stylus/popup/preinit.js

/* global API */// msg.js
/* global URLS waitForTabUrl */// toolbox.js
'use strict';

const ABOUT_BLANK = 'about:blank';
/* exported preinit */
const preinit = (async () => {
  let [tab] = await browser.tabs.query({currentWindow: true, active: true});
  if (!chrome.app && tab.status === 'loading' && tab.url === ABOUT_BLANK) {
    tab = await waitForTabUrl(tab);
  }
  const frames = sortTabFrames(await browser.webNavigation.getAllFrames({tabId: tab.id}));
  let url = tab.pendingUrl || tab.url || ''; // new Chrome uses pendingUrl while connecting
  if (url === 'chrome://newtab/' && !URLS.chromeProtectsNTP) {
    url = frames[0].url || '';
  }
  if (!URLS.supported(url)) {
    url = '';
    frames.length = 1;
  }
  frames[0].url = url;
  const uniqFrames = frames.filter(f => f.url && !f.isDupe);
  const styles = await Promise.all(uniqFrames.map(async ({url}) => ({
    url,
    styles: await getStyleDataMerged(url),
  })));
  return {frames, styles, url};
})();

/* Merges the extra props from API into style data.
 * When `id` is specified returns a single object otherwise an array */
async function getStyleDataMerged(url, id) {
  const styles = (await API.styles.getByUrl(url, id))
    .map(r => Object.assign(r.style, r));
  return id ? styles[0] : styles;
}

/** @param {browser.webNavigation._GetAllFramesReturnDetails[]} frames */
function sortTabFrames(frames) {
  const unknown = new Map(frames.map(f => [f.frameId, f]));
  const known = new Map([[0, unknown.get(0) || {frameId: 0, url: ''}]]);
  unknown.delete(0);
  let lastSize = 0;
  while (unknown.size !== lastSize) {
    for (const [frameId, f] of unknown) {
      if (known.has(f.parentFrameId)) {
        unknown.delete(frameId);
        if (!f.errorOccurred) known.set(frameId, f);
        if (f.url === ABOUT_BLANK) f.url = known.get(f.parentFrameId).url;
      }
    }
    lastSize = unknown.size; // guard against an infinite loop due to a weird frame structure
  }
  const sortedFrames = [...known.values(), ...unknown.values()];
  const urls = new Set([ABOUT_BLANK]);
  for (const f of sortedFrames) {
    if (!f.url) f.url = '';
    f.isDupe = urls.has(f.url);
    urls.add(f.url);
  }
  return sortedFrames;
}