Make Result.Error a string

lib/attack.go

@@ -1,7 +1,6 @@
 package vegeta
 
 import (
-	"errors"
 	"io/ioutil"
 	"net/http"
 	"time"
@@ -50,13 +49,14 @@ func hit(req *http.Request, res chan Result) {
 		Timestamp: began,
 		Timing:    time.Since(began),
 		BytesOut:  uint64(req.ContentLength),
-		Error:     err,
 	}
-	if err == nil {
+	if err != nil {
+		result.Error = err.Error()
+	} else {
 		result.Code = uint16(r.StatusCode)
 		if body, err := ioutil.ReadAll(r.Body); err != nil {
 			if result.Code < 200 || result.Code >= 300 {
-				result.Error = errors.New(string(body))
+				result.Error = string(body)
 			}
 		} else {
 			result.BytesIn = uint64(len(body))

lib/metrics.go

@@ -37,8 +37,8 @@ func NewMetrics(results []Result) *Metrics {
 		if result.Code >= 200 && result.Code < 300 {
 			m.TotalSuccess++
 		}
-		if result.Error != nil {
+		if result.Error != "" {
-			errorSet[result.Error.Error()] = struct{}{}
+			errorSet[result.Error] = struct{}{}
 		}
 	}
 

lib/metrics_test.go

@@ -1,16 +1,15 @@
 package vegeta
 
 import (
-	"errors"
 	"testing"
 	"time"
 )
 
 func TestNewMetrics(t *testing.T) {
 	m := NewMetrics([]Result{
-		Result{500, time.Now(), 100 * time.Millisecond, 10, 30, errors.New("Internal server error")},
+		Result{500, time.Now(), 100 * time.Millisecond, 10, 30, "Internal server error"},
-		Result{200, time.Now(), 20 * time.Millisecond, 20, 20, nil},
+		Result{200, time.Now(), 20 * time.Millisecond, 20, 20, ""},
-		Result{200, time.Now(), 30 * time.Millisecond, 30, 10, nil},
+		Result{200, time.Now(), 30 * time.Millisecond, 30, 10, ""},
 	})
 
 	for field, values := range map[string][]float64{

lib/results.go

@@ -15,7 +15,7 @@ type Result struct {
 	Timing    time.Duration
 	BytesOut  uint64
 	BytesIn   uint64
-	Error     error
+	Error     string
 }
 
 // Results is a slice of Result structs with encoding,

lib/results_test.go

@@ -9,9 +9,9 @@ import (
 
 func TestEncoding(t *testing.T) {
 	results := Results{
-		Result{200, time.Now(), 100 * time.Millisecond, 10, 30, nil},
+		Result{200, time.Now(), 100 * time.Millisecond, 10, 30, ""},
-		Result{200, time.Now(), 20 * time.Millisecond, 20, 20, nil},
+		Result{200, time.Now(), 20 * time.Millisecond, 20, 20, ""},
-		Result{200, time.Now(), 30 * time.Millisecond, 30, 10, nil},
+		Result{200, time.Now(), 30 * time.Millisecond, 30, 10, ""},
 	}
 	buffer := &bytes.Buffer{}