Creates a floating badge of the sum on the tickets when you highlight multiple

jira-sum-highlighted.user.js

// ==UserScript==
// @name         Jira Sum Highlighted
// @author       Jonathan Gawrych
// @match        https://goreact.atlassian.net/*
// @icon         https://www.google.com/s2/favicons?sz=64&domain=atlassian.net
// @grant        none
// @run-at       document-idle
// ==/UserScript==

(function doit() {
    'use strict';

    if (typeof GH === 'undefined') {
        // We aren't initalized yet. Wait for a bit
        setTimeout(doit, 1000);
        return;
    }

    // Don't run on apages without the selection managaer
    if (GH.IssueSelectionManager.prototype.handleIssueClick == null) {
        return;
    }

    const hoverSelectionBadgeElement = document.createElement('SPAN');
    hoverSelectionBadgeElement.className = 'aui-badge';
    hoverSelectionBadgeElement.style.position = 'absolute';
    hoverSelectionBadgeElement.style.top = 0;
    hoverSelectionBadgeElement.style.right = 0;
    hoverSelectionBadgeElement.style.transform = 'translate(50%, -50%)';

    // Hook when you click on a jira ticket
    GH.IssueSelectionManager.prototype.handleIssueClick = ((oldFn) => {
        return function monkeyPatch(...args) {
            const result = oldFn.apply(this, args);
            // Get the selected issues
            const selected = this.getSelectedIssuesInOrder();

            // If one or zero issues are selected, remove our summary badge
            if (selected.length <= 1) {
                hoverSelectionBadgeElement.remove();
                return result;
            }

            // Otherwise, we need to calculate the sum. Get all issues.
            const issuesByKey = Object.assign.apply(Object, [{}].concat(
                GH.BacklogModel.getAllIssueListsNew().map(
                    (list) => list.data.issueByKey
            )));
            // Map them to mapped to the estimations and add it together
            const estimations = selected.map((key) => issuesByKey[key].estimateStatistic.statFieldValue.value ?? 0);
            const sumEstimations = Math.round(estimations.reduce((a, b) => a + b) * 10) / 10;
            hoverSelectionBadgeElement.innerText = sumEstimations;

            const firstSelectedElement = document.querySelector(`[data-issue-key="${selected[0]}"]`);
            firstSelectedElement.appendChild(hoverSelectionBadgeElement);
            return result;
        };
    })(GH.IssueSelectionManager.prototype.handleIssueClick);
})();