debian-mirror-gitlab/app/assets/javascripts/lib/utils/file_upload.js

export default (buttonSelector, fileSelector) => {
  const btn = document.querySelector(buttonSelector);
  const fileInput = document.querySelector(fileSelector);

  if (!btn || !fileInput) return;

  const form = btn.closest('form');

  btn.addEventListener('click', () => {
    fileInput.click();
  });

  fileInput.addEventListener('change', () => {
    form.querySelector('.js-filename').textContent = fileInput.value.replace(/^.*[\\\/]/, ''); // eslint-disable-line no-useless-escape
  });
};