internal/helper: relocate from helper

This package is ugly and is pending removal only kept alive by xdg-dbus-proxy.

Its exported symbols are made available until v0.4.0 where it will be removed for #24.

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

internal/helper/cmd_test.go

@@ -0,0 +1,40 @@
+package helper_test
+
+import (
+	"context"
+	"errors"
+	"io"
+	"os"
+	"os/exec"
+	"testing"
+
+	"hakurei.app/container"
+	"hakurei.app/internal/helper"
+)
+
+func TestCmd(t *testing.T) {
+	t.Run("start non-existent helper path", func(t *testing.T) {
+		h := helper.NewDirect(t.Context(), container.Nonexistent, argsWt, false, argF, nil, nil)
+
+		if err := h.Start(); !errors.Is(err, os.ErrNotExist) {
+			t.Errorf("Start: error = %v, wantErr %v",
+				err, os.ErrNotExist)
+		}
+	})
+
+	t.Run("valid new helper nil check", func(t *testing.T) {
+		if got := helper.NewDirect(t.Context(), "hakurei", argsWt, false, argF, nil, nil); got == nil {
+			t.Errorf("NewDirect(%q, %q) got nil",
+				argsWt, "hakurei")
+			return
+		}
+	})
+
+	t.Run("implementation compliance", func(t *testing.T) {
+		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)
+		})
+	})
+}