helper: stub helper for tests

Signed-off-by: Ophestra Umiker <cat@ophivana.moe>

helper/export_test.go

@@ -0,0 +1,18 @@
+package helper
+
+import (
+	"os"
+	"os/exec"
+	"testing"
+)
+
+// replace execCommand to have the resulting *exec.Cmd launch TestHelperChildStub
+func ReplaceExecCommand(t *testing.T) {
+	t.Cleanup(func() {
+		execCommand = exec.Command
+	})
+
+	execCommand = func(name string, arg ...string) *exec.Cmd {
+		return exec.Command(os.Args[0], append([]string{"-test.run=TestHelperChildStub", "--", name}, arg...)...)
+	}
+}