feature: return KError instead of errors in AlterConfigs and Describe…

…Configs

admin.go

@@ -666,11 +666,8 @@ func (ca *clusterAdmin) DescribeConfig(resource ConfigResource) ([]ConfigEntry,
 
 	for _, rspResource := range rsp.Resources {
 		if rspResource.Name == resource.Name {
-			if rspResource.ErrorMsg != "" {
-				return nil, errors.New(rspResource.ErrorMsg)
-			}
 			if rspResource.ErrorCode != 0 {
-				return nil, KError(rspResource.ErrorCode)
+				return nil, &DescribeConfigError{Err: KError(rspResource.ErrorCode), ErrMsg: rspResource.ErrorMsg}
 			}
 			for _, cfgEntry := range rspResource.Configs {
 				entries = append(entries, *cfgEntry)
@@ -721,11 +718,8 @@ func (ca *clusterAdmin) AlterConfig(resourceType ConfigResourceType, name string
 
 	for _, rspResource := range rsp.Resources {
 		if rspResource.Name == name {
-			if rspResource.ErrorMsg != "" {
-				return errors.New(rspResource.ErrorMsg)
-			}
 			if rspResource.ErrorCode != 0 {
-				return KError(rspResource.ErrorCode)
+				return &AlterConfigError{Err: KError(rspResource.ErrorCode), ErrMsg: rspResource.ErrorMsg}
 			}
 		}
 	}

alter_configs_response.go

@@ -1,13 +1,29 @@
 package sarama
 
-import "time"
+import (
+	"fmt"
+	"time"
+)
 
 // AlterConfigsResponse is a response type for alter config
 type AlterConfigsResponse struct {
 	ThrottleTime time.Duration
 	Resources    []*AlterConfigsResourceResponse
 }
 
+type AlterConfigError struct {
+	Err    KError
+	ErrMsg string
+}
+
+func (c *AlterConfigError) Error() string {
+	text := c.Err.Error()
+	if c.ErrMsg != "" {
+		text = fmt.Sprintf("%s - %s", text, c.ErrMsg)
+	}
+	return text
+}
+
 // AlterConfigsResourceResponse is a response type for alter config resource
 type AlterConfigsResourceResponse struct {
 	ErrorCode int16

describe_configs_response.go

@@ -34,6 +34,19 @@ const (
 	SourceDefault
 )
 
+type DescribeConfigError struct {
+	Err    KError
+	ErrMsg string
+}
+
+func (c *DescribeConfigError) Error() string {
+	text := c.Err.Error()
+	if c.ErrMsg != "" {
+		text = fmt.Sprintf("%s - %s", text, c.ErrMsg)
+	}
+	return text
+}
+
 type DescribeConfigsResponse struct {
 	Version      int16
 	ThrottleTime time.Duration