From 8effa0cd3eafec0ba7bc4fa8dd7c2a610509b86e Mon Sep 17 00:00:00 2001
From: Niels de Vos <ndevos@redhat.com>
Date: Tue, 30 Jun 2020 08:43:24 +0200
Subject: [PATCH] util: add Unwrap() to error types

See-also: https://github.com/golang/go/wiki/ErrorValueFAQ#i-have-a-type-that-implements-error-and-holds-a-nested-error-how-should-i-adapt-it-to-the-new-features
Signed-off-by: Niels de Vos <ndevos@redhat.com>
---
 internal/util/errors.go | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/internal/util/errors.go b/internal/util/errors.go
index 45fd20b1f..883c20997 100644
--- a/internal/util/errors.go
+++ b/internal/util/errors.go
@@ -32,6 +32,11 @@ func (e ErrKeyNotFound) Error() string {
 	return e.err.Error()
 }
 
+// Unwrap returns the encapsulated error.
+func (e ErrKeyNotFound) Unwrap() error {
+	return e.err
+}
+
 // ErrObjectExists is returned when named omap is already present in rados
 type ErrObjectExists struct {
 	objectName string
@@ -43,6 +48,11 @@ func (e ErrObjectExists) Error() string {
 	return e.err.Error()
 }
 
+// Unwrap returns the encapsulated error.
+func (e ErrObjectExists) Unwrap() error {
+	return e.err
+}
+
 // ErrObjectNotFound is returned when named omap is not found in rados
 type ErrObjectNotFound struct {
 	oMapName string
@@ -54,6 +64,11 @@ func (e ErrObjectNotFound) Error() string {
 	return e.err.Error()
 }
 
+// Unwrap returns the encapsulated error.
+func (e ErrObjectNotFound) Unwrap() error {
+	return e.err
+}
+
 // ErrSnapNameConflict is generated when a requested CSI snap name already exists on RBD but with
 // different properties, and hence is in conflict with the passed in CSI volume name
 type ErrSnapNameConflict struct {
@@ -66,6 +81,11 @@ func (e ErrSnapNameConflict) Error() string {
 	return e.err.Error()
 }
 
+// Unwrap returns the encapsulated error.
+func (e ErrSnapNameConflict) Unwrap() error {
+	return e.err
+}
+
 // NewErrSnapNameConflict returns a ErrSnapNameConflict error when CSI snap name already exists.
 func NewErrSnapNameConflict(name string, err error) ErrSnapNameConflict {
 	return ErrSnapNameConflict{name, err}
@@ -82,6 +102,11 @@ func (e ErrPoolNotFound) Error() string {
 	return e.Err.Error()
 }
 
+// Unwrap returns the encapsulated error.
+func (e ErrPoolNotFound) Unwrap() error {
+	return e.Err
+}
+
 // NewErrPoolNotFound returns a new ErrPoolNotFound error.
 func NewErrPoolNotFound(pool string, err error) ErrPoolNotFound {
 	return ErrPoolNotFound{pool, err}