add; serializable method that supports debug flag to hide the underlying cause of the error

Author: karthikmuralidharan

debug.go

@@ -0,0 +1,8 @@
+// +build debug
+
+package errors
+
+// Return a serializable error struct that cna omit exposing internal errors as an option in release mode
+func Serializable(err error) *Error {
+	return Unwrap(err)
+}

debug_test.go

@@ -0,0 +1,24 @@
+// +build debug
+
+package errors
+
+import (
+	"testing"
+)
+
+func TestSerializableInDebug(t *testing.T) {
+	cause := New("causal error")
+	const msg = "external error message for the client"
+	err := New(msg, Permission, cause)
+	got := testJSONRoundTrip(Serializable(err)).(*Error)
+	if got.msg != msg {
+		t.Errorf("Serializable(); got msg = %v, want %v", got.msg, msg)
+	}
+	if got.cause == nil || got.cause.Error() != cause.Error() {
+		t.Errorf("Serializable(); got cause.Error() = %v, want %v", got.cause.Error(), cause.Error())
+	}
+	if got.kind != Permission {
+		t.Errorf("Serializable(); got kind = %v, want %v", got.kind, Permission)
+	}
+
+}

release.go

@@ -0,0 +1,10 @@
+// +build !debug
+
+package errors
+
+// Serializable returns a serializable error struct that cna omit exposing internal errors as an option in release mode
+func Serializable(err error) *Error {
+	e := Unwrap(err)
+	e.cause = nil
+	return e
+}

release_test.go

@@ -0,0 +1,23 @@
+// +build !debug
+
+package errors
+
+import (
+	"testing"
+)
+
+func TestSerializableInRelease(t *testing.T) {
+	cause := New("causal error")
+	const msg = "external error message for the client"
+	err := New(msg, Permission, cause)
+	got := testJSONRoundTrip(Serializable(err)).(*Error)
+	if got.msg != msg {
+		t.Errorf("Serializable(); got msg = %v, want %v", got.msg, msg)
+	}
+	if got.cause != nil {
+		t.Errorf("Serializable(); got cause = %v, want %v", got.cause, nil)
+	}
+	if got.kind != Permission {
+		t.Errorf("Serializable(); got kind = %v, want %v", got.kind, Permission)
+	}
+}