Add a link to a GitHub repo's first commit
Version au
// ==UserScript==
// @name GitHub First Commit
// @description Add a link to a GitHub repo's first commit
// @author chocolateboy
// @copyright chocolateboy
// @version 2.6.0
// @namespace https://github.com/chocolateboy/userscripts
// @license GPL: https://www.gnu.org/copyleft/gpl.html
// @include https://github.com/
// @include https://github.com/*
// @require https://code.jquery.com/jquery-3.5.1.slim.min.js
// @require https://cdn.jsdelivr.net/gh/eclecto/jQuery-onMutate@79bbb2b8caccabfc9b9ade046fe63f15f593fef6/src/jquery.onmutate.min.js
// @grant GM_log
// @inject-into auto
// ==/UserScript==
// XXX note: the unused grant is a workaround for a Greasemonkey bug:
// https://github.com/greasemonkey/greasemonkey/issues/1614
const COMMIT_BAR = 'div.js-details-container[data-issue-and-pr-hovercards-enabled] > *:last ul'
const FIRST_COMMIT_LABEL = '<span aria-label="First commit"><strong>1st</strong> commit</span>'
// this function extracts the URL of the repo's first commit and navigates to it.
// it is based on code by several developers, a list of whom can be found here:
// https://github.com/FarhadG/init#contributors
//
// XXX it doesn't work on private repos. a way to do that can be found here,
// but it requires an authentication token:
// https://gist.github.com/simonewebdesign/a70f6c89ffd71e6ba4f7dcf7cc74ccf8
function openFirstCommit (user, repo) {
return fetch(`https://api.github.com/repos/${user}/${repo}/commits`)
// the `Link` header has additional URLs for paging.
// parse the original JSON for the case where no other pages exist
.then(res => Promise.all([res.headers.get('link'), res.json()]))
.then(([link, commits]) => {
if (link) {
// the link header contains two URLs and has the following
// format (wrapped for readability):
//
// <https://api.github.com/repositories/1234/commits?page=2>;
// rel="next",
// <https://api.github.com/repositories/1234/commits?page=9>;
// rel="last"
// extract the URL of the last page (commits are ordered in
// reverse chronological order, like the CLI, so the oldest
// commit is on the last page)
const lastPage = link.match(/^.+?<([^>]+)>;/)[1]
// fetch the last page of results
return fetch(lastPage).then(res => res.json())
}
// if there's no link, we know we're on the only page
return commits
})
// get the last commit and extract the target URL
.then(commits => commits[commits.length - 1].html_url)
// navigate there
.then(url => location.href = url)
}
// add the "First commit" link as the last child of the commit bar
function addLink ($commitBar) {
let $firstCommit = $commitBar.find('#first-commit')
if ($firstCommit.length) {
return
}
/*
* This is the first LI in the commit bar (UL), which we clone to create the
* "First commit" widget.
*
* <li class="ml-3">
* <a data-pjax="" href="/foo/bar/commits/master" class="link-gray-dark no-underline">
* <svg height="16">...</svg>
*
* <span class="d-none d-sm-inline">
* <strong>42</strong>
* <span aria-label="Commits on master">commits</span>
* </span>
* </a>
* </li>
*/
// create it
$firstCommit = $commitBar
.find('li')
.eq(0)
.clone()
.attr('id', 'first-commit')
const $link = $firstCommit
.find('a')
.removeAttr('href')
.css('cursor', 'pointer')
const $label = $(FIRST_COMMIT_LABEL)
$link.find('> span').empty().append($label)
const [user, repo] = $('meta[name="octolytics-dimension-repository_network_root_nwo"]')
.attr('content')
.split('/')
const oldLabelHtml = $label.html()
// restore the original label so it has the correct value if we navigate
// back to the repo page without making a new request (e.g. via the back
// button)
$(window).on('unload', () => {
$label.html(oldLabelHtml)
})
$link.on('click', () => {
$label.text('Loading...')
openFirstCommit(user, repo)
return false
})
$commitBar.append($firstCommit)
}
$.onCreate(COMMIT_BAR, addLink, true /* multi */)