stylus/background/usercss-install-helper.js

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JavaScript
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2020-10-06 10:49:43 +00:00
/* global API_METHODS openURL download URLS tabManager */
'use strict';
(() => {
const installCodeCache = {};
const clearInstallCode = url => delete installCodeCache[url];
const isContentTypeText = type => /^text\/(css|plain)(;.*?)?$/i.test(type);
// in Firefox we have to use a content script to read file://
const fileLoader = !chrome.app && (
async tabId =>
(await browser.tabs.executeScript(tabId, {file: '/content/install-hook-usercss.js'}))[0]);
const urlLoader =
async (tabId, url) => (
url.startsWith('file:') ||
tabManager.get(tabId, isContentTypeText.name) ||
isContentTypeText((await fetch(url, {method: 'HEAD'})).headers.get('content-type'))
) && download(url);
API_METHODS.getUsercssInstallCode = url => {
// when the installer tab is reloaded after the cache is expired, this will throw intentionally
const {code, timer} = installCodeCache[url];
clearInstallCode(url);
clearTimeout(timer);
return code;
};
// Faster installation on known distribution sites to avoid flicker of css text
chrome.webRequest.onBeforeSendHeaders.addListener(({tabId, url}) => {
openInstallerPage(tabId, url, {});
// Silently suppressing navigation like it never happened
return {redirectUrl: 'javascript:void 0'}; // eslint-disable-line no-script-url
}, {
urls: [
URLS.usoArchiveRaw + 'usercss/*.user.css',
'*://greasyfork.org/scripts/*/code/*.user.css',
'*://sleazyfork.org/scripts/*/code/*.user.css',
],
types: ['main_frame'],
}, ['blocking']);
// Remember Content-Type to avoid re-fetching of the headers in urlLoader as it can be very slow
chrome.webRequest.onHeadersReceived.addListener(({tabId, responseHeaders}) => {
const h = responseHeaders.find(h => h.name.toLowerCase() === 'content-type');
tabManager.set(tabId, isContentTypeText.name, h && isContentTypeText(h.value) || undefined);
}, {
urls: '%css,%css?*,%styl,%styl?*'.replace(/%/g, '*://*/*.user.').split(','),
types: ['main_frame'],
}, ['responseHeaders']);
tabManager.onUpdate(async ({tabId, url, oldUrl = ''}) => {
if (url.includes('.user.') &&
/^(https?|file|ftps?):/.test(url) &&
/\.user\.(css|styl)$/.test(url.split(/[#?]/, 1)[0]) &&
!oldUrl.startsWith(URLS.installUsercss)) {
const inTab = url.startsWith('file:') && Boolean(fileLoader);
const code = await (inTab ? fileLoader : urlLoader)(tabId, url);
if (/==userstyle==/i.test(code)) {
openInstallerPage(tabId, url, {code, inTab});
}
}
});
function openInstallerPage(tabId, url, {code, inTab} = {}) {
const newUrl = `${URLS.installUsercss}?updateUrl=${encodeURIComponent(url)}`;
if (inTab) {
browser.tabs.get(tabId).then(tab =>
openURL({
url: `${newUrl}&tabId=${tabId}`,
active: tab.active,
index: tab.index + 1,
openerTabId: tabId,
currentWindow: null,
}));
} else {
const timer = setTimeout(clearInstallCode, 10e3, url);
installCodeCache[url] = {code, timer};
chrome.tabs.update(tabId, {url: newUrl});
}
}
})();