feat: Use enum style TLS config (#35)

domains.go

@@ -7,6 +7,13 @@ import (
 	"net/http"
 )
 
+type TlsOption = string
+
+const (
+	Enforced      TlsOption = "enforced"
+	Opportunistic TlsOption = "opportunistic"
+)
+
 type DomainsSvc interface {
 	CreateWithContext(ctx context.Context, params *CreateDomainRequest) (CreateDomainResponse, error)
 	Create(params *CreateDomainRequest) (CreateDomainResponse, error)
@@ -46,9 +53,9 @@ type ListDomainsResponse struct {
 }
 
 type UpdateDomainRequest struct {
-	OpenTracking  bool   `json:"open_tracking,omitempty"`
-	ClickTracking bool   `json:"click_tracking,omitempty"`
-	Tls           string `json:"tls,omitempty"`
+	OpenTracking  bool      `json:"open_tracking,omitempty"`
+	ClickTracking bool      `json:"click_tracking,omitempty"`
+	Tls           TlsOption `json:"tls,omitempty"`
 }
 
 type Domain struct {

domains_test.go

@@ -229,7 +229,7 @@ func TestUpdateDomain(t *testing.T) {
 
 	params := &UpdateDomainRequest{
 		OpenTracking: true,
-		Tls:          "opportunistic",
+		Tls:          Opportunistic,
 	}
 	updated, err := client.Domains.Update("d91cd9bd-1176-453e-8fc1-35364d380206", params)
 	if err != nil {

examples/domains.go

@@ -8,7 +8,7 @@ import (
 	"github.com/resend/resend-go/v2"
 )
 
-func domainsExample() {
+func domainExample() {
 	ctx := context.TODO()
 	apiKey := os.Getenv("RESEND_API_KEY")
 
@@ -40,7 +40,7 @@ func domainsExample() {
 	updateDomainParams := &resend.UpdateDomainRequest{
 		OpenTracking:  true,
 		ClickTracking: true,
-		Tls:           "opportunistic",
+		Tls:           resend.Enforced,
 	}
 
 	updated, err := client.Domains.UpdateWithContext(ctx, domain.Id, updateDomainParams)