refactor(errors): use errors.is to account wrapped errors

cmd/maddy-shadow-helper/main.go

@@ -20,6 +20,7 @@ package main
 
 import (
 	"bufio"
+	"errors"
 	"fmt"
 	"os"
 
@@ -43,7 +44,7 @@ func main() {
 
 	ent, err := shadow.Lookup(username)
 	if err != nil {
-		if err == shadow.ErrNoSuchUser {
+		if errors.Is(err, shadow.ErrNoSuchUser) {
 			os.Exit(1)
 		}
 		fmt.Fprintln(os.Stderr, err)
@@ -61,7 +62,7 @@ func main() {
 	}
 
 	if err := ent.VerifyPassword(password); err != nil {
-		if err == shadow.ErrWrongPassword {
+		if errors.Is(err, shadow.ErrWrongPassword) {
 			os.Exit(1)
 		}
 		fmt.Fprintln(os.Stderr, err)

framework/future/future_test.go

@@ -69,7 +69,7 @@ func TestFuture_WaitCtx(t *testing.T) {
 	ctx, cancel := context.WithTimeout(context.Background(), 500*time.Millisecond)
 	defer cancel()
 	_, err := f.GetContext(ctx)
-	if err != context.DeadlineExceeded {
+	if !errors.Is(err, context.DeadlineExceeded) {
 		t.Fatal("context is not cancelled")
 	}
 }

internal/auth/shadow/module.go

@@ -91,7 +91,9 @@ func (a *Auth) Lookup(username string) (string, bool, error) {
 
 	ent, err := Lookup(username)
 	if err != nil {
-		return "", false, nil
+		if errors.Is(err, ErrNoSuchUser) {
+			return "", false, nil
+		}
 	}
 
 	if !ent.IsAccountValid() {
@@ -120,7 +122,7 @@ func (a *Auth) AuthPlain(username, password string) error {
 	}
 
 	if err := ent.VerifyPassword(password); err != nil {
-		if err == ErrWrongPassword {
+		if errors.Is(err, ErrWrongPassword) {
 			return module.ErrUnknownCredentials
 		}
 		return err

internal/auth/shadow/verify.go

@@ -67,7 +67,7 @@ func (e *Entry) VerifyPassword(pass string) (err error) {
 	}()
 
 	if err := crypt.NewFromHash(e.Pass).Verify(e.Pass, []byte(pass)); err != nil {
-		if err == crypt.ErrKeyMismatch {
+		if errors.Is(err, crypt.ErrKeyMismatch) {
 			return ErrWrongPassword
 		}
 		return err

internal/check/dnsbl/dnsbl_test.go

@@ -20,8 +20,8 @@ package dnsbl
 
 import (
 	"context"
+	"errors"
 	"net"
-	"reflect"
 	"testing"
 
 	"github.com/foxcpp/go-mockdns"
@@ -35,7 +35,7 @@ func TestCheckList(t *testing.T) {
 			log:      testutils.Logger(t, "dnsbl"),
 		}
 		err := mod.checkList(context.Background(), cfg, ip, ehlo, mailFrom)
-		if !reflect.DeepEqual(err, expectedErr) {
+		if !errors.Is(err, expectedErr) {
 			t.Errorf("expected err to be '%#v', got '%#v'", expectedErr, err)
 		}
 	}

internal/endpoint/openmetrics/om.go

@@ -19,6 +19,7 @@ along with this program.  If not, see <https://www.gnu.org/licenses/>.
 package openmetrics
 
 import (
+	"errors"
 	"fmt"
 	"net"
 	"net/http"
@@ -76,7 +77,7 @@ func (e *Endpoint) Init(cfg *config.Map) error {
 		go func() {
 			e.logger.Println("listening on", endp.String())
 			err := e.serv.Serve(l)
-			if err != nil && err != http.ErrServerClosed {
+			if err != nil && !errors.Is(err, http.ErrServerClosed) {
 				e.logger.Error("serve failed", err, "endpoint", a)
 			}
 		}()

internal/endpoint/smtp/session.go

@@ -236,7 +236,7 @@ func (s *Session) Mail(from string, opts smtp.MailOptions) error {
 		// Will initialize s.msgCtx.
 		msgID, err := s.startDelivery(s.sessionCtx, from, opts)
 		if err != nil {
-			if err != context.DeadlineExceeded {
+			if !errors.Is(err, context.DeadlineExceeded) {
 				s.log.Error("MAIL FROM error", err, "msg_id", msgID)
 			}
 			return s.endp.wrapErr(msgID, !opts.UTF8, "MAIL", err)
@@ -300,7 +300,7 @@ func (s *Session) Rcpt(to string) error {
 		// It will initialize s.msgCtx.
 		msgID, err := s.startDelivery(s.sessionCtx, s.mailFrom, s.opts)
 		if err != nil {
-			if err != context.DeadlineExceeded {
+			if !errors.Is(err, context.DeadlineExceeded) {
 				s.log.Error("MAIL FROM error (deferred)", err, "rcpt", to, "msg_id", msgID)
 			}
 			s.deliveryErr = s.endp.wrapErr(msgID, !s.opts.UTF8, "RCPT", err)

internal/storage/imapsql/imapsql.go

@@ -379,12 +379,12 @@ func (store *Storage) GetOrCreateIMAPAcct(username string) (backend.User, error)
 func (store *Storage) Lookup(ctx context.Context, key string) (string, bool, error) {
 	accountName, err := store.authNormalize(ctx, key)
 	if err != nil {
-		return "", false, nil
+		return "", false, err
 	}
 
 	usr, err := store.Back.GetUser(accountName)
 	if err != nil {
-		if err == imapsql.ErrUserDoesntExists {
+		if errors.Is(err, imapsql.ErrUserDoesntExists) {
 			return "", false, nil
 		}
 		return "", false, err

systemd.go

@@ -80,7 +80,7 @@ func setScmPassCred(sock *net.UnixConn) error {
 func systemdStatus(status SDStatus, desc string) {
 	sock, err := sdNotifySock()
 	if err != nil {
-		if err != ErrNoNotifySock {
+		if !errors.Is(err, ErrNoNotifySock) {
 			log.Println("systemd: failed to acquire notify socket:", err)
 		}
 		return
@@ -107,7 +107,7 @@ func systemdStatus(status SDStatus, desc string) {
 func systemdStatusErr(reportedErr error) {
 	sock, err := sdNotifySock()
 	if err != nil {
-		if err != ErrNoNotifySock {
+		if !errors.Is(err, ErrNoNotifySock) {
 			log.Println("systemd: failed to acquire notify socket:", err)
 		}
 		return