From e1e11efd0ea725dd28704bef7d88478586fb9b3b Mon Sep 17 00:00:00 2001
From: David Hill <dhill@mindcry.org>
Date: Wed, 19 Feb 2020 10:22:07 -0500
Subject: [PATCH] dcrutil: use errors api; require go 1.13+

---
 dcrutil/address.go    |  2 +-
 dcrutil/block_test.go | 16 +++++++++-------
 dcrutil/go.mod        |  2 +-
 dcrutil/tx_test.go    |  5 +++--
 4 files changed, 14 insertions(+), 11 deletions(-)

diff --git a/dcrutil/address.go b/dcrutil/address.go
index 64416414..976d2a9f 100644
--- a/dcrutil/address.go
+++ b/dcrutil/address.go
@@ -167,7 +167,7 @@ func DecodeAddress(addr string, net AddressParams) (Address, error) {
 	// Switch on decoded length to determine the type.
 	decoded, netID, err := base58.CheckDecode(addr)
 	if err != nil {
-		if err == base58.ErrChecksum {
+		if errors.Is(err, base58.ErrChecksum) {
 			return nil, ErrChecksumMismatch
 		}
 		return nil, fmt.Errorf("decoded address is of unknown format: %v", err)
diff --git a/dcrutil/block_test.go b/dcrutil/block_test.go
index 2e2c6041..905fa5ef 100644
--- a/dcrutil/block_test.go
+++ b/dcrutil/block_test.go
@@ -1,5 +1,5 @@
 // Copyright (c) 2013-2016 The btcsuite developers
-// Copyright (c) 2015-2019 The Decred developers
+// Copyright (c) 2015-2020 The Decred developers
 // Use of this source code is governed by an ISC
 // license that can be found in the LICENSE file.
 
@@ -7,6 +7,7 @@ package dcrutil
 
 import (
 	"bytes"
+	"errors"
 	"io"
 	"reflect"
 	"testing"
@@ -284,31 +285,32 @@ func TestBlockErrors(t *testing.T) {
 	// Truncate the block byte buffer to force errors.
 	shortBytes := block100000Bytes[:100]
 	_, err = NewBlockFromBytes(shortBytes)
-	if err != io.EOF {
+	if !errors.Is(err, io.EOF) {
 		t.Errorf("NewBlockFromBytes: did not get expected error - "+
 			"got %v, want %v", err, io.EOF)
 	}
 
 	// Ensure TxHash returns expected error on invalid indices.
+	var oErr OutOfRangeError
 	_, err = b.TxHash(-1)
-	if _, ok := err.(OutOfRangeError); !ok {
+	if !errors.As(err, &oErr) {
 		t.Errorf("TxHash: wrong error - got: %v <%T>, "+
 			"want: <%T>", err, err, OutOfRangeError(""))
 	}
 	_, err = b.TxHash(len(Block100000.Transactions) + 1)
-	if _, ok := err.(OutOfRangeError); !ok {
+	if !errors.As(err, &oErr) {
 		t.Errorf("TxHash: wrong error - got: %v <%T>, "+
 			"want: <%T>", err, err, OutOfRangeError(""))
 	}
 
 	// Ensure Tx returns expected error on invalid indices.
 	_, err = b.Tx(-1)
-	if _, ok := err.(OutOfRangeError); !ok {
+	if !errors.As(err, &oErr) {
 		t.Errorf("Tx: wrong error - got: %v <%T>, "+
 			"want: <%T>", err, err, OutOfRangeError(""))
 	}
 	_, err = b.Tx(len(Block100000.Transactions) + 1)
-	if _, ok := err.(OutOfRangeError); !ok {
+	if !errors.As(err, &oErr) {
 		t.Errorf("Tx: wrong error - got: %v <%T>, "+
 			"want: <%T>", err, err, OutOfRangeError(""))
 	}
@@ -316,7 +318,7 @@ func TestBlockErrors(t *testing.T) {
 	// Ensure TxLoc returns expected error with short byte buffer.
 	b.serializedBlock = shortBytes
 	_, _, err = b.TxLoc()
-	if err != io.EOF {
+	if !errors.Is(err, io.EOF) {
 		t.Errorf("TxLoc: did not get expected error - "+
 			"got %v, want %v", err, io.EOF)
 	}
diff --git a/dcrutil/go.mod b/dcrutil/go.mod
index c2e7863f..2b59c1f0 100644
--- a/dcrutil/go.mod
+++ b/dcrutil/go.mod
@@ -1,6 +1,6 @@
 module github.com/decred/dcrd/dcrutil/v3
 
-go 1.11
+go 1.13
 
 require (
 	github.com/davecgh/go-spew v1.1.1
diff --git a/dcrutil/tx_test.go b/dcrutil/tx_test.go
index 53a250f5..713288d3 100644
--- a/dcrutil/tx_test.go
+++ b/dcrutil/tx_test.go
@@ -1,5 +1,5 @@
 // Copyright (c) 2013-2016 The btcsuite developers
-// Copyright (c) 2015-2019 The Decred developers
+// Copyright (c) 2015-2020 The Decred developers
 // Use of this source code is governed by an ISC
 // license that can be found in the LICENSE file.
 
@@ -7,6 +7,7 @@ package dcrutil
 
 import (
 	"bytes"
+	"errors"
 	"io"
 	"reflect"
 	"testing"
@@ -116,7 +117,7 @@ func TestTxErrors(t *testing.T) {
 	// Truncate the transaction byte buffer to force errors.
 	shortBytes := testTxBytes[:4]
 	_, err = NewTxFromBytes(shortBytes)
-	if err != io.EOF {
+	if !errors.Is(err, io.EOF) {
 		t.Errorf("NewTxFromBytes: did not get expected error - "+
 			"got %v, want %v", err, io.EOF)
 	}