From 09e55f21458f9929edce6d41d976dc394f730550 Mon Sep 17 00:00:00 2001
From: Daniel Nephin <dnephin@gmail.com>
Date: Sun, 12 Jul 2020 22:27:32 -0400
Subject: [PATCH 1/2] Add Unwrap for compat with go1.13 errors

---
 errwrap.go      |  4 ++++
 errwrap_test.go | 10 ++++++++++
 2 files changed, 14 insertions(+)

diff --git a/errwrap.go b/errwrap.go
index a733bef..325f278 100644
--- a/errwrap.go
+++ b/errwrap.go
@@ -167,3 +167,7 @@ func (w *wrappedError) Error() string {
 func (w *wrappedError) WrappedErrors() []error {
 	return []error{w.Outer, w.Inner}
 }
+
+func (w *wrappedError) Unwrap() error {
+	return w.Inner
+}
\ No newline at end of file
diff --git a/errwrap_test.go b/errwrap_test.go
index 5ae5f8e..60d37d3 100644
--- a/errwrap_test.go
+++ b/errwrap_test.go
@@ -1,6 +1,7 @@
 package errwrap
 
 import (
+	"errors"
 	"fmt"
 	"testing"
 )
@@ -92,3 +93,12 @@ func TestGetAllType(t *testing.T) {
 		}
 	}
 }
+
+func TestWrappedError_IsCompatibleWithErrorsUnwrap(t *testing.T) {
+	inner := errors.New("inner error")
+	err := Wrap(errors.New("outer"), inner)
+	actual := errors.Unwrap(err)
+	if actual != inner {
+		t.Fatal("wrappedError did not unwrap to inner")
+	}
+}
\ No newline at end of file

From 96a78fc01475f1ab9853c716f182a5107af3fc91 Mon Sep 17 00:00:00 2001
From: Daniel Nephin <dnephin@gmail.com>
Date: Sun, 12 Jul 2020 23:23:39 -0400
Subject: [PATCH 2/2] Unwrap in Walk for compat with go1.13 errors

---
 errwrap.go      |  7 ++++++-
 errwrap_test.go | 17 ++++++++++++++++-
 2 files changed, 22 insertions(+), 2 deletions(-)

diff --git a/errwrap.go b/errwrap.go
index 325f278..44e368e 100644
--- a/errwrap.go
+++ b/errwrap.go
@@ -44,6 +44,8 @@ func Wrap(outer, inner error) error {
 //
 // format is the format of the error message. The string '{{err}}' will
 // be replaced with the original error message.
+//
+// Deprecated: Use fmt.Errorf()
 func Wrapf(format string, err error) error {
 	outerMsg := "<nil>"
 	if err != nil {
@@ -148,6 +150,9 @@ func Walk(err error, cb WalkFunc) {
 		for _, err := range e.WrappedErrors() {
 			Walk(err, cb)
 		}
+	case interface{ Unwrap() error }:
+		cb(err)
+		Walk(e.Unwrap(), cb)
 	default:
 		cb(err)
 	}
@@ -170,4 +175,4 @@ func (w *wrappedError) WrappedErrors() []error {
 
 func (w *wrappedError) Unwrap() error {
 	return w.Inner
-}
\ No newline at end of file
+}
diff --git a/errwrap_test.go b/errwrap_test.go
index 60d37d3..8c16a56 100644
--- a/errwrap_test.go
+++ b/errwrap_test.go
@@ -42,6 +42,16 @@ func TestGetAll(t *testing.T) {
 			"foo",
 			1,
 		},
+		{
+			fmt.Errorf("foo: %w", fmt.Errorf("bar")),
+			"foo: bar",
+			1,
+		},
+		{
+			fmt.Errorf("foo: %w", fmt.Errorf("bar")),
+			"bar",
+			1,
+		},
 	}
 
 	for i, tc := range cases {
@@ -84,6 +94,11 @@ func TestGetAllType(t *testing.T) {
 			Wrapf("", nil),
 			0,
 		},
+		{
+			fmt.Errorf("one: %w", fmt.Errorf("two: %w", fmt.Errorf("three"))),
+			fmt.Errorf("%w", errors.New("")),
+			2,
+		},
 	}
 
 	for i, tc := range cases {
@@ -101,4 +116,4 @@ func TestWrappedError_IsCompatibleWithErrorsUnwrap(t *testing.T) {
 	if actual != inner {
 		t.Fatal("wrappedError did not unwrap to inner")
 	}
-}
\ No newline at end of file
+}