helper: eliminate commandContext replacement

This is done more cleanly by modifying Args in cmdF.

Signed-off-by: Ophestra <cat@gensokyo.uk>

helper/cmd_test.go

@@ -3,6 +3,7 @@ package helper_test
 import (
 	"context"
 	"errors"
+	"io"
 	"os"
 	"os/exec"
 	"testing"
@@ -10,9 +11,9 @@ import (
 	"git.gensokyo.uk/security/fortify/helper"
 )
 
-func TestDirect(t *testing.T) {
+func TestCmd(t *testing.T) {
 	t.Run("start non-existent helper path", func(t *testing.T) {
-		h := helper.NewDirect(context.Background(), "/nonexistent", argsWt, false, argF, nil, nil)
+		h := helper.NewDirect(context.Background(), "/proc/nonexistent", argsWt, false, argF, nil, nil)
 
 		if err := h.Start(); !errors.Is(err, os.ErrNotExist) {
 			t.Errorf("Start: error = %v, wantErr %v",
@@ -22,15 +23,17 @@ func TestDirect(t *testing.T) {
 
 	t.Run("valid new helper nil check", func(t *testing.T) {
 		if got := helper.NewDirect(context.TODO(), "fortify", argsWt, false, argF, nil, nil); got == nil {
-			t.Errorf("New(%q, %q) got nil",
+			t.Errorf("NewDirect(%q, %q) got nil",
 				argsWt, "fortify")
 			return
 		}
 	})
 
 	t.Run("implementation compliance", func(t *testing.T) {
-		testHelper(t, func(ctx context.Context, cmdF func(cmd *exec.Cmd), stat bool) helper.Helper {
-			return helper.NewDirect(ctx, "crash-test-dummy", argsWt, stat, argF, cmdF, nil)
-		})
+		testHelper(t, func(ctx context.Context, setOutput func(stdoutP, stderrP *io.Writer), stat bool) helper.Helper {
+			return helper.NewDirect(ctx, os.Args[0], argsWt, stat, argF, func(cmd *exec.Cmd) {
+				setOutput(&cmd.Stdout, &cmd.Stderr)
+			}, nil)
+		}, "exec")
 	})
 }