Github PR bookmarklet: button to toggle height on file diff

github_toggle_height_pr.js

javascript:
document.querySelectorAll('.file').forEach(function (fileDiff) {
  var div, fa;

  div = document.createElement('div'); 
  div.className = 'btn btn-sm'; 
  div.textContent = 'TOGGLE';
  div.addEventListener('click', function (event) { 
    const fileActions = event.target.parentElement;
    const fileHeader = fileActions.parentElement;
    const file = fileHeader.parentElement;
    const blobWrapper = file.querySelector('.blob-wrapper');
    console.log('Toggle height on', blobWrapper);
    blobWrapper.style.height = (blobWrapper.style.height === '' ? '0px' : ''); 
  });
  
  fa = fileDiff.querySelector('.file-actions'); 
  fa.insertBefore(div, fa.children[0]);
});

Looks like there is a bug where the event handler is cleaned up when switching between PR tabs. :(

Well well well, looks like github released their own "expand/collapse" button. >:(

... It's probably more performant than my JS.