DEV: Move `Discourse.getURL` and related functions to a module (#9966)

* DEV: Move `Discourse.getURL` and related functions to a module

* DEV: Remove `Discourse.getURL` and `Discourse.getURLWithCDN`

* FIX: `get-url` is required for server side code

* DEV: Deprecate `BaseUri` too.

app/assets/javascripts/admin/components/resumable-upload.js

@@ -1,3 +1,4 @@
+import getURL from "discourse-common/lib/get-url";
 import I18n from "I18n";
 import { later, schedule } from "@ember/runloop";
 import Component from "@ember/component";
@@ -31,7 +32,7 @@ export default Component.extend({
   @on("init")
   _initialize() {
     this.resumable = new Resumable({
-      target: Discourse.getURL(this.target),
+      target: getURL(this.target),
       maxFiles: 1, // only 1 file at a time
       headers: {
         "X-CSRF-Token": document.querySelector("meta[name='csrf-token']")

app/assets/javascripts/admin/controllers/admin-dashboard-general.js

@@ -8,6 +8,7 @@ import AdminDashboard from "admin/models/admin-dashboard";
 import Report from "admin/models/report";
 import PeriodComputationMixin from "admin/mixins/period-computation";
 import { computed } from "@ember/object";
+import getURL from "discourse-common/lib/get-url";
 
 function staticReport(reportType) {
   return computed("reports.[]", function() {
@@ -20,7 +21,6 @@ export default Controller.extend(PeriodComputationMixin, {
   dashboardFetchedAt: null,
   exceptionController: inject("exception"),
   logSearchQueriesEnabled: setting("log_search_queries"),
-  basePath: Discourse.BaseUri,
 
   @discourseComputed("siteSettings.dashboard_general_tab_activity_metrics")
   activityMetrics(metrics) {
@@ -107,7 +107,7 @@ export default Controller.extend(PeriodComputationMixin, {
   @discourseComputed
   trendingSearchDisabledLabel() {
     return I18n.t("admin.dashboard.reports.trending_search.disabled", {
-      basePath: Discourse.BaseUri
+      basePath: getURL("/")
     });
   },
 
@@ -150,6 +150,6 @@ export default Controller.extend(PeriodComputationMixin, {
   },
 
   _reportsForPeriodURL(period) {
-    return Discourse.getURL(`/admin?period=${period}`);
+    return getURL(`/admin?period=${period}`);
   }
 });

app/assets/javascripts/admin/controllers/admin-dashboard-moderation.js

@@ -1,3 +1,4 @@
+import getURL from "discourse-common/lib/get-url";
 import discourseComputed from "discourse-common/utils/decorators";
 import Controller from "@ember/controller";
 import PeriodComputationMixin from "admin/mixins/period-computation";
@@ -45,6 +46,6 @@ export default Controller.extend(PeriodComputationMixin, {
   },
 
   _reportsForPeriodURL(period) {
-    return Discourse.getURL(`/admin/dashboard/moderation?period=${period}`);
+    return getURL(`/admin/dashboard/moderation?period=${period}`);
   }
 });

app/assets/javascripts/admin/controllers/admin-web-hooks-show.js

@@ -6,6 +6,7 @@ import Controller, { inject as controller } from "@ember/controller";
 import { popupAjaxError } from "discourse/lib/ajax-error";
 import { extractDomainFromUrl } from "discourse/lib/utilities";
 import EmberObject from "@ember/object";
+import { isAbsoluteURL } from "discourse-common/lib/get-url";
 
 export default Controller.extend({
   adminWebHooks: controller(),
@@ -109,7 +110,7 @@ export default Controller.extend({
         domain === "localhost" ||
         domain.match(/192\.168\.\d+\.\d+/) ||
         domain.match(/127\.\d+\.\d+\.\d+/) ||
-        url.startsWith(Discourse.BaseUrl)
+        isAbsoluteURL(url)
       ) {
         return bootbox.confirm(
           I18n.t("admin.web_hooks.warn_local_payload_url"),

app/assets/javascripts/admin/models/admin-user.js

@@ -1,3 +1,4 @@
+import getURL from "discourse-common/lib/get-url";
 import I18n from "I18n";
 import discourseComputed from "discourse-common/utils/decorators";
 import { filter, or, gt, lt, not } from "@ember/object/computed";
@@ -43,7 +44,7 @@ const AdminUser = User.extend({
 
   @discourseComputed
   bounceLink() {
-    return Discourse.getURL("/admin/email/bounced");
+    return getURL("/admin/email/bounced");
   },
 
   canResetBounceScore: gt("bounce_score", 0),
@@ -306,7 +307,7 @@ const AdminUser = User.extend({
       type: "POST",
       data: { username_or_email: this.username }
     })
-      .then(() => (document.location = Discourse.getURL("/")))
+      .then(() => (document.location = getURL("/")))
       .catch(e => {
         if (e.status === 404) {
           bootbox.alert(I18n.t("admin.impersonate.not_found"));
@@ -395,11 +396,11 @@ const AdminUser = User.extend({
         .then(function(data) {
           if (data.success) {
             if (data.username) {
-              document.location = Discourse.getURL(
+              document.location = getURL(
                 `/admin/users/${user.get("id")}/${data.username}`
               );
             } else {
-              document.location = Discourse.getURL("/admin/users/list/active");
+              document.location = getURL("/admin/users/list/active");
             }
           } else {
             bootbox.alert(I18n.t("admin.user.anonymize_failed"));
@@ -456,7 +457,7 @@ const AdminUser = User.extend({
             if (/^\/admin\/users\/list\//.test(location)) {
               document.location = location;
             } else {
-              document.location = Discourse.getURL("/admin/users/list/active");
+              document.location = getURL("/admin/users/list/active");
             }
           } else {
             bootbox.alert(I18n.t("admin.user.delete_failed"));

app/assets/javascripts/admin/models/backup.js

@@ -1,3 +1,4 @@
+import getURL from "discourse-common/lib/get-url";
 import I18n from "I18n";
 import { ajax } from "discourse/lib/ajax";
 import { extractError } from "discourse/lib/ajax-error";
@@ -66,7 +67,7 @@ Backup.reopenClass({
         bootbox.alert(result.message);
       } else {
         // redirect to homepage (session might be lost)
-        window.location = Discourse.getURL("/");
+        window.location = getURL("/");
       }
     });
   }

app/assets/javascripts/admin/models/email-log.js

@@ -1,3 +1,4 @@
+import getURL from "discourse-common/lib/get-url";
 import { ajax } from "discourse/lib/ajax";
 import AdminUser from "admin/models/admin-user";
 import EmberObject from "@ember/object";
@@ -13,7 +14,7 @@ EmailLog.reopenClass({
     }
 
     if (attrs.post_url) {
-      attrs.post_url = Discourse.getURL(attrs.post_url);
+      attrs.post_url = getURL(attrs.post_url);
     }
 
     return this._super(attrs);

app/assets/javascripts/admin/models/report.js

@@ -1,3 +1,4 @@
+import getURL from "discourse-common/lib/get-url";
 import I18n from "I18n";
 import discourseComputed from "discourse-common/utils/decorators";
 import { makeArray } from "discourse-common/lib/helpers";
@@ -37,7 +38,7 @@ const Report = EmberObject.extend({
       .locale("en")
       .format("YYYY-MM-DD");
 
-    return Discourse.getURL(
+    return getURL(
       `/admin/reports/${type}?start_date=${start_date}&end_date=${end_date}`
     );
   },
@@ -335,7 +336,7 @@ const Report = EmberObject.extend({
         avatar_template: row[properties.avatar]
       });
 
-      const href = Discourse.getURL(`/admin/users/${userId}/${username}`);
+      const href = getURL(`/admin/users/${userId}/${username}`);
 
       const avatarImg = renderAvatar(user, {
         imageSize: "tiny",
@@ -356,7 +357,7 @@ const Report = EmberObject.extend({
 
     const formatedValue = () => {
       const topicId = row[properties.id];
-      const href = Discourse.getURL(`/t/-/${topicId}`);
+      const href = getURL(`/t/-/${topicId}`);
       return `<a href='${href}'>${escapeExpression(topicTitle)}</a>`;
     };
 
@@ -370,7 +371,7 @@ const Report = EmberObject.extend({
     const postTitle = row[properties.truncated_raw];
     const postNumber = row[properties.number];
     const topicId = row[properties.topic_id];
-    const href = Discourse.getURL(`/t/-/${topicId}/${postNumber}`);
+    const href = getURL(`/t/-/${topicId}/${postNumber}`);
 
     return {
       property: properties.title,
@@ -434,7 +435,7 @@ const Report = EmberObject.extend({
 
   _linkLabel(properties, row) {
     const property = properties[0];
-    const value = Discourse.getURL(row[property]);
+    const value = getURL(row[property]);
     const formatedValue = (href, anchor) => {
       return `<a href="${escapeExpression(href)}">${escapeExpression(
         anchor

app/assets/javascripts/admin/routes/admin-backups.js

@@ -1,3 +1,4 @@
+import getURL from "discourse-common/lib/get-url";
 import I18n from "I18n";
 import EmberObject from "@ember/object";
 import DiscourseRoute from "discourse/routes/discourse";
@@ -40,7 +41,7 @@ export default DiscourseRoute.extend({
         );
         if (log.operation === "restore") {
           // redirect to homepage when the restore is done (session might be lost)
-          window.location = Discourse.getURL("/");
+          window.location = getURL("/");
         }
       } else {
         this.controllerFor("adminBackupsLogs")

app/assets/javascripts/admin/templates/dashboard_general.hbs

@@ -147,7 +147,7 @@
           filters=trendingSearchFilters
           isEnabled=logSearchQueriesEnabled
           disabledLabel=trendingSearchDisabledLabel}}
-        {{html-safe (i18n "admin.dashboard.reports.trending_search.more" basePath=basePath)}}
+        {{html-safe (i18n "admin.dashboard.reports.trending_search.more" basePath=(get-url "/"))}}
       </div>
     {{/if}}
   </div>

app/assets/javascripts/discourse-common/addon/lib/get-url.js

@@ -1,4 +1,5 @@
-let baseUri;
+let cdn, baseUrl, baseUri;
+let S3BaseUrl, S3CDN;
 
 export default function getURL(url) {
   if (!url) return url;
@@ -17,3 +18,42 @@ export default function getURL(url) {
 
   return baseUri + url;
 }
+
+export function getURLWithCDN(url) {
+  url = getURL(url);
+  // only relative urls
+  if (cdn && /^\/[^\/]/.test(url)) {
+    url = cdn + url;
+  } else if (S3CDN) {
+    url = url.replace(S3BaseUrl, S3CDN);
+  }
+  return url;
+}
+
+export function getAbsoluteURL(path) {
+  return baseUrl + path;
+}
+
+export function isAbsoluteURL(url) {
+  return url.startsWith(baseUrl);
+}
+
+export function withoutPrefix(path) {
+  const rootURL = (!baseUri ? "/" : baseUri).replace(/\/$/, "");
+  return path.replace(rootURL, "");
+}
+
+export function setPrefix(configBaseUri) {
+  baseUri = configBaseUri;
+}
+
+export function setupURL(configCdn, configBaseUrl, configBaseUri) {
+  cdn = configCdn;
+  baseUrl = configBaseUrl;
+  baseUri = configBaseUri;
+}
+
+export function setupS3CDN(configS3BaseUrl, configS3CDN) {
+  S3BaseUrl = configS3BaseUrl;
+  S3CDN = configS3CDN;
+}

app/assets/javascripts/discourse/app/adapters/topic-list.js

@@ -1,10 +1,11 @@
+import getURL from "discourse-common/lib/get-url";
 import { ajax } from "discourse/lib/ajax";
 import RestAdapter from "discourse/adapters/rest";
 import PreloadStore from "discourse/lib/preload-store";
 
 export function finderFor(filter, params) {
   return function() {
-    let url = Discourse.getURL("/") + filter + ".json";
+    let url = getURL("/") + filter + ".json";
 
     if (params) {
       const keys = Object.keys(params),

app/assets/javascripts/discourse/app/app.js

@@ -4,6 +4,8 @@ import { computed } from "@ember/object";
 import { buildResolver } from "discourse-common/resolver";
 import { bind } from "@ember/runloop";
 import discourseComputed, { observes } from "discourse-common/utils/decorators";
+import { default as getURL, getURLWithCDN } from "discourse-common/lib/get-url";
+import deprecated from "discourse-common/lib/deprecated";
 
 const _pluginCallbacks = [];
 
@@ -42,26 +44,19 @@ const Discourse = Application.extend({
   },
 
   getURL(url) {
-    if (!url) return url;
-
-    // if it's a non relative URL, return it.
-    if (url !== "/" && !/^\/[^\/]/.test(url)) return url;
-
-    if (url[0] !== "/") url = "/" + url;
-    if (url.startsWith(this.BaseUri)) return url;
-
-    return this.BaseUri + url;
+    deprecated(
+      "Import `getURL` from `discourse-common/lib/get-url` instead of `Discourse.getURL`",
+      { since: "2.5", dropFrom: "2.6" }
+    );
+    return getURL(url);
   },
 
   getURLWithCDN(url) {
-    url = this.getURL(url);
-    // only relative urls
-    if (this.CDN && /^\/[^\/]/.test(url)) {
-      url = this.CDN + url;
-    } else if (this.S3CDN) {
-      url = url.replace(this.S3BaseUrl, this.S3CDN);
-    }
-    return url;
+    deprecated(
+      "Import `getURLWithCDN` from `discourse-common/lib/get-url` instead of `Discourse.getURLWithCDN`",
+      { since: "2.5", dropFrom: "2.6" }
+    );
+    return getURLWithCDN(url);
   },
 
   Resolver: buildResolver("discourse"),

app/assets/javascripts/discourse/app/components/cdn-img.js

@@ -1,3 +1,4 @@
+import { getURLWithCDN } from "discourse-common/lib/get-url";
 import discourseComputed from "discourse-common/utils/decorators";
 import Component from "@ember/component";
 import { htmlSafe } from "@ember/template";
@@ -7,7 +8,7 @@ export default Component.extend({
 
   @discourseComputed("src")
   cdnSrc(src) {
-    return Discourse.getURLWithCDN(src);
+    return getURLWithCDN(src);
   },
 
   @discourseComputed("width", "height")

app/assets/javascripts/discourse/app/components/composer-editor.js

@@ -1,3 +1,4 @@
+import getURL from "discourse-common/lib/get-url";
 import I18n from "I18n";
 import { debounce, later, next, schedule, throttle } from "@ember/runloop";
 import Component from "@ember/component";
@@ -650,9 +651,7 @@ export default Component.extend({
     const $element = $(this.element);
 
     $element.fileupload({
-      url: Discourse.getURL(
-        `/uploads.json?client_id=${this.messageBus.clientId}`
-      ),
+      url: getURL(`/uploads.json?client_id=${this.messageBus.clientId}`),
       dataType: "json",
       pasteZone: $element
     });

app/assets/javascripts/discourse/app/components/discourse-tag-bound.js

@@ -1,3 +1,4 @@
+import getURL from "discourse-common/lib/get-url";
 import discourseComputed from "discourse-common/utils/decorators";
 import Component from "@ember/component";
 
@@ -13,6 +14,6 @@ export default Component.extend({
 
   @discourseComputed("tagRecord.id")
   href(tagRecordId) {
-    return Discourse.getURL("/tag/" + tagRecordId);
+    return getURL("/tag/" + tagRecordId);
   }
 });

app/assets/javascripts/discourse/app/components/edit-category-general.js

@@ -1,3 +1,4 @@
+import getURL from "discourse-common/lib/get-url";
 import discourseComputed from "discourse-common/utils/decorators";
 import { isEmpty } from "@ember/utils";
 import { not } from "@ember/object/computed";
@@ -27,10 +28,10 @@ export default buildCategoryPanel("general", {
   },
 
   canSelectParentCategory: not("category.isUncategorizedCategory"),
-  uncategorizedSiteSettingLink: Discourse.getURL(
+  uncategorizedSiteSettingLink: getURL(
     "/admin/site_settings/category/all_results?filter=allow_uncategorized_topics"
   ),
-  customizeTextContentLink: Discourse.getURL(
+  customizeTextContentLink: getURL(
     "/admin/customize/site_texts?q=uncategorized"
   ),
 

app/assets/javascripts/discourse/app/components/global-notice.js

@@ -1,3 +1,4 @@
+import getURL from "discourse-common/lib/get-url";
 import I18n from "I18n";
 import { bind, cancel } from "@ember/runloop";
 import Component from "@ember/component";
@@ -105,7 +106,7 @@ export default Component.extend({
 
       if (this.site.wizard_required) {
         const requiredText = I18n.t("wizard_required", {
-          url: Discourse.getURL("/wizard")
+          url: getURL("/wizard")
         });
         notices.push(Notice.create({ text: requiredText, id: "alert-wizard" }));
       }

app/assets/javascripts/discourse/app/components/google-search.js

@@ -1,3 +1,4 @@
+import getURL from "discourse-common/lib/get-url";
 import discourseComputed from "discourse-common/utils/decorators";
 import { alias } from "@ember/object/computed";
 import Component from "@ember/component";
@@ -10,6 +11,6 @@ export default Component.extend({
 
   @discourseComputed
   siteUrl() {
-    return `${location.protocol}//${location.host}${Discourse.getURL("/")}`;
+    return `${location.protocol}//${location.host}${getURL("/")}`;
   }
 });

app/assets/javascripts/discourse/app/components/group-flair-inputs.js

@@ -1,3 +1,4 @@
+import getURL from "discourse-common/lib/get-url";
 import I18n from "I18n";
 import discourseComputed from "discourse-common/utils/decorators";
 import { debounce } from "@ember/runloop";
@@ -14,7 +15,7 @@ export default Component.extend({
 
   @discourseComputed
   demoAvatarUrl() {
-    return Discourse.getURL("/images/avatar.png");
+    return getURL("/images/avatar.png");
   },
 
   @discourseComputed("model.flair_type")
@@ -105,7 +106,7 @@ export default Component.extend({
   @action
   setFlairImage(upload) {
     this.model.setProperties({
-      flair_url: Discourse.getURL(upload.url),
+      flair_url: getURL(upload.url),
       flair_upload_id: upload.id
     });
   },

app/assets/javascripts/discourse/app/components/group-post.js

@@ -1,9 +1,10 @@
+import getURL from "discourse-common/lib/get-url";
 import discourseComputed from "discourse-common/utils/decorators";
 import Component from "@ember/component";
 
 export default Component.extend({
   @discourseComputed("post.url")
   postUrl(url) {
-    return Discourse.getURL(url);
+    return getURL(url);
   }
 });

app/assets/javascripts/discourse/app/components/image-uploader.js

@@ -1,3 +1,4 @@
+import { getURLWithCDN } from "discourse-common/lib/get-url";
 import discourseComputed from "discourse-common/utils/decorators";
 import { isEmpty } from "@ember/utils";
 import { next } from "@ember/runloop";
@@ -43,7 +44,7 @@ export default Component.extend(UploadMixin, {
       return "".htmlSafe();
     }
 
-    return Discourse.getURLWithCDN(url);
+    return getURLWithCDN(url);
   },
 
   @discourseComputed("imageCDNURL")

app/assets/javascripts/discourse/app/components/related-messages.js

@@ -1,3 +1,4 @@
+import getURL from "discourse-common/lib/get-url";
 import discourseComputed from "discourse-common/utils/decorators";
 import Component from "@ember/component";
 
@@ -23,7 +24,7 @@ export default Component.extend({
 
   @discourseComputed
   searchLink() {
-    return Discourse.getURL(
+    return getURL(
       `/search?expanded=true&q=%40${this.targetUser.username}%20in%3Apersonal-direct`
     );
   },

app/assets/javascripts/discourse/app/components/suggested-topics.js

@@ -1,3 +1,4 @@
+import getURL from "discourse-common/lib/get-url";
 import I18n from "I18n";
 import discourseComputed from "discourse-common/utils/decorators";
 import { computed, get } from "@ember/object";
@@ -25,7 +26,7 @@ export default Component.extend({
     }
 
     const opts = {
-      latestLink: `<a href="${Discourse.getURL("/latest")}">${I18n.t(
+      latestLink: `<a href="${getURL("/latest")}">${I18n.t(
         "topic.view_latest_topics"
       )}</a>`
     };
@@ -43,7 +44,7 @@ export default Component.extend({
     } else {
       opts.catLink =
         '<a href="' +
-        Discourse.getURL("/categories") +
+        getURL("/categories") +
         '">' +
         I18n.t("topic.browse_all_categories") +
         "</a>";

app/assets/javascripts/discourse/app/components/user-card-contents.js

@@ -1,3 +1,4 @@
+import { getURLWithCDN } from "discourse-common/lib/get-url";
 import I18n from "I18n";
 import { isEmpty } from "@ember/utils";
 import { alias, gte, and, gt, not, or } from "@ember/object/computed";
@@ -153,7 +154,7 @@ export default Component.extend(CardContentsBase, CanCheckEmails, CleansUp, {
     }
 
     const url = this.get("user.card_background_upload_url");
-    const bg = isEmpty(url) ? "" : `url(${Discourse.getURLWithCDN(url)})`;
+    const bg = isEmpty(url) ? "" : `url(${getURLWithCDN(url)})`;
     thisElem.style.backgroundImage = bg;
   },
 

app/assets/javascripts/discourse/app/controllers/bookmark.js

@@ -270,11 +270,6 @@ export default Controller.extend(ModalFunctionality, {
     return this.nextMonth().format(I18n.t("dates.long_no_year"));
   },
 
-  @discourseComputed()
-  basePath() {
-    return Discourse.BaseUri;
-  },
-
   @discourseComputed("userTimezone")
   userHasTimezoneSet(userTimezone) {
     return !_.isEmpty(userTimezone);

app/assets/javascripts/discourse/app/controllers/composer.js

@@ -1,3 +1,4 @@
+import getURL from "discourse-common/lib/get-url";
 import I18n from "I18n";
 import { isEmpty } from "@ember/utils";
 import { and, or, alias, reads } from "@ember/object/computed";
@@ -561,7 +562,7 @@ export default Controller.extend({
       ) {
         groups.forEach(group => {
           let body;
-          const groupLink = Discourse.getURL(`/g/${group.name}/members`);
+          const groupLink = getURL(`/g/${group.name}/members`);
 
           if (group.max_mentions < group.user_count) {
             body = I18n.t("composer.group_mentioned_limit", {

app/assets/javascripts/discourse/app/controllers/create-account.js

@@ -1,3 +1,4 @@
+import getURL from "discourse-common/lib/get-url";
 import I18n from "I18n";
 import { A } from "@ember/array";
 import { isEmpty } from "@ember/utils";
@@ -86,10 +87,9 @@ export default Controller.extend(
     @discourseComputed
     disclaimerHtml() {
       return I18n.t("create_account.disclaimer", {
-        tos_link: this.get("siteSettings.tos_url") || Discourse.getURL("/tos"),
+        tos_link: this.get("siteSettings.tos_url") || getURL("/tos"),
         privacy_link:
-          this.get("siteSettings.privacy_policy_url") ||
-          Discourse.getURL("/privacy")
+          this.get("siteSettings.privacy_policy_url") || getURL("/privacy")
       });
     },
 

app/assets/javascripts/discourse/app/controllers/email-login.js

@@ -1,3 +1,4 @@
+import getURL from "discourse-common/lib/get-url";
 import discourseComputed from "discourse-common/utils/decorators";
 import Controller from "@ember/controller";
 import { SECOND_FACTOR_METHODS } from "discourse/models/user";
@@ -7,7 +8,7 @@ import { popupAjaxError } from "discourse/lib/ajax-error";
 import { getWebauthnCredential } from "discourse/lib/webauthn";
 
 export default Controller.extend({
-  lockImageUrl: Discourse.getURL("/images/lock.svg"),
+  lockImageUrl: getURL("/images/lock.svg"),
 
   @discourseComputed("model")
   secondFactorRequired(model) {

app/assets/javascripts/discourse/app/controllers/forgot-password.js

@@ -6,6 +6,7 @@ import { ajax } from "discourse/lib/ajax";
 import ModalFunctionality from "discourse/mixins/modal-functionality";
 import { escapeExpression } from "discourse/lib/utilities";
 import { extractError } from "discourse/lib/ajax-error";
+import getURL from "discourse-common/lib/get-url";
 
 export default Controller.extend(ModalFunctionality, {
   offerHelp: null,
@@ -30,7 +31,7 @@ export default Controller.extend(ModalFunctionality, {
     help() {
       this.setProperties({
         offerHelp: I18n.t("forgot_password.help", {
-          basePath: Discourse.BaseUri
+          basePath: getURL("/")
         }),
         helpSeen: true
       });

app/assets/javascripts/discourse/app/controllers/login.js

@@ -1,3 +1,4 @@
+import getURL from "discourse-common/lib/get-url";
 import I18n from "I18n";
 import discourseComputed from "discourse-common/utils/decorators";
 import { isEmpty } from "@ember/utils";
@@ -372,8 +373,8 @@ export default Controller.extend(ModalFunctionality, {
         // redirect client to the original URL
         $.removeCookie("destination_url");
         window.location.href = destinationUrl;
-      } else if (window.location.pathname === Discourse.getURL("/login")) {
-        window.location = Discourse.getURL("/");
+      } else if (window.location.pathname === getURL("/login")) {
+        window.location = getURL("/");
       } else {
         window.location.reload();
       }

app/assets/javascripts/discourse/app/controllers/password-reset.js

@@ -1,3 +1,4 @@
+import getURL from "discourse-common/lib/get-url";
 import I18n from "I18n";
 import { alias, or, readOnly } from "@ember/object/computed";
 import Controller from "@ember/controller";
@@ -41,10 +42,10 @@ export default Controller.extend(PasswordValidation, {
 
   @discourseComputed("redirectTo")
   redirectHref(redirectTo) {
-    return Discourse.getURL(redirectTo || "/");
+    return getURL(redirectTo || "/");
   },
 
-  lockImageUrl: Discourse.getURL("/images/lock.svg"),
+  lockImageUrl: getURL("/images/lock.svg"),
 
   actions: {
     submit() {

app/assets/javascripts/discourse/app/controllers/preferences/account.js

@@ -1,3 +1,4 @@
+import getURL from "discourse-common/lib/get-url";
 import I18n from "I18n";
 import { not, or, gt } from "@ember/object/computed";
 import Controller from "@ember/controller";
@@ -195,7 +196,7 @@ export default Controller.extend(CanCheckEmails, {
                 () => {
                   bootbox.alert(
                     I18n.t("user.deleted_yourself"),
-                    () => (window.location = Discourse.getURL("/"))
+                    () => (window.location = getURL("/"))
                   );
                 },
                 () => {

app/assets/javascripts/discourse/app/helpers/category-link.js

@@ -1,3 +1,4 @@
+import getURL from "discourse-common/lib/get-url";
 import I18n from "I18n";
 import { get } from "@ember/object";
 import { registerUnbound } from "discourse-common/lib/helpers";
@@ -104,9 +105,7 @@ function defaultCategoryLinkRenderer(category, opts) {
   let restricted = get(category, "read_restricted");
   let url = opts.url
     ? opts.url
-    : Discourse.getURL(
-        `/c/${Category.slugFor(category)}/${get(category, "id")}`
-      );
+    : getURL(`/c/${Category.slugFor(category)}/${get(category, "id")}`);
   let href = opts.link === false ? "" : url;
   let tagName = opts.link === false || opts.link === "false" ? "span" : "a";
   let extraClasses = opts.extraClasses ? " " + opts.extraClasses : "";

app/assets/javascripts/discourse/app/initializers/message-bus.js

@@ -1,3 +1,4 @@
+import getURL from "discourse-common/lib/get-url";
 // Initialize the message bus to receive messages.
 import userPresent from "discourse/lib/user-presence";
 import { handleLogoff } from "discourse/lib/ajax";
@@ -84,7 +85,7 @@ export default {
         return ajax(opts);
       };
 
-      messageBus.baseUrl = Discourse.getURL("/");
+      messageBus.baseUrl = getURL("/");
     }
 
     if (user) {

app/assets/javascripts/discourse/app/initializers/register-service-worker.js

@@ -1,3 +1,6 @@
+import { isAbsoluteURL } from "discourse-common/lib/get-url";
+import getURL from "discourse-common/lib/get-url";
+
 export default {
   name: "register-service-worker",
 
@@ -30,7 +33,7 @@ export default {
         });
 
         navigator.serviceWorker
-          .register(`${Discourse.BaseUri}/${Discourse.ServiceWorkerURL}`)
+          .register(`${getURL(Discourse.ServiceWorkerURL)}`)
           .catch(error => {
             // eslint-disable-next-line no-console
             console.info(`Failed to register Service Worker: ${error}`);
@@ -46,7 +49,7 @@ export default {
   },
 
   unregister(registration) {
-    if (registration.scope.startsWith(Discourse.BaseUrl)) {
+    if (isAbsoluteURL(registration.scope)) {
       registration.unregister();
     }
   }

app/assets/javascripts/discourse/app/lib/ajax.js

@@ -1,3 +1,4 @@
+import getURL from "discourse-common/lib/get-url";
 import I18n from "I18n";
 import { run } from "@ember/runloop";
 import userPresent from "discourse/lib/user-presence";
@@ -159,7 +160,7 @@ export function ajax() {
       args.cache = true; // Disable JQuery cache busting param, which was created to deal with IE8
     }
 
-    ajaxObj = $.ajax(Discourse.getURL(url), args);
+    ajaxObj = $.ajax(getURL(url), args);
   }
 
   let promise;
@@ -169,7 +170,7 @@ export function ajax() {
   if (
     args.type &&
     args.type.toUpperCase() !== "GET" &&
-    url !== Discourse.getURL("/clicks/track") &&
+    url !== getURL("/clicks/track") &&
     !Session.currentProp("csrfToken")
   ) {
     promise = new Promise((resolve, reject) => {

app/assets/javascripts/discourse/app/lib/category-tag-search.js

@@ -1,3 +1,4 @@
+import getURL from "discourse-common/lib/get-url";
 import discourseDebounce from "discourse/lib/debounce";
 import { CANCELLED_STATUS } from "discourse/lib/autocomplete";
 import Category from "discourse/models/category";
@@ -27,7 +28,7 @@ function searchTags(term, categories, limit) {
     );
 
     const debouncedSearch = discourseDebounce((q, cats, resultFunc) => {
-      oldSearch = $.ajax(Discourse.getURL("/tags/filter/search"), {
+      oldSearch = $.ajax(getURL("/tags/filter/search"), {
         type: "GET",
         cache: true,
         data: { limit: limit, q }

app/assets/javascripts/discourse/app/lib/click-track.js

@@ -1,3 +1,4 @@
+import getURL from "discourse-common/lib/get-url";
 import I18n from "I18n";
 import { later } from "@ember/runloop";
 import { ajax } from "discourse/lib/ajax";
@@ -106,9 +107,9 @@ export default {
         data.append("url", href);
         data.append("post_id", postId);
         data.append("topic_id", topicId);
-        navigator.sendBeacon(Discourse.getURL("/clicks/track"), data);
+        navigator.sendBeacon(getURL("/clicks/track"), data);
       } else {
-        trackPromise = ajax(Discourse.getURL("/clicks/track"), {
+        trackPromise = ajax(getURL("/clicks/track"), {
           type: "POST",
           data: {
             url: href,

app/assets/javascripts/discourse/app/lib/computed.js

@@ -1,3 +1,4 @@
+import getURL from "discourse-common/lib/get-url";
 import I18n from "I18n";
 import { computed } from "@ember/object";
 import { htmlSafe as htmlSafeTemplateHelper } from "@ember/template";
@@ -126,7 +127,7 @@ export function fmt(...args) {
 export function url(...args) {
   const format = args.pop();
   return computed(...args, function() {
-    return Discourse.getURL(addonFmt(format, ...args.map(a => this.get(a))));
+    return getURL(addonFmt(format, ...args.map(a => this.get(a))));
   });
 }
 

app/assets/javascripts/discourse/app/lib/discourse-location.js

@@ -1,6 +1,7 @@
 import EmberObject from "@ember/object";
 import { defaultHomepage } from "discourse/lib/utilities";
 import { guidFor } from "@ember/object/internals";
+import { withoutPrefix } from "discourse-common/lib/get-url";
 let popstateFired = false;
 const supportsHistoryState = window.history && "state" in window.history;
 const popstateCallbacks = [];
@@ -62,10 +63,7 @@ const DiscourseLocation = EmberObject.extend({
     @method getURL
   */
   getURL() {
-    let url = this.location.pathname;
-
-    url = url.replace(new RegExp(`^${Discourse.BaseUri}`), "");
-
+    let url = withoutPrefix(this.location.pathname);
     const search = this.location.search || "";
     url += search;
     return url;

app/assets/javascripts/discourse/app/lib/keyboard-shortcuts.js

@@ -471,9 +471,7 @@ export default {
   },
 
   _bindToPath(path, key) {
-    this.keyTrapper.bind(key, () =>
-      DiscourseURL.routeTo(Discourse.BaseUri + path)
-    );
+    this.keyTrapper.bind(key, () => DiscourseURL.routeTo(path));
   },
 
   _bindToClick(selector, binding) {

app/assets/javascripts/discourse/app/lib/link-mentions.js

@@ -1,3 +1,4 @@
+import getURL from "discourse-common/lib/get-url";
 import { schedule } from "@ember/runloop";
 import { ajax } from "discourse/lib/ajax";
 import { userPath } from "discourse/lib/url";
@@ -15,7 +16,7 @@ function replaceSpan($e, username, opts) {
       extraClass = "notify";
     }
     $e.replaceWith(
-      `<a href='${Discourse.getURL("/g/") +
+      `<a href='${getURL("/g/") +
         username}' class='mention-group ${extraClass}' ${extra}>@${username}</a>`
     );
   } else {

app/assets/javascripts/discourse/app/lib/load-script.js

@@ -1,3 +1,4 @@
+import { default as getURL, getURLWithCDN } from "discourse-common/lib/get-url";
 import { run } from "@ember/runloop";
 import { ajax } from "discourse/lib/ajax";
 import { Promise } from "rsvp";
@@ -51,9 +52,7 @@ export default function loadScript(url, opts) {
 
   // Scripts should always load from CDN
   // CSS is type text, to accept it from a CDN we would need to handle CORS
-  const fullUrl = opts.css
-    ? Discourse.getURL(url)
-    : Discourse.getURLWithCDN(url);
+  const fullUrl = opts.css ? getURL(url) : getURLWithCDN(url);
 
   $("script").each((i, tag) => {
     const src = tag.getAttribute("src");

app/assets/javascripts/discourse/app/lib/logout.js

@@ -1,3 +1,4 @@
+import getURL from "discourse-common/lib/get-url";
 import { isEmpty } from "@ember/utils";
 import { findAll } from "discourse/models/login-method";
 
@@ -23,9 +24,9 @@ export default function logout(siteSettings, keyValueStore) {
   if (siteSettings.login_required && (sso || oneAuthenticator)) {
     // In this situation visiting most URLs will start the auth process again
     // Go to the `/login` page to avoid an immediate redirect
-    window.location.href = Discourse.getURL("/login");
+    window.location.href = getURL("/login");
     return;
   }
 
-  window.location.href = Discourse.getURL("/");
+  window.location.href = getURL("/");
 }

app/assets/javascripts/discourse/app/lib/page-tracker.js

@@ -1,3 +1,4 @@
+import getURL from "discourse-common/lib/get-url";
 import { next } from "@ember/runloop";
 let _started = false;
 let cache = {};
@@ -28,7 +29,7 @@ export function startPageTracking(router, appEvents) {
       transition.urlMethod === "replace" && transition.queryParamsOnly;
 
     router.send("refreshTitle");
-    const url = Discourse.getURL(router.get("url"));
+    const url = getURL(router.get("url"));
 
     // Refreshing the title is debounced, so we need to trigger this in the
     // next runloop to have the correct title.

app/assets/javascripts/discourse/app/lib/render-tag.js

@@ -1,3 +1,4 @@
+import getURL from "discourse-common/lib/get-url";
 import User from "discourse/models/user";
 import { escapeExpression } from "discourse/lib/utilities";
 
@@ -24,7 +25,7 @@ export function defaultRenderTag(tag, params) {
       path = `/tag/${tag}`;
     }
   }
-  const href = path ? ` href='${Discourse.getURL(path)}' ` : "";
+  const href = path ? ` href='${getURL(path)}' ` : "";
 
   if (Discourse.SiteSettings.tag_style || params.style) {
     classes.push(params.style || Discourse.SiteSettings.tag_style);

app/assets/javascripts/discourse/app/lib/search.js

@@ -1,3 +1,4 @@
+import getURL from "discourse-common/lib/get-url";
 import I18n from "I18n";
 import { isEmpty } from "@ember/utils";
 import EmberObject from "@ember/object";
@@ -67,7 +68,7 @@ export function translateResults(results, opts) {
         flairBgColor,
         fullName,
         name,
-        url: Discourse.getURL(`/g/${name}`)
+        url: getURL(`/g/${name}`)
       };
     })
     .compact();
@@ -77,7 +78,7 @@ export function translateResults(results, opts) {
       const tagName = escapeExpression(tag.name);
       return EmberObject.create({
         id: tagName,
-        url: Discourse.getURL("/tag/" + tagName)
+        url: getURL("/tag/" + tagName)
       });
     })
     .compact();

app/assets/javascripts/discourse/app/lib/text.js

@@ -1,3 +1,4 @@
+import { getURLWithCDN } from "discourse-common/lib/get-url";
 import PrettyText, { buildOptions } from "pretty-text/pretty-text";
 import { performEmojiUnescape, buildEmojiUrl } from "pretty-text/emoji";
 import WhiteLister from "pretty-text/white-lister";
@@ -7,8 +8,6 @@ import { formatUsername } from "discourse/lib/utilities";
 import { Promise } from "rsvp";
 import { htmlSafe } from "@ember/template";
 
-const getURLWithCDN = url => Discourse.getURLWithCDN(url);
-
 function getOpts(opts) {
   const siteSettings = Discourse.__container__.lookup("site-settings:main"),
     site = Discourse.__container__.lookup("site:main");

app/assets/javascripts/discourse/app/lib/url.js

@@ -5,6 +5,7 @@ import offsetCalculator from "discourse/lib/offset-calculator";
 import LockOn from "discourse/lib/lock-on";
 import { defaultHomepage } from "discourse/lib/utilities";
 import User from "discourse/models/user";
+import { default as getURL, withoutPrefix } from "discourse-common/lib/get-url";
 
 const rewrites = [];
 const TOPIC_REGEXP = /\/t\/([^\/]+)\/(\d+)\/?(\d+)?/;
@@ -55,11 +56,11 @@ export function clearRewrites() {
 }
 
 export function userPath(subPath) {
-  return Discourse.getURL(subPath ? `/u/${subPath}` : "/u");
+  return getURL(subPath ? `/u/${subPath}` : "/u");
 }
 
 export function groupPath(subPath) {
-  return Discourse.getURL(subPath ? `/g/${subPath}` : "/g");
+  return getURL(subPath ? `/g/${subPath}` : "/g");
 }
 
 let _jumpScheduled = false;
@@ -210,11 +211,10 @@ const DiscourseURL = EmberObject.extend({
     }
 
     if (Discourse.get("requiresRefresh")) {
-      return redirectTo(Discourse.getURL(path));
+      return redirectTo(getURL(path));
     }
 
     const pathname = path.replace(/(https?\:)?\/\/[^\/]+/, "");
-    const baseUri = Discourse.BaseUri;
 
     if (!DiscourseURL.isInternal(path)) {
       return redirectTo(path);
@@ -241,7 +241,7 @@ const DiscourseURL = EmberObject.extend({
     path = path.replace(/(https?\:)?\/\/[^\/]+/, "");
 
     // Rewrite /my/* urls
-    let myPath = `${baseUri}/my/`;
+    let myPath = getURL("/my");
     if (path.indexOf(myPath) === 0) {
       const currentUser = User.current();
       if (currentUser) {
@@ -256,11 +256,7 @@ const DiscourseURL = EmberObject.extend({
 
     // handle prefixes
     if (path.indexOf("/") === 0) {
-      const rootURL = (baseUri === undefined ? "/" : baseUri).replace(
-        /\/$/,
-        ""
-      );
-      path = path.replace(rootURL, "");
+      path = withoutPrefix(path);
     }
 
     path = rewritePath(path);
@@ -293,7 +289,7 @@ const DiscourseURL = EmberObject.extend({
   },
 
   routeToUrl(url, opts = {}) {
-    this.routeTo(Discourse.getURL(url), opts);
+    this.routeTo(getURL(url), opts);
   },
 
   rewrite(regexp, replacement, opts) {
@@ -301,7 +297,7 @@ const DiscourseURL = EmberObject.extend({
   },
 
   redirectTo(url) {
-    window.location = Discourse.getURL(url);
+    window.location = getURL(url);
   },
 
   /**
@@ -420,10 +416,8 @@ const DiscourseURL = EmberObject.extend({
 
   // This has been extracted so it can be tested.
   origin() {
-    return (
-      window.location.origin +
-      (Discourse.BaseUri === "/" ? "" : Discourse.BaseUri)
-    );
+    let prefix = getURL("/");
+    return window.location.origin + (prefix === "/" ? "" : prefix);
   },
 
   // TODO: These container calls can be replaced eventually if we migrate this to a service

app/assets/javascripts/discourse/app/lib/utilities.js

@@ -2,6 +2,7 @@ import I18n from "I18n";
 import { escape } from "pretty-text/sanitizer";
 import toMarkdown from "discourse/lib/to-markdown";
 import Handlebars from "handlebars";
+import { default as getURL, getURLWithCDN } from "discourse-common/lib/get-url";
 
 const homepageSelector = "meta[name=discourse_current_homepage]";
 
@@ -55,18 +56,15 @@ export function getRawSize(size) {
   return size * Math.min(3, Math.max(1, Math.round(pixelRatio)));
 }
 
-const getURLWithCDN = url => Discourse.getURLWithCDN(url);
-
-export function avatarImg(options, getURL) {
-  getURL = getURL || getURLWithCDN;
-
+export function avatarImg(options, customGetURL) {
   const size = translateSize(options.size);
-  const url = avatarUrl(options.avatarTemplate, size);
+  let path = avatarUrl(options.avatarTemplate, size);
 
   // We won't render an invalid url
-  if (!url || url.length === 0) {
+  if (!path || path.length === 0) {
     return "";
   }
+  path = (customGetURL || getURLWithCDN)(path);
 
   const classes =
     "avatar" + (options.extraClasses ? " " + options.extraClasses : "");
@@ -77,19 +75,7 @@ export function avatarImg(options, getURL) {
     title = ` title='${escaped}' aria-label='${escaped}'`;
   }
 
-  return (
-    "<img alt='' width='" +
-    size +
-    "' height='" +
-    size +
-    "' src='" +
-    getURL(url) +
-    "' class='" +
-    classes +
-    "'" +
-    title +
-    ">"
-  );
+  return `<img alt='' width='${size}' height='${size}' src='${path}' class='${classes}'${title}>`;
 }
 
 export function tinyAvatar(avatarTemplate, options) {
@@ -99,7 +85,7 @@ export function tinyAvatar(avatarTemplate, options) {
 }
 
 export function postUrl(slug, topicId, postNumber) {
-  var url = Discourse.getURL("/t/");
+  var url = getURL("/t/");
   if (slug) {
     url += slug + "/";
   } else {
@@ -430,7 +416,7 @@ function reportToLogster(name, error) {
     stacktrace: error.stack
   };
 
-  Ember.$.ajax(`${Discourse.BaseUri}/logs/report_js_error`, {
+  Ember.$.ajax(getURL("/logs/report_js_error"), {
     data,
     type: "POST",
     cache: false
@@ -447,7 +433,7 @@ export function rescueThemeError(name, error, api) {
     return;
   }
 
-  const path = `${Discourse.BaseUri}/admin/customize/themes`;
+  const path = getURL(`/admin/customize/themes`);
   const message = I18n.t("themes.broken_theme_alert", {
     theme: name,
     path: `<a href="${path}">${path}</a>`

app/assets/javascripts/discourse/app/mapping-router.js

@@ -3,11 +3,9 @@ import { defaultHomepage } from "discourse/lib/utilities";
 import { rewritePath } from "discourse/lib/url";
 import Site from "discourse/models/site";
 import { isTesting } from "discourse-common/config/environment";
-
-const rootURL = Discourse.BaseUri;
+import getURL from "discourse-common/lib/get-url";
 
 const BareRouter = EmberRouter.extend({
-  rootURL,
   location: isTesting() ? "none" : "discourse-location",
 
   handleURL(url) {
@@ -136,10 +134,10 @@ export function mapRoutes() {
     }
   });
 
-  return BareRouter.extend().map(function() {
+  return BareRouter.extend({
+    rootURL: getURL("/")
+  }).map(function() {
     tree.mapRoutes(this);
     this.route("unknown", { path: "*path" });
   });
 }
-
-export default BareRouter;

app/assets/javascripts/discourse/app/models/badge.js

@@ -1,3 +1,4 @@
+import getURL from "discourse-common/lib/get-url";
 import discourseComputed from "discourse-common/utils/decorators";
 import { none } from "@ember/object/computed";
 import EmberObject from "@ember/object";
@@ -11,7 +12,7 @@ const Badge = RestModel.extend({
 
   @discourseComputed
   url() {
-    return Discourse.getURL(`/badges/${this.id}/${this.slug}`);
+    return getURL(`/badges/${this.id}/${this.slug}`);
   },
 
   updateFromJson(json) {

app/assets/javascripts/discourse/app/models/bookmark.js

@@ -1,3 +1,4 @@
+import getURL from "discourse-common/lib/get-url";
 import I18n from "I18n";
 import Category from "discourse/models/category";
 import User from "discourse/models/user";
@@ -19,7 +20,7 @@ const Bookmark = RestModel.extend({
 
   @computed
   get url() {
-    return Discourse.getURL(`/bookmarks/${this.id}`);
+    return getURL(`/bookmarks/${this.id}`);
   },
 
   destroy() {
@@ -37,7 +38,7 @@ const Bookmark = RestModel.extend({
 
   // Helper to build a Url with a post number
   urlForPostNumber(postNumber) {
-    let url = Discourse.getURL(`/t/${this.topic_id}`);
+    let url = getURL(`/t/${this.topic_id}`);
     if (postNumber > 0) {
       url += `/${postNumber}`;
     }

app/assets/javascripts/discourse/app/models/category.js

@@ -1,3 +1,4 @@
+import getURL from "discourse-common/lib/get-url";
 import discourseComputed from "discourse-common/utils/decorators";
 import { get } from "@ember/object";
 import { ajax } from "discourse/lib/ajax";
@@ -96,7 +97,7 @@ const Category = RestModel.extend({
 
   @discourseComputed("name")
   url() {
-    return Discourse.getURL(`/c/${Category.slugFor(this)}/${this.id}`);
+    return getURL(`/c/${Category.slugFor(this)}/${this.id}`);
   },
 
   @discourseComputed

app/assets/javascripts/discourse/app/models/login-method.js

@@ -1,3 +1,4 @@
+import getURL from "discourse-common/lib/get-url";
 import I18n from "I18n";
 import discourseComputed from "discourse-common/utils/decorators";
 import EmberObject from "@ember/object";
@@ -33,7 +34,7 @@ const LoginMethod = EmberObject.extend({
       return Promise.resolve();
     }
 
-    let authUrl = Discourse.getURL(`/auth/${this.name}`);
+    let authUrl = getURL(`/auth/${this.name}`);
 
     if (reconnect) {
       params["reconnect"] = true;

app/assets/javascripts/discourse/app/models/nav-item.js

@@ -1,3 +1,4 @@
+import getURL from "discourse-common/lib/get-url";
 import I18n from "I18n";
 import discourseComputed from "discourse-common/utils/decorators";
 import { emojiUnescape } from "discourse/lib/text";
@@ -105,7 +106,7 @@ NavItem.reopenClass({
   extraNavItemDescriptors: [],
 
   pathFor(filterType, context) {
-    let path = Discourse.getURL("");
+    let path = getURL("");
     let includesCategoryContext = false;
     let includesTagContext = false;
 

app/assets/javascripts/discourse/app/models/published-page.js

@@ -1,8 +1,9 @@
 import RestModel from "discourse/models/rest";
 import { computed } from "@ember/object";
+import { getAbsoluteURL } from "discourse-common/lib/get-url";
 
 export default RestModel.extend({
   url: computed("slug", function() {
-    return `${Discourse.BaseUrl}/pub/${this.slug}`;
+    return getAbsoluteURL(`/pub/${this.slug}`);
   })
 });

app/assets/javascripts/discourse/app/models/topic-details.js

@@ -3,6 +3,8 @@ import discourseComputed from "discourse-common/utils/decorators";
 import EmberObject from "@ember/object";
 import { ajax } from "discourse/lib/ajax";
 import User from "discourse/models/user";
+import getURL from "discourse-common/lib/get-url";
+
 /**
   A model representing a Topic's details that aren't always present, such as a list of participants.
   When showing topics in lists and such this information should not be required.
@@ -56,7 +58,7 @@ const TopicDetails = RestModel.extend({
     } else {
       return I18n.t(localeString, {
         username: User.currentProp("username_lower"),
-        basePath: Discourse.BaseUri
+        basePath: getURL("/")
       });
     }
   },

app/assets/javascripts/discourse/app/models/topic-list.js

@@ -1,3 +1,4 @@
+import getURL from "discourse-common/lib/get-url";
 import { notEmpty } from "@ember/object/computed";
 import EmberObject from "@ember/object";
 import { ajax } from "discourse/lib/ajax";
@@ -124,9 +125,9 @@ const TopicList = RestModel.extend({
       this.topics.filter(topic => topic_ids.indexOf(topic.id) >= 0)
     );
 
-    const url = `${Discourse.getURL("/")}${
-      this.filter
-    }.json?topic_ids=${topic_ids.join(",")}`;
+    const url = `${getURL("/")}${this.filter}.json?topic_ids=${topic_ids.join(
+      ","
+    )}`;
 
     return ajax({ url, data: this.params }).then(result => {
       let i = 0;

app/assets/javascripts/discourse/app/models/topic.js

@@ -1,3 +1,4 @@
+import getURL from "discourse-common/lib/get-url";
 import I18n from "I18n";
 import EmberObject from "@ember/object";
 import { not, notEmpty, equal, and, or } from "@ember/object/computed";
@@ -25,7 +26,7 @@ import User from "discourse/models/user";
 
 export function loadTopicView(topic, args) {
   const data = _.merge({}, args);
-  const url = `${Discourse.getURL("/t/")}${topic.id}`;
+  const url = `${getURL("/t/")}${topic.id}`;
   const jsonUrl = (data.nearPost ? `${url}/${data.nearPost}` : url) + ".json";
 
   delete data.nearPost;
@@ -259,7 +260,7 @@ const Topic = RestModel.extend({
     if (slug.trim().length === 0) {
       slug = "topic";
     }
-    return `${Discourse.getURL("/t/")}${slug}/${id}`;
+    return `${getURL("/t/")}${slug}/${id}`;
   },
 
   // Helper to build a Url with a post number
@@ -739,7 +740,7 @@ Topic.reopenClass({
 
   // Load a topic, but accepts a set of filters
   find(topicId, opts) {
-    let url = Discourse.getURL("/t/") + topicId;
+    let url = getURL("/t/") + topicId;
     if (opts.nearPost) {
       url += `/${opts.nearPost}`;
     }

app/assets/javascripts/discourse/app/models/user.js

@@ -1,3 +1,5 @@
+import { getURLWithCDN } from "discourse-common/lib/get-url";
+import getURL from "discourse-common/lib/get-url";
 import I18n from "I18n";
 import { A } from "@ember/array";
 import { isEmpty } from "@ember/utils";
@@ -109,11 +111,7 @@ const User = RestModel.extend({
     if (isEmpty(bgUrl) || !Discourse.SiteSettings.allow_profile_backgrounds) {
       return "".htmlSafe();
     }
-    return (
-      "background-image: url(" +
-      Discourse.getURLWithCDN(bgUrl) +
-      ")"
-    ).htmlSafe();
+    return ("background-image: url(" + getURLWithCDN(bgUrl) + ")").htmlSafe();
   },
 
   @discourseComputed()
@@ -183,22 +181,22 @@ const User = RestModel.extend({
   @discourseComputed()
   mutedTopicsPath() {
     return defaultHomepage() === "latest"
-      ? Discourse.getURL("/?state=muted")
-      : Discourse.getURL("/latest?state=muted");
+      ? getURL("/?state=muted")
+      : getURL("/latest?state=muted");
   },
 
   @discourseComputed()
   watchingTopicsPath() {
     return defaultHomepage() === "latest"
-      ? Discourse.getURL("/?state=watching")
-      : Discourse.getURL("/latest?state=watching");
+      ? getURL("/?state=watching")
+      : getURL("/latest?state=watching");
   },
 
   @discourseComputed()
   trackingTopicsPath() {
     return defaultHomepage() === "latest"
-      ? Discourse.getURL("/?state=tracking")
-      : Discourse.getURL("/latest?state=tracking");
+      ? getURL("/?state=tracking")
+      : getURL("/latest?state=tracking");
   },
 
   @discourseComputed("username")

app/assets/javascripts/discourse/app/pre-initializers/discourse-bootstrap.js

@@ -7,6 +7,8 @@ import {
   isTesting,
   isProduction
 } from "discourse-common/config/environment";
+import { setupURL, setupS3CDN } from "discourse-common/lib/get-url";
+import deprecated from "discourse-common/lib/deprecated";
 
 export default {
   name: "discourse-bootstrap",
@@ -35,8 +37,28 @@ export default {
     }
 
     app.CDN = setupData.cdn;
-    app.BaseUrl = setupData.baseUrl;
-    app.BaseUri = setupData.baseUri;
+
+    let baseUrl = setupData.baseUrl;
+    Object.defineProperty(app, "BaseUrl", {
+      get() {
+        deprecated(`use "get-url" helpers instead of Discourse.BaseUrl`, {
+          since: "2.5",
+          dropFrom: "2.6"
+        });
+        return baseUrl;
+      }
+    });
+    let baseUri = setupData.baseUri;
+    Object.defineProperty(app, "BaseUri", {
+      get() {
+        deprecated(`use "get-url" helpers instead of Discourse.BaseUri`, {
+          since: "2.5",
+          dropFrom: "2.6"
+        });
+        return baseUri;
+      }
+    });
+    setupURL(setupData.cdn, baseUrl, setupData.baseUri);
     setEnvironment(setupData.environment);
     app.SiteSettings = PreloadStore.get("siteSettings");
     app.ThemeSettings = PreloadStore.get("themeSettings");
@@ -69,6 +91,7 @@ export default {
     if (setupData.s3BaseUrl) {
       app.S3CDN = setupData.s3Cdn;
       app.S3BaseUrl = setupData.s3BaseUrl;
+      setupS3CDN(setupData.s3BaseUrl, setupData.s3Cdn);
     }
 
     RSVP.configure("onerror", function(e) {

app/assets/javascripts/discourse/app/routes/application.js

@@ -1,3 +1,4 @@
+import getURL from "discourse-common/lib/get-url";
 import I18n from "I18n";
 import { once } from "@ember/runloop";
 import DiscourseRoute from "discourse/routes/discourse";
@@ -46,8 +47,8 @@ const ApplicationRoute = DiscourseRoute.extend(OpenComposer, {
     _collectTitleTokens(tokens) {
       tokens.push(this.siteTitle);
       if (
-        (window.location.pathname === Discourse.getURL("/") ||
-          window.location.pathname === Discourse.getURL("/login")) &&
+        (window.location.pathname === getURL("/") ||
+          window.location.pathname === getURL("/login")) &&
         this.shortSiteDescription !== ""
       ) {
         tokens.push(this.shortSiteDescription);
@@ -250,9 +251,7 @@ const ApplicationRoute = DiscourseRoute.extend(OpenComposer, {
   handleShowLogin() {
     if (this.siteSettings.enable_sso) {
       const returnPath = encodeURIComponent(window.location.pathname);
-      window.location = Discourse.getURL(
-        "/session/sso?return_path=" + returnPath
-      );
+      window.location = getURL("/session/sso?return_path=" + returnPath);
     } else {
       this._autoLogin("login", "login-modal", () =>
         this.controllerFor("login").resetForm()
@@ -263,9 +262,7 @@ const ApplicationRoute = DiscourseRoute.extend(OpenComposer, {
   handleShowCreateAccount() {
     if (this.siteSettings.enable_sso) {
       const returnPath = encodeURIComponent(window.location.pathname);
-      window.location = Discourse.getURL(
-        "/session/sso?return_path=" + returnPath
-      );
+      window.location = getURL("/session/sso?return_path=" + returnPath);
     } else {
       this._autoLogin("createAccount", "create-account");
     }

app/assets/javascripts/discourse/app/services/logs-notice.js

@@ -1,3 +1,4 @@
+import getURL from "discourse-common/lib/get-url";
 import I18n from "I18n";
 import { isEmpty } from "@ember/utils";
 import EmberObject from "@ember/object";
@@ -42,7 +43,7 @@ const LogsNotice = EmberObject.extend({
           ),
           rate,
           limit: siteSettingLimit,
-          url: Discourse.getURL("/logs")
+          url: getURL("/logs")
         })
       );
     });

app/assets/javascripts/discourse/app/templates/modal/bookmark.hbs

@@ -96,7 +96,7 @@
         {{/tap-tile-grid}}
 
       {{else}}
-        <div class="alert alert-info">{{html-safe (i18n "bookmarks.no_timezone" basePath=basePath)}}</div>
+        <div class="alert alert-info">{{html-safe (i18n "bookmarks.no_timezone" basePath=(get-url "/"))}}</div>
       {{/if}}
     </div>
 

app/assets/javascripts/discourse/app/widgets/actions-summary.js

@@ -1,3 +1,4 @@
+import getURL from "discourse-common/lib/get-url";
 import I18n from "I18n";
 import { createWidget } from "discourse/widgets/widget";
 import { avatarFor } from "discourse/widgets/post";
@@ -48,7 +49,7 @@ createWidget("small-user-list", {
       if (postUrl) {
         description = h(
           "a",
-          { attributes: { href: Discourse.getURL(postUrl) } },
+          { attributes: { href: getURL(postUrl) } },
           description
         );
       }

app/assets/javascripts/discourse/app/widgets/default-notification-item.js

@@ -15,6 +15,7 @@ import { setTransientHeader } from "discourse/lib/ajax";
 import { userPath } from "discourse/lib/url";
 import { iconNode } from "discourse-common/lib/icon-library";
 import { ajax } from "discourse/lib/ajax";
+import getURL from "discourse-common/lib/get-url";
 
 export const DefaultNotificationItem = createWidget(
   "default-notification-item",
@@ -46,9 +47,7 @@ export const DefaultNotificationItem = createWidget(
 
         let username = data.username;
         username = username ? "?username=" + username.toLowerCase() : "";
-        return Discourse.getURL(
-          "/badges/" + badgeId + "/" + badgeSlug + username
-        );
+        return getURL("/badges/" + badgeId + "/" + badgeSlug + username);
       }
 
       const topicId = attrs.topic_id;
@@ -134,8 +133,9 @@ export const DefaultNotificationItem = createWidget(
       const id = this.attrs.id;
       setTransientHeader("Discourse-Clear-Notifications", id);
       if (document && document.cookie) {
-        let path = Discourse.BaseUri || "/";
-        document.cookie = `cn=${id}; path=${path}; expires=Fri, 31 Dec 9999 23:59:59 GMT`;
+        document.cookie = `cn=${id}; path=${getURL(
+          "/"
+        )}; expires=Fri, 31 Dec 9999 23:59:59 GMT`;
       }
       if (wantsNewWindow(e)) {
         return;

app/assets/javascripts/discourse/app/widgets/hamburger-categories.js

@@ -1,3 +1,4 @@
+import getURL from "discourse-common/lib/get-url";
 import I18n from "I18n";
 import { createWidget } from "discourse/widgets/widget";
 import { h } from "virtual-dom";
@@ -52,7 +53,7 @@ export default createWidget("hamburger-categories", {
   tagName: "ul.category-links.clearfix",
 
   html(attrs) {
-    const href = Discourse.getURL("/categories");
+    const href = getURL("/categories");
     let title = I18n.t("filters.categories.title");
     if (attrs.moreCount > 0) {
       title = I18n.t("categories.n_more", { count: attrs.moreCount });

app/assets/javascripts/discourse/app/widgets/hamburger-menu.js

@@ -1,3 +1,4 @@
+import getURL from "discourse-common/lib/get-url";
 import I18n from "I18n";
 import { later } from "@ember/runloop";
 import { createWidget, applyDecorators } from "discourse/widgets/widget";
@@ -269,7 +270,7 @@ export default createWidget("hamburger-menu", {
 
     let faqUrl = this.siteSettings.faq_url;
     if (!faqUrl || faqUrl.length === 0) {
-      faqUrl = Discourse.getURL("/faq");
+      faqUrl = getURL("/faq");
     }
 
     const prioritizeFaq =

app/assets/javascripts/discourse/app/widgets/header-topic-info.js

@@ -1,3 +1,4 @@
+import getURL from "discourse-common/lib/get-url";
 import I18n from "I18n";
 import { applyDecorators, createWidget } from "discourse/widgets/widget";
 import { h } from "virtual-dom";
@@ -27,7 +28,7 @@ createWidget("topic-header-participant", {
       url = user.get("path");
     } else {
       content = [iconNode("users")];
-      url = Discourse.getURL(`/g/${group.name}`);
+      url = getURL(`/g/${group.name}`);
       content.push(h("span", group.name));
     }
 

app/assets/javascripts/discourse/app/widgets/header.js

@@ -1,3 +1,4 @@
+import getURL from "discourse-common/lib/get-url";
 import I18n from "I18n";
 import { get } from "@ember/object";
 import { schedule } from "@ember/runloop";
@@ -217,7 +218,7 @@ createWidget("header-icons", {
       iconId: "search-button",
       action: "toggleSearchMenu",
       active: attrs.searchVisible,
-      href: Discourse.getURL("/search")
+      href: getURL("/search")
     });
 
     const icons = [search, hamburger];

app/assets/javascripts/discourse/app/widgets/home-logo.js

@@ -1,3 +1,4 @@
+import getURL from "discourse-common/lib/get-url";
 import { createWidget } from "discourse/widgets/widget";
 import { h } from "virtual-dom";
 import { iconNode } from "discourse-common/lib/icon-library";
@@ -8,7 +9,7 @@ export default createWidget("home-logo", {
   tagName: "div.title",
 
   settings: {
-    href: Discourse.getURL("/")
+    href: getURL("/")
   },
 
   href() {
@@ -44,7 +45,7 @@ export default createWidget("home-logo", {
         return h("img#site-logo.logo-small", {
           key: "logo-small",
           attributes: {
-            src: Discourse.getURL(logoSmallUrl),
+            src: getURL(logoSmallUrl),
             width: 36,
             alt: title
           }
@@ -55,12 +56,12 @@ export default createWidget("home-logo", {
     } else if (showMobileLogo) {
       return h("img#site-logo.logo-big", {
         key: "logo-mobile",
-        attributes: { src: Discourse.getURL(mobileLogoUrl), alt: title }
+        attributes: { src: getURL(mobileLogoUrl), alt: title }
       });
     } else if (logoUrl.length) {
       return h("img#site-logo.logo-big", {
         key: "logo-big",
-        attributes: { src: Discourse.getURL(logoUrl), alt: title }
+        attributes: { src: getURL(logoUrl), alt: title }
       });
     } else {
       return h("h1#site-text-logo.text-logo", { key: "logo-text" }, title);

app/assets/javascripts/discourse/app/widgets/link.js

@@ -1,3 +1,4 @@
+import getURL from "discourse-common/lib/get-url";
 import I18n from "I18n";
 import { wantsNewWindow } from "discourse/lib/intercept-click";
 import { createWidget } from "discourse/widgets/widget";
@@ -17,12 +18,12 @@ export default createWidget("link", {
         if (attrs.model) {
           params.push(attrs.model);
         }
-        return Discourse.getURL(
+        return getURL(
           router._routerMicrolib.generate.apply(router._routerMicrolib, params)
         );
       }
     } else {
-      return Discourse.getURL(attrs.href);
+      return getURL(attrs.href);
     }
   },
 

app/assets/javascripts/discourse/app/widgets/post.js

@@ -1,3 +1,4 @@
+import { default as getURL, getURLWithCDN } from "discourse-common/lib/get-url";
 import I18n from "I18n";
 import PostCooked from "discourse/widgets/post-cooked";
 import DecoratorHelper from "discourse/widgets/decorator-helper";
@@ -43,7 +44,7 @@ export function avatarImg(wanted, attrs) {
       alt: "",
       width: size,
       height: size,
-      src: Discourse.getURLWithCDN(url),
+      src: getURLWithCDN(url),
       title
     },
     className
@@ -353,7 +354,7 @@ createWidget("post-group-request", {
   },
 
   html(attrs) {
-    const href = Discourse.getURL(
+    const href = getURL(
       "/g/" + attrs.requestedGroupName + "/requests?filter=" + attrs.username
     );
 

app/assets/javascripts/discourse/app/widgets/poster-name.js

@@ -1,3 +1,4 @@
+import getURL from "discourse-common/lib/get-url";
 import I18n from "I18n";
 import { iconNode } from "discourse-common/lib/icon-library";
 import { createWidget, applyDecorators } from "discourse/widgets/widget";
@@ -19,7 +20,7 @@ createWidget("poster-name-title", {
   html(attrs) {
     let titleContents = attrs.title;
     if (attrs.primaryGroupName && attrs.titleIsGroup) {
-      const href = Discourse.getURL(`/g/${attrs.primaryGroupName}`);
+      const href = getURL(`/g/${attrs.primaryGroupName}`);
       titleContents = h(
         "a.user-group",
         {

app/assets/javascripts/discourse/app/widgets/private-message-map.js

@@ -1,3 +1,4 @@
+import getURL from "discourse-common/lib/get-url";
 import I18n from "I18n";
 import { makeArray } from "discourse-common/lib/helpers";
 import { createWidget } from "discourse/widgets/widget";
@@ -27,7 +28,7 @@ createWidget("pm-map-user-group", {
   tagName: "div.user.group",
 
   transform(attrs) {
-    return { href: Discourse.getURL(`/g/${attrs.group.name}`) };
+    return { href: getURL(`/g/${attrs.group.name}`) };
   },
 
   template: hbs`

app/assets/javascripts/discourse/app/widgets/search-menu.js

@@ -1,3 +1,4 @@
+import getURL from "discourse-common/lib/get-url";
 import { get } from "@ember/object";
 import { debounce } from "@ember/runloop";
 import { popupAjaxError } from "discourse/lib/ajax-error";
@@ -118,7 +119,7 @@ export default createWidget("search-menu", {
       url = `${url}?${params.join("&")}`;
     }
 
-    return Discourse.getURL(url);
+    return getURL(url);
   },
 
   panelContents() {

app/assets/javascripts/select-kit/addon/components/category-drop.js

@@ -1,3 +1,4 @@
+import getURL from "discourse-common/lib/get-url";
 import I18n from "I18n";
 import { readOnly } from "@ember/object/computed";
 import { computed } from "@ember/object";
@@ -126,14 +127,14 @@ export default ComboBoxComponent.extend({
     "parentCategoryUrl",
     "selectKit.options.subCategory",
     function() {
-      return Discourse.getURL(
+      return getURL(
         this.selectKit.options.subCategory ? this.parentCategoryUrl || "/" : "/"
       );
     }
   ),
 
   noCategoriesUrl: computed("parentCategoryUrl", function() {
-    return Discourse.getURL(`${this.parentCategoryUrl}/none`);
+    return getURL(`${this.parentCategoryUrl}/none`);
   }),
 
   search(filter) {

app/assets/javascripts/select-kit/addon/components/tag-drop.js

@@ -1,3 +1,4 @@
+import getURL from "discourse-common/lib/get-url";
 import Category from "discourse/models/category";
 import { readOnly, or, equal, gte } from "@ember/object/computed";
 import { i18n, setting } from "discourse/lib/computed";
@@ -73,9 +74,9 @@ export default ComboBoxComponent.extend(TagsMixin, {
 
   allTagsUrl: computed("firstCategory", "secondCategory", function() {
     if (this.currentCategory) {
-      return Discourse.getURL(`${this.currentCategoryUrl}?allTags=1`);
+      return getURL(`${this.currentCategoryUrl}?allTags=1`);
     } else {
-      return Discourse.getURL("/");
+      return getURL("/");
     }
   }),
 
@@ -86,7 +87,7 @@ export default ComboBoxComponent.extend(TagsMixin, {
         this.currentCategory.id
       }`;
     }
-    return Discourse.getURL(`${url}/${NONE_TAG_ID}`);
+    return getURL(`${url}/${NONE_TAG_ID}`);
   }),
 
   allTagsLabel: i18n("tagging.selector_all_tags"),
@@ -189,7 +190,7 @@ export default ComboBoxComponent.extend(TagsMixin, {
           }
       }
 
-      DiscourseURL.routeTo(Discourse.getURL(url));
+      DiscourseURL.routeTo(getURL(url));
     }
   }
 });

app/assets/javascripts/select-kit/addon/mixins/tags.js

@@ -1,3 +1,4 @@
+import getURL from "discourse-common/lib/get-url";
 import I18n from "I18n";
 import { reads } from "@ember/object/computed";
 import { ajax } from "discourse/lib/ajax";
@@ -8,7 +9,7 @@ import { isEmpty } from "@ember/utils";
 
 export default Mixin.create({
   searchTags(url, data, callback) {
-    return ajax(Discourse.getURL(url), {
+    return ajax(getURL(url), {
       quietMillis: 200,
       cache: true,
       dataType: "json",

lib/pretty_text.rb

@@ -86,6 +86,7 @@ module PrettyText
     ctx_load_manifest(ctx, "markdown-it-bundle.js")
     root_path = "#{Rails.root}/app/assets/javascripts/"
 
+    apply_es6_file(ctx, root_path, "discourse-common/addon/lib/get-url")
     apply_es6_file(ctx, root_path, "discourse/app/lib/to-markdown")
     apply_es6_file(ctx, root_path, "discourse/app/lib/utilities")
 

test/javascripts/lib/computed-test.js

@@ -9,6 +9,7 @@ import {
   url,
   htmlSafe
 } from "discourse/lib/computed";
+import { setPrefix } from "discourse-common/lib/get-url";
 
 QUnit.module("lib:computed", {
   beforeEach() {
@@ -148,7 +149,7 @@ QUnit.test("url", assert => {
     "it supports urls without a prefix"
   );
 
-  Discourse.BaseUri = "/prefixed";
+  setPrefix("/prefixed");
   t = testClass.create({ username: "eviltrout" });
   assert.equal(
     t.get("userUrl"),

test/javascripts/lib/discourse-test.js

@@ -2,43 +2,6 @@ import { logIn, updateCurrentUser } from "helpers/qunit-helpers";
 
 QUnit.module("lib:discourse");
 
-QUnit.test("getURL on subfolder install", assert => {
-  Discourse.BaseUri = "/forum";
-  assert.equal(Discourse.getURL("/"), "/forum/", "root url has subfolder");
-  assert.equal(
-    Discourse.getURL("/u/neil"),
-    "/forum/u/neil",
-    "relative url has subfolder"
-  );
-
-  assert.equal(
-    Discourse.getURL("/svg-sprite/forum.example.com/svg-sprite.js"),
-    "/forum/svg-sprite/forum.example.com/svg-sprite.js",
-    "works when the url has the prefix in the middle"
-  );
-
-  assert.equal(
-    Discourse.getURL("/forum/t/123"),
-    "/forum/t/123",
-    "does not prefix if the URL is already prefixed"
-  );
-});
-
-QUnit.test("getURLWithCDN on subfolder install with S3", assert => {
-  Discourse.BaseUri = "/forum";
-
-  Discourse.S3CDN = "https://awesome.cdn/site";
-  Discourse.S3BaseUrl = "//test.s3-us-west-1.amazonaws.com/site";
-
-  let url = "//test.s3-us-west-1.amazonaws.com/site/forum/awesome.png";
-  let expected = "https://awesome.cdn/site/forum/awesome.png";
-
-  assert.equal(Discourse.getURLWithCDN(url), expected, "at correct path");
-
-  Discourse.S3CDN = null;
-  Discourse.S3BaseUrl = null;
-});
-
 QUnit.test("title counts are updated correctly", assert => {
   Discourse.set("hasFocus", true);
   Discourse.set("contextCount", 0);

test/javascripts/lib/get-url-test.js

@@ -0,0 +1,88 @@
+import {
+  default as getURL,
+  setupURL,
+  setupS3CDN,
+  getURLWithCDN,
+  isAbsoluteURL,
+  getAbsoluteURL,
+  setPrefix,
+  withoutPrefix
+} from "discourse-common/lib/get-url";
+
+QUnit.module("lib:get-url");
+
+QUnit.test("isAbsoluteURL", assert => {
+  setupURL(null, "https://example.com", "/forum");
+  assert.ok(isAbsoluteURL("https://example.com/test/thing"));
+  assert.ok(!isAbsoluteURL("http://example.com/test/thing"));
+  assert.ok(!isAbsoluteURL("https://discourse.org/test/thing"));
+});
+
+QUnit.test("getAbsoluteURL", assert => {
+  setupURL(null, "https://example.com", "/forum");
+  assert.equal(getAbsoluteURL("/cool/path"), "https://example.com/cool/path");
+});
+
+QUnit.test("withoutPrefix", assert => {
+  setPrefix("/eviltrout");
+  assert.equal(withoutPrefix("/eviltrout/hello"), "/hello");
+  assert.equal(withoutPrefix("/eviltrout/"), "/");
+  assert.equal(withoutPrefix("/eviltrout"), "");
+
+  setPrefix("");
+  assert.equal(withoutPrefix("/eviltrout/hello"), "/eviltrout/hello");
+  assert.equal(withoutPrefix("/eviltrout"), "/eviltrout");
+  assert.equal(withoutPrefix("/"), "/");
+
+  setPrefix(null);
+  assert.equal(withoutPrefix("/eviltrout/hello"), "/eviltrout/hello");
+  assert.equal(withoutPrefix("/eviltrout"), "/eviltrout");
+  assert.equal(withoutPrefix("/"), "/");
+});
+
+QUnit.test("getURL with empty paths", assert => {
+  setupURL(null, "https://example.com", "/");
+  assert.equal(getURL("/"), "/");
+  assert.equal(getURL(""), "");
+  setupURL(null, "https://example.com", "");
+  assert.equal(getURL("/"), "/");
+  assert.equal(getURL(""), "");
+  setupURL(null, "https://example.com", undefined);
+  assert.equal(getURL("/"), "/");
+  assert.equal(getURL(""), "");
+});
+
+QUnit.test("getURL on subfolder install", assert => {
+  setupURL(null, "", "/forum");
+  assert.equal(getURL("/"), "/forum/", "root url has subfolder");
+  assert.equal(
+    getURL("/u/neil"),
+    "/forum/u/neil",
+    "relative url has subfolder"
+  );
+
+  assert.equal(
+    getURL("/svg-sprite/forum.example.com/svg-sprite.js"),
+    "/forum/svg-sprite/forum.example.com/svg-sprite.js",
+    "works when the url has the prefix in the middle"
+  );
+
+  assert.equal(
+    getURL("/forum/t/123"),
+    "/forum/t/123",
+    "does not prefix if the URL is already prefixed"
+  );
+});
+
+QUnit.test("getURLWithCDN on subfolder install with S3", assert => {
+  setupURL(null, "", "/forum");
+  setupS3CDN(
+    "//test.s3-us-west-1.amazonaws.com/site",
+    "https://awesome.cdn/site"
+  );
+
+  let url = "//test.s3-us-west-1.amazonaws.com/site/forum/awesome.png";
+  let expected = "https://awesome.cdn/site/forum/awesome.png";
+
+  assert.equal(getURLWithCDN(url), expected, "at correct path");
+});

test/javascripts/lib/url-test.js

@@ -1,4 +1,5 @@
 import DiscourseURL, { userPath } from "discourse/lib/url";
+import { setPrefix } from "discourse-common/lib/get-url";
 
 QUnit.module("lib:url");
 
@@ -59,8 +60,8 @@ QUnit.test("userPath", assert => {
   assert.equal(userPath("hp.json"), "/u/hp.json");
 });
 
-QUnit.test("userPath with BaseUri", assert => {
-  Discourse.BaseUri = "/forum";
+QUnit.test("userPath with prefix", assert => {
+  setPrefix("/forum");
   assert.equal(userPath(), "/forum/u");
   assert.equal(userPath("eviltrout"), "/forum/u/eviltrout");
   assert.equal(userPath("hp.json"), "/forum/u/hp.json");

test/javascripts/models/email-log-test.js

@@ -1,4 +1,5 @@
 import EmailLog from "admin/models/email-log";
+import { setPrefix } from "discourse-common/lib/get-url";
 
 QUnit.module("Discourse.EmailLog");
 
@@ -7,7 +8,7 @@ QUnit.test("create", assert => {
 });
 
 QUnit.test("subfolder support", assert => {
-  Discourse.BaseUri = "/forum";
+  setPrefix("/forum");
   const attrs = {
     id: 60,
     to_address: "wikiman@asdf.com",

test/javascripts/models/report-test.js

@@ -1,4 +1,5 @@
 import Report from "admin/models/report";
+import { setPrefix } from "discourse-common/lib/get-url";
 
 QUnit.module("Report");
 
@@ -528,7 +529,7 @@ QUnit.test("computed labels", assert => {
   assert.equal(computedFilesizeLabel.value, 582641);
 
   // subfolder support
-  Discourse.BaseUri = "/forum";
+  setPrefix("/forum");
 
   const postLink = computedLabels[5].compute(row).formatedValue;
   assert.equal(

test/javascripts/test_helper.js

@@ -151,8 +151,10 @@ QUnit.testStart(function(ctx) {
 
   // Allow our tests to change site settings and have them reset before the next test
   Discourse.SiteSettings = dup(Discourse.SiteSettingsOriginal);
-  Discourse.BaseUri = "";
-  Discourse.BaseUrl = "http://localhost:3000";
+
+  let getURL = require("discourse-common/lib/get-url");
+  getURL.setupURL(null, "http://localhost:3000", "");
+  getURL.setupS3CDN(null, null);
 
   let User = require("discourse/models/user").default;
   let Session = require("discourse/models/session").default;

test/javascripts/widgets/home-logo-test.js

@@ -1,4 +1,5 @@
 import { moduleForWidget, widgetTest } from "helpers/widget-test";
+import { setPrefix } from "discourse-common/lib/get-url";
 
 moduleForWidget("home-logo");
 
@@ -101,7 +102,7 @@ widgetTest("mobile without logo", {
 widgetTest("basics, subfolder", {
   template: '{{mount-widget widget="home-logo" args=args}}',
   beforeEach() {
-    Discourse.BaseUri = "/forum";
+    setPrefix("/forum");
     this.siteSettings.site_logo_url = bigLogo;
     this.siteSettings.site_logo_small_url = smallLogo;
     this.siteSettings.title = title;
@@ -118,7 +119,7 @@ widgetTest("basics, subfolder", {
 widgetTest("basics, subfolder - minimized", {
   template: '{{mount-widget widget="home-logo" args=args}}',
   beforeEach() {
-    Discourse.BaseUri = "/forum";
+    setPrefix("/forum");
     this.siteSettings.site_logo_url = bigLogo;
     this.siteSettings.site_logo_small_url = smallLogo;
     this.siteSettings.title = title;
@@ -135,7 +136,7 @@ widgetTest("basics, subfolder - minimized", {
 widgetTest("mobile logo, subfolder", {
   template: '{{mount-widget widget="home-logo" args=args}}',
   beforeEach() {
-    Discourse.BaseUri = "/forum";
+    setPrefix("/forum");
     this.siteSettings.site_mobile_logo_url = mobileLogo;
     this.siteSettings.site_logo_small_url = smallLogo;
     this.site.mobileView = true;