Clean up github code for printing (including main view for readme print)

github-clean-layout-for-code-print.js

(() => {

  const flattenArray = (acc, cur) => acc = [...acc, ...cur]
  const queryElement = selector => document.querySelector(selector)
  const getAllChildren = elem => elem.children
  const removeElem = elem => elem && elem.parentElement.removeChild(elem);
  const removeClassFromElem = (elem, styleclass) => elem && elem.classList.remove(styleclass);
  const removeClassesFromElem = ([elem, styleclasses]) => styleclasses.forEach(styleclass => removeClassFromElem(elem, styleclass));
  const findAllChildrensExcept = (elemToRemoveExcept) => elemToRemoveExcept
    .map(([elem, keepChildrenQueries]) => [queryElement(elem), keepChildrenQueries.map(queryElement)])
	  .map(([elem, keepChildrenElems]) => [Array.from(getAllChildren(elem)), keepChildrenElems])
	  .map(([childrenElems, keepChildrenElems]) => childrenElems.filter(elem => !keepChildrenElems.includes(elem)))
	  .reduce(flattenArray, [])


  const elemsToBeRemovedSelectors = [
    'body > div.application-main > div > main > div.container-lg.clearfix.new-discussion-timeline.experiment-repo-nav.p-responsive > div > div.Box.Box--condensed.d-flex.flex-column.flex-shrink-0',
    'body > div.application-main > div > main > div.pagehead.repohead.instapaper_ignore.readability-menu.experiment-repo-nav.pt-0.pt-lg-4',
    'body > div.footer.container-lg.width-full.p-responsive',
    'body > div.position-relative.js-header-wrapper',
    'body > div.application-main > div > main > div > div > div > div.Box-header.py-2.d-flex.flex-column.flex-shrink-0.flex-md-row.flex-md-items-center',
    'body > div.application-main > div > main > div > div > div.d-flex.flex-items-start.flex-shrink-0.pb-3.flex-column.flex-md-row > span',
    'body > div.application-main > div > main > div > div > div.d-flex.flex-items-start.flex-shrink-0.pb-3.flex-column.flex-md-row > div',
    'body > div.footer.container-lg.width-full.px-3',
    '#js-repo-pjax-container > div.pagehead.repohead.instapaper_ignore.readability-menu.experiment-repo-nav'
  ];
  
  const elemsToRemoveAllChildrenElemsExcept = [
    [
      '#js-repo-pjax-container > div.container-lg.clearfix.new-discussion-timeline.experiment-repo-nav.px-3 > div',
      ['#readme']
    ],
  ];

  const elemSelectorsWithClassesToBeRemoved = [
    [
      'body > div.application-main > div > main > div > div > div.d-flex.flex-items-start.flex-shrink-0.pb-3.flex-column.flex-md-row',
      ['pb-3']
    ]
  ];
  
  elemsToBeRemovedSelectors
    .map(queryElement)
    .forEach(removeElem);

  elemSelectorsWithClassesToBeRemoved
    .map(([selector, styleClasses]) => ([queryElement(selector), styleClasses]))
    .forEach(removeClassesFromElem);
  
  removeAllChildrenExcept(elemsToRemoveAllChildrenElemsExcept)
    .forEach(removeElem)
})();