Function nameFor

example/tests/gm_download_test.js:120–122

(label, ext = "bin")

  // want them to (the conflictAction "overwrite" test reuses a fixed name).
  const RUN_TAG = Date.now().toString(36) + "-" + Math.floor(Math.random() * 36 ** 4).toString(36).padStart(4, "0");
  function nameFor(label, ext = "bin") {
    return getPrefix() + RUN_TAG + "-" + label.replace(/[^a-zA-Z0-9_-]+/g, "_") + "." + ext;
  }

  // ---------- A small dataset built once, reused everywhere ----------
  // 1x1 transparent PNG (67 bytes).