// ==UserScript==
// @name GitHub First Commit
// @description Add a link to a GitHub repo's first commit
// @author chocolateboy
// @copyright chocolateboy
// @version 2.7.1
// @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://cdn.jsdelivr.net/npm/cash-dom@8.1.0/dist/cash.min.js
// @grant GM_log
// @inject-into auto
// @downloadURL none
// ==/UserScript==
const COMMIT_BAR = 'div.js-details-container[data-issue-and-pr-hovercards-enabled] > *:last-child ul'
const FIRST_COMMIT_LABEL = '1st commit'
/*
* 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):
//
// ;
// rel="next",
// ;
// rel="last"
// extract the URL of the last page (commits are ordered in
// reverse chronological order, like the git CLI, so the oldest
// commit is on the last page)
// @ts-ignore
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 navigate to its target URL
.then(commits => {
location.href = commits[commits.length - 1].html_url
})
}
/*
* add the "First commit" link as the last child of the commit bar
*/
function run () {
const $commitBar = $(COMMIT_BAR)
// bail if it's not a repo page
if (!$commitBar.length) {
return
}
// delete (i.e. replace) the (possibly inert/unresponsive) widget if it
// already exists
$commitBar.find('#first-commit').remove()
/*
* This is the first LI in the commit bar (UL), which we clone to create the
* "First commit" widget.
*
*