loader revisited

client/loader/runner.go

@@ -0,0 +1,34 @@
+package loader
+
+import (
+	"context"
+	"errors"
+	"os"
+	"os/exec"
+)
+
+// uiRunner executes the standalone UI artifact and returns its exit code.
+type uiRunner interface {
+	Run(context.Context, string) (int, error)
+}
+
+type execRunner struct{}
+
+func (execRunner) Run(ctx context.Context, path string) (int, error) {
+	cmd := exec.CommandContext(ctx, path)
+	cmd.Stdout = os.Stdout
+	cmd.Stderr = os.Stderr
+	cmd.Stdin = os.Stdin
+
+	err := cmd.Run()
+	if err == nil {
+		return 0, nil
+	}
+
+	var exitErr *exec.ExitError
+	if errors.As(err, &exitErr) {
+		return exitErr.ExitCode(), nil
+	}
+
+	return -1, err
+}