add loadCss common helper function

.eslintrc.json

@@ -26,6 +26,7 @@
           "HTMLMetaElement",
           "HTMLParagraphElement",
           "HTMLSpanElement",
+          "HTMLStyleElement",
           "HTMLUListElement",
           "Promise",
           "Response",

src/js/changelog-topic.js

@@ -1,8 +1,7 @@
 import ChangelogService from "./changelog/ChangelogService";
+import { loadCss } from "./common";
 
-const style = document.createElement("style");
-document.getElementsByTagName("head")[0].appendChild(style);
-style.appendChild(document.createTextNode(require("../css/changelog.css")));
+loadCss(require("../css/changelog.css"));
 
 /** 
  * @param {URL} url

src/js/changelog.js

@@ -1,9 +1,8 @@
 import ChangelogList from "./changelog/ChangelogList";
 import ChangelogService from "./changelog/ChangelogService";
+import { loadCss } from "./common";
 
-const style = document.createElement("style");
-document.getElementsByTagName("head")[0].appendChild(style);
-style.appendChild(document.createTextNode(require("../css/changelog.css")));
+loadCss(require("../css/changelog.css"));
 
 /** @type {string} */
 const apiBase = document.location.hostname.match(/(localhost|127\.0\.0\.1)/) ? "" : "https://bitrise.io";
@@ -42,4 +41,4 @@ if (queryLAstVisit) {
 changelogLoadMoreButton.remove();
 changelogService.loadTopics("/changelog.json").then(topics => {
   changelogList.render(topics, lastVisitedDate);
-});
+});});

src/js/common.js

@@ -83,4 +83,25 @@ function fancyConsoleLog(text) {
   console.log('%c' + text, tpl + 'white');
 }
 
-export {capitalize, icaseEqual, icaseIncludes, getElementTextContent, getFirstElementByClassname, getMetaTag, setMetaContent, fancyConsoleLog};
+/**
+ * @param {string} cssData 
+ * @returns {HTMLStyleElement}
+ */
+function loadCss(cssData) {
+  const style = document.createElement("style");
+  document.getElementsByTagName("head")[0].appendChild(style);
+  style.appendChild(document.createTextNode(cssData));
+  return style;
+}
+
+export {
+  capitalize,
+  fancyConsoleLog,
+  getElementTextContent,
+  getFirstElementByClassname,
+  getMetaTag,
+  icaseEqual,
+  icaseIncludes,
+  loadCss,
+  setMetaContent,
+};

src/js/integrations.js

@@ -2,10 +2,9 @@ import IntegrationsService from "./integrations/IntegrationsService";
 import StepListSection from "./integrations/StepListSection";
 import SidebarSection from "./integrations/SidebarSection";
 import { fancyConsoleLog } from "./common";
+import { loadCss } from "./common";
 
-const style = document.createElement("style");
-document.getElementsByTagName("head")[0].appendChild(style);
-style.appendChild(document.createTextNode(require("../css/integrations.css")));
+loadCss(require("../css/integrations.css"));
 
 const url = new URL(document.location.href);
 const platformFilter = url.searchParams.get("platform");