalf("flag did not return set value")
+			}
+		})
+	}
+}