Tampermonkey script to override the build message function in slack to replace JIRA issue IDs with links.

linkJiraIssuesInSlack.js

// ==UserScript==
// @name         Slack to Jira links
// @namespace    ca.arndt.dan.slack.jiralinks
// @version      1
// @description  JIRA links in Slack
// @include      https://*.slack.com/*
// @run-at document-end
// @grant unsafeWindow
// ==/UserScript==

var jiraBaseUrl = "https://analyzere.atlassian.net/";
var jiraProjects = ["ARE", "PS", "TP", "CSD"];

var jiraIssuePath = "browse/";

jiraLink = function(str) {
    const regex = /<span class="message_body">(.*)<\/span>/g;
    var msg = str;
    // console.log(str.replace(regex, function(a,b){
    //    return jiraLink(b);
    //}));
    var regEx;
    var dealWithMatch = function(match, p1, p2) {
    console.log("Matched: " + match);
        if (match.slice(0, 3) === "%2F") {
            return match;
        }
        if (match.slice(2, 3) === "/") {
            return match;
        }
        return p1 + "<a href='" + jiraBaseUrl + jiraIssuePath + p2 + "'>"+ p2+"</a>";
    };

    jiraProjects.forEach(function (project) {
        regEx = new RegExp("(...)("+project+"-[0-9]+)","gim");
        msg = msg.replace(regEx, dealWithMatch);
    });
    return msg;
};

var oldBuildMsgHTML = TS.templates.builders.msgs.buildHTML;

TS.templates.builders.msgs.buildHTML = function(obj) {
    var returnValue = oldBuildMsgHTML(obj);
    return jiraLink(returnValue);
};