GitHub Pull Request against the current branch

!README.md

README

GitHub helpfully prompts you to create a pull request after pushing a new branch. Unhelpfully, it always suggests PRing against master (or develop or whatever your main branch is). This Tampermonkey/ Greasemonkey script adds a "Compare & pull request (current branch)" button that will bring you to the PR creation page already comparing against the branch you're currently on.

How To:

1. Install the Tampermonkey extension for Chrome or Greasemonkey extension for Firefox
2. Restart your browser
3. Click on the "Raw" button of the github-pr-against-current-br.user.js file below
4. Tampermonkey/Greasemonkey should pick up the fact that it's a *.user.js file and prompt you to install. Click "Install"
5. Push an update to a branch (or push a new branch)
6. On GitHub.com, navigate to the tree you want to PR against using the "Branch" dropdown (if you're already on the branch, refresh the page)
7. Click on "Pull request (current branch)"
8. Save time

TODO:

• Get it to listen to changes to the DOM so that it can add itself when GitHub detects a branch (currently requires the branch to be available on page load)
• Create a Chrome extension
• Create a Firefox extension
• Encourage GitHub to add this functionality natively

github-pr-against-current-br.user.js

// ==UserScript==
// @name        github-pr-against-current-br
// @namespace   mklaber
// @description Adds a Compare & pull request button that compares to the current branch
// @include     https://github.com/*/*/tree/*
// @version     1.1
// @grant       none
// ==/UserScript==

function log(str) {
	if (typeof debug !== 'undefined') { debug(str); }
	if (typeof GM_log !== 'undefined') { GM_log(str); return true; }
	else if (typeof console !== 'undefined' && console.log) { console.log(str); return true; }
	return false;
}

function logError(category, x) {
	msg = "Error (" + category + ") - " +  x.name + ' - ' + x.message + ' in file <' + x.fileName + '> on line ' + x.lineNumber + ' while viewing ' + page;
	log(msg);
}

function $q(selector, root, multi) {
  root = root || document;
  if (multi) {
    return Array.from(root.querySelectorAll(selector));
  } else {
    return root.querySelector(selector);
  }
}

function getBranch() {
	return $q('#branch').value;
}

function getRecentBranches() {
	return $q('.RecentBranches .RecentBranches-item', document, true);
}

function addButtonToBranch(branch) {
	var a = $q('a.btn', branch);
	var currentBranchName = getBranch();
	log(currentBranchName);
	var newBtn = a.cloneNode();
	newBtn.innerHTML = a.innerHTML.replace('pull request', 'pull request (current branch)');
	newBtn.style.marginLeft = '5px';
	newBtn.href = newBtn.href.replace(/\/compare\//, '/compare/' + currentBranchName + '...');
	branch.insertBefore(newBtn, a);
}

function getRecentBranchUpdatePanel() {
	return $q('.js-updatable-content[data-url$="recently_touched_branches_list"] .RecentBranches');
}

function findAndUpdateBranches() {
	var branches = getRecentBranches();
	branches.forEach(addButtonToBranch);
}

try {
	setTimeout(function() {
		findAndUpdateBranches();
	}, 1000);
} catch(err) {
	logError('github', err);
}