test: nitpicks

Author: isometry

test/e2e/e2e_test.go

@@ -108,7 +108,7 @@ var _ = Describe("GitHub Token Manager", Ordered, func() {
 		cmd := exec.Command("ko", "build", "--local", "./cmd/manager")
 		output, err := utils.Run(cmd)
 		Expect(err).NotTo(HaveOccurred())
-		projectImage = string(output)[:len(output)-1] // Remove newline
+		projectImage = strings.TrimSpace(string(output))
 
 		if strings.HasPrefix(kubeContext, "kind-") {
 			By("loading the manager image to Kind")

test/utils/utils.go

@@ -17,6 +17,7 @@ limitations under the License.
 package utils
 
 import (
+	"bytes"
 	"context"
 	"crypto/rand"
 	"crypto/rsa"
@@ -44,12 +45,21 @@ func Run(cmd *exec.Cmd) ([]byte, error) {
 	cmd.Env = append(os.Environ(), "GO111MODULE=on")
 	command := strings.Join(cmd.Args, " ")
 	_, _ = fmt.Fprintf(ginkgo.GinkgoWriter, "running: %s\n", command)
-	output, err := cmd.Output()
+
+	var stdout, stderr bytes.Buffer
+	cmd.Stdout = &stdout
+	cmd.Stderr = &stderr
+
+	err := cmd.Run()
 	if err != nil {
-		return output, fmt.Errorf("%s failed with error: (%v) %s", command, err, string(output))
+		stderrStr := stderr.String()
+		if stderrStr != "" {
+			return stdout.Bytes(), fmt.Errorf("%s failed with error: (%v) stderr: %s", command, err, stderrStr)
+		}
+		return stdout.Bytes(), fmt.Errorf("%s failed with error: (%v)", command, err)
 	}
 
-	return output, nil
+	return stdout.Bytes(), nil
 }
 
 // LoadImageToKindCluster loads a local docker image to the kind cluster