use fmt.Errorf(...) instead of errors.New(fmt.Sprintf(...))

cli/util/ioutil.go

@@ -3,7 +3,6 @@ package util
 import (
 	"bytes"
 	"encoding/json"
-	"errors"
 	"fmt"
 	"io"
 	"os"
@@ -50,7 +49,7 @@ func SerializeToStdout(data interface{}, cfg *CliConfig) error {
 func namedTemplateToStdout(data interface{}, cfg *CliConfig) (err error) {
 	template := cfg.templateRepository.Get(cfg.Template)
 	if template == nil {
-		err = errors.New(fmt.Sprintf("no template with name '%s'", cfg.Template))
+		err = fmt.Errorf("no template with name '%s'", cfg.Template)
 		return
 	}
 

cli/util/template_repository.go

@@ -1,7 +1,6 @@
 package util
 
 import (
-	"errors"
 	"fmt"
 	"text/template"
 
@@ -44,7 +43,7 @@ func TemplateRepositoryFromConfig() (t TemplateRepository, err error) {
 		tpl := template.New(name)
 
 		if _, e := tpl.Parse(s); e != nil {
-			err = errors.New(fmt.Sprintf("syntax error in template '%s': %v", name, e))
+			err = fmt.Errorf("syntax error in template '%s': %v", name, e)
 			return
 		}
 

lib/auth/authenticator.go

@@ -1,7 +1,6 @@
 package auth
 
 import (
-	"errors"
 	"fmt"
 	"net/http"
 	"net/url"
@@ -64,7 +63,7 @@ func (a *authenticator) fetchTokenJWT(c *Challenge) (decodedResponse authRespons
 	}
 
 	if authResponse.StatusCode != http.StatusOK {
-		err = errors.New(fmt.Sprintf("authentication against auth server failed with code %d", authResponse.StatusCode))
+		err = fmt.Errorf("authentication against auth server failed with code %d", authResponse.StatusCode)
 		return
 	}
 
@@ -85,7 +84,7 @@ func (a *authenticator) fetchTokenOAuth2(c *Challenge, refreshToken string) (dec
 	}
 
 	if authResponse.StatusCode != http.StatusOK {
-		err = errors.New(fmt.Sprintf("OAuth2 authentication against auth server failed with code %d", authResponse.StatusCode))
+		err = fmt.Errorf("OAuth2 authentication against auth server failed with code %d", authResponse.StatusCode)
 		return
 	}
 

lib/auth/challenge.go

@@ -1,7 +1,6 @@
 package auth
 
 import (
-	"errors"
 	"fmt"
 	"net/url"
 	"regexp"
@@ -22,7 +21,7 @@ func ParseChallenge(challengeHeader string) (ch *Challenge, err error) {
 	match := challengeRegex.FindAllStringSubmatch(challengeHeader, -1)
 
 	if len(match) != 1 {
-		err = errors.New(fmt.Sprintf("malformed challenge header: '%s'", challengeHeader))
+		err = fmt.Errorf("malformed challenge header: '%s'", challengeHeader)
 	} else {
 		var parsedRealm *url.URL
 		parsedRealm, err = url.Parse(match[0][1])

lib/link_to_next_header.go

@@ -1,7 +1,6 @@
 package lib
 
 import (
-	"errors"
 	"fmt"
 	"net/url"
 	"regexp"
@@ -13,7 +12,7 @@ func parseLinkToNextHeader(header string) (nextUrl *url.URL, err error) {
 	match := linkToNextHeaderRegexp.FindAllStringSubmatch(header, -1)
 
 	if len(match) != 1 {
-		err = errors.New(fmt.Sprintf("malformed link header: %s", header))
+		err = fmt.Errorf("malformed link header: %s", header)
 		return
 	}