make endpoints pointers to enable/disable them

pkg/op/endpoint.go

@@ -1,32 +1,46 @@
 package op
 
-import "strings"
+import (
+	"errors"
+	"strings"
+)
 
 type Endpoint struct {
 	path string
 	url  string
 }
 
-func NewEndpoint(path string) Endpoint {
-	return Endpoint{path: path}
+func NewEndpoint(path string) *Endpoint {
+	return &Endpoint{path: path}
 }
 
-func NewEndpointWithURL(path, url string) Endpoint {
-	return Endpoint{path: path, url: url}
+func NewEndpointWithURL(path, url string) *Endpoint {
+	return &Endpoint{path: path, url: url}
 }
 
-func (e Endpoint) Relative() string {
+func (e *Endpoint) Relative() string {
+	if e == nil {
+		return ""
+	}
 	return relativeEndpoint(e.path)
 }
 
-func (e Endpoint) Absolute(host string) string {
+func (e *Endpoint) Absolute(host string) string {
+	if e == nil {
+		return ""
+	}
 	if e.url != "" {
 		return e.url
 	}
 	return absoluteEndpoint(host, e.path)
 }
 
-func (e Endpoint) Validate() error {
+var ErrNilEndpoint = errors.New("nil endpoint")
+
+func (e *Endpoint) Validate() error {
+	if e == nil {
+		return ErrNilEndpoint
+	}
 	return nil // TODO:
 }