add missing cmd.go

Author: denik

internal/testutil/cmd.go

@@ -0,0 +1,26 @@
+package testutil
+
+import (
+	"bytes"
+	"os"
+	"os/exec"
+
+	"github.com/stretchr/testify/require"
+)
+
+func RunCommand(t TestingT, name string, args ...string) {
+	cmd := exec.Command(name, args...)
+	cmd.Stdout = os.Stdout
+	cmd.Stderr = os.Stderr
+	require.NoError(t, cmd.Run())
+}
+
+func CaptureCommandOutput(t TestingT, name string, args ...string) string {
+	cmd := exec.Command(name, args...)
+	var stdout bytes.Buffer
+	cmd.Stdout = &stdout
+	cmd.Stderr = os.Stderr
+	err := cmd.Run()
+	require.NoError(t, err)
+	return stdout.String()
+}