Simple & hackish "Expand all diffs" button for Github PRs

github.expand-all-diffs.userscript.js

// ==UserScript==
// @name        Github Expand All Button
// @namespace   mdziekon_github_expandall
// @include     /http(s)*://(.*?)github.com/(.*?)/pull/(.*?)/
// @version     1
// @grant       none
// ==/UserScript==

let evtListener;

function onExpandAllClicked() {
    const event = new MouseEvent(
        "click",
        {
            view: window,
            bubbles: true,
            cancelable: true
        }
    );

    const $expandAllButton = document.querySelector("#expand-all-diffs-container button");
    $expandAllButton.textContent = "(All diffs expanded)";
    $expandAllButton.removeEventListener("click", evtListener);

    const $expandButtons = document.querySelectorAll(".load-diff-button");

    $expandButtons.forEach((node) => node.dispatchEvent(event));
}

function injectButton() {
    const $codeStats = document.querySelector(".diffbar-item.diffstat");

    if ($codeStats === null) {
        return;
    }

    const $expandAllContainer = document.createElement("div");
    $expandAllContainer.className = "diffbar-item";
    $expandAllContainer.id = "expand-all-diffs-container";
    const $expandAllButton = document.createElement("button");
    const $buttonText = document.createElement("strong");
    $buttonText.appendChild(document.createTextNode("Expand all diffs"));
    $expandAllButton.appendChild($buttonText);
    $expandAllButton.className = "btn-link muted-link";
    evtListener = $expandAllButton.addEventListener("click", onExpandAllClicked);

    $expandAllContainer.appendChild($expandAllButton);

    $codeStats.parentNode.insertBefore($expandAllContainer, $codeStats.nextSibling);
}

function hasExpandAllButton() {
    if (document.querySelector("#expand-all-diffs-container") !== null) {
        return;
    }

    injectButton();
}

setInterval(hasExpandAllButton, 2000);