Support structured error response

cloudapi/client.go

@@ -144,7 +144,7 @@ func (c *Client) do(req *http.Request, v interface{}, attempt int) (retry bool,
 		return false, err
 	}
 
-	if err = checkResponse(resp); err != nil {
+	if err = CheckResponse(resp); err != nil {
 		return false, err
 	}
 
@@ -157,7 +157,7 @@ func (c *Client) do(req *http.Request, v interface{}, attempt int) (retry bool,
 	return false, err
 }
 
-func checkResponse(r *http.Response) error {
+func CheckResponse(r *http.Response) error {
 	if r == nil {
 		return errUnknown
 	}

output/cloud/expv2/metrics_client.go

@@ -13,6 +13,7 @@ import (
 	"github.com/sirupsen/logrus"
 	"google.golang.org/protobuf/proto"
 
+	"go.k6.io/k6/cloudapi"
 	"go.k6.io/k6/lib/consts"
 	"go.k6.io/k6/output/cloud/expv2/pbcloud"
 )
@@ -98,8 +99,9 @@ func (mc *MetricsClient) Push(ctx context.Context, referenceID string, samples *
 	defer func() {
 		_ = resp.Body.Close()
 	}()
-	if resp.StatusCode != http.StatusOK {
-		return fmt.Errorf("response got an unexpected status code: %s", resp.Status)
+
+	if err := cloudapi.CheckResponse(resp); err != nil {
+		return err
 	}
 	mc.logger.WithField("t", time.Since(start)).WithField("size", len(b)).
 		Debug("Pushed the collected metrics to the Cloud service")

output/cloud/expv2/metrics_client_test.go

@@ -12,6 +12,7 @@ import (
 
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
+	"go.k6.io/k6/cloudapi"
 	"go.k6.io/k6/lib/testutils"
 	"go.k6.io/k6/output/cloud/expv2/pbcloud"
 )
@@ -93,3 +94,31 @@ func TestMetricsClientPushError(t *testing.T) {
 	err := mc.Push(context.TODO(), "test-ref-id", nil)
 	assert.ErrorContains(t, err, "fake generated error")
 }
+
+func TestMetricsClientPushStructuredError(t *testing.T) {
+	t.Parallel()
+
+	exp := cloudapi.ErrorResponse{Code: 1, Message: "test message"}
+
+	httpClientMock := func(_ *http.Request) (*http.Response, error) {
+		b := `{"error":{"code":1,"message":"test message"}}`
+		r := &http.Response{
+			StatusCode: http.StatusBadRequest,
+			Body:       io.NopCloser(bytes.NewBuffer([]byte(b))),
+		}
+		exp.Response = r
+		return r, nil
+	}
+
+	mc := MetricsClient{
+		httpClient: httpDoerFunc(httpClientMock),
+		pushBufferPool: sync.Pool{
+			New: func() interface{} {
+				return &bytes.Buffer{}
+			},
+		},
+	}
+
+	err := mc.Push(context.TODO(), "test-ref-id", nil)
+	assert.Equal(t, exp, err)
+}