chore(backend): refactor error checks

cmd/karma/main.go

@@ -3,6 +3,7 @@ package main
 import (
 	"compress/flate"
 	"context"
+	"errors"
 	"fmt"
 	"html/template"
 	"io/ioutil"
@@ -451,7 +452,7 @@ func serve(errorHandling pflag.ErrorHandling) error {
 		log.Info().Str("address", listener.Addr().String()).Msg("Starting HTTPS server")
 		go func() {
 			err := httpServer.ServeTLS(listener, config.Config.Listen.TLS.Cert, config.Config.Listen.TLS.Key)
-			if err != nil && err != http.ErrServerClosed {
+			if !errors.Is(err, http.ErrServerClosed) {
 				log.Error().Err(err).Msg("HTTPS server startup error")
 				quit <- syscall.SIGTERM
 			}
@@ -460,7 +461,7 @@ func serve(errorHandling pflag.ErrorHandling) error {
 		log.Info().Str("address", listener.Addr().String()).Msg("Starting HTTP server")
 		go func() {
 			err := httpServer.Serve(listener)
-			if err != nil && err != http.ErrServerClosed {
+			if !errors.Is(err, http.ErrServerClosed) {
 				log.Error().Err(err).Msg("HTTP server startup error")
 				quit <- syscall.SIGTERM
 			}

internal/uri/uri_test.go

@@ -5,6 +5,7 @@ import (
 	"compress/gzip"
 	"crypto/tls"
 	"crypto/x509"
+	"errors"
 	"io"
 	"net/http"
 	"net/http/httptest"
@@ -99,7 +100,7 @@ func readAll(source io.ReadCloser) (int64, error) {
 		got, err := source.Read(b)
 		readSize += int64(got)
 		if err != nil {
-			if err == io.EOF {
+			if errors.Is(err, io.EOF) {
 				return readSize, nil
 			}
 			return readSize, err