DEV: Support custom icon when adding custom link to sidebar via plugin API (#21760)

app/assets/javascripts/discourse/app/lib/plugin-api.js

@@ -1848,10 +1848,11 @@ class PluginApi {
    *
    * @param {(addCommunitySectionLinkCallback|Object)} arg - A callback function or an Object.
    * @param {string} arg.name - The name of the link. Needs to be dasherized and lowercase.
-   * @param {string=} arg.route - The Ember route name to generate the href attribute for the link.
-   * @param {string=} arg.href - The href attribute for the link.
    * @param {string} arg.title - The title attribute for the link.
    * @param {string} arg.text - The text to display for the link.
+   * @param {string} [arg.route] - The Ember route name to generate the href attribute for the link.
+   * @param {string} [arg.href] - The href attribute for the link.
+   * @param {string} [arg.icon] - The FontAwesome icon to display for the link.
    * @param {Boolean} [secondary] - Determines whether the section link should be added to the main or secondary section in the "More..." links drawer.
    */
   addCommunitySectionLink(arg, secondary) {
@@ -1904,7 +1905,7 @@ class PluginApi {
    * @param {Object} arg - An object
    * @param {string} arg.badgeTextFunction - Function used to generate the text for the badge displayed in the section link.
    * @param {string} arg.route - The Ember route name to generate the href attribute for the link.
-   * @param {Object=} arg.routeQuery - Object representing the query params that should be appended to the route generated.
+   * @param {Object} [arg.routeQuery] - Object representing the query params that should be appended to the route generated.
    * @param {shouldRegister} arg.shouldRegister - Function used to determine if the countable should be registered for the category.
    * @param {refreshCountFunction} arg.refreshCountFunction - Function used to calculate the value used to set the property for the count whenever the sidebar section link refreshes.
    * @param {prioritizeOverDefaults} args.prioritizeOverDefaults - Function used to determine whether the countable should be prioritized over the default countables of unread/new.

app/assets/javascripts/discourse/app/lib/sidebar/custom-community-section-links.js

@@ -13,10 +13,11 @@ export let secondaryCustomSectionLinks = [];
  *
  * @param {(addSectionLinkCallback|Object)} args - A callback function or an Object.
  * @param {string} args.name - The name of the link. Needs to be dasherized and lowercase.
- * @param {string=} args.route - The Ember route name to generate the href attribute for the link.
- * @param {string=} args.href - The href attribute for the link.
- * @param {string=} args.title - The title attribute for the link.
  * @param {string} args.text - The text to display for the link.
+ * @param {string} [args.route] - The Ember route name to generate the href attribute for the link.
+ * @param {string} [args.href] - The href attribute for the link.
+ * @param {string} [args.title] - The title attribute for the link.
+ * @param {string} [args.icon] - The FontAwesome 5 icon to display for the link.
  * @param {Boolean} [secondary] - Determines whether the section link should be added to the main or secondary section in the "More..." links drawer.
  */
 export function addSectionLink(args, secondary) {
@@ -65,6 +66,10 @@ export function addSectionLink(args, secondary) {
       get title() {
         return args.title;
       }
+
+      get prefixValue() {
+        return args.icon || super.prefixValue;
+      }
     };
 
     links.push(klass);

app/assets/javascripts/discourse/tests/acceptance/sidebar-user-community-section-test.js

@@ -1065,6 +1065,7 @@ acceptance("Sidebar - Logged on user - Community Section", function (needs) {
         route: "discovery.unread",
         text: "unread topics",
         title: "List of unread topics",
+        icon: "wrench",
       });
     });
 
@@ -1088,6 +1089,13 @@ acceptance("Sidebar - Logged on user - Community Section", function (needs) {
       "displays the right title for the link"
     );
 
+    assert.ok(
+      exists(
+        ".sidebar-section-link[data-link-name='unread'] .sidebar-section-link-prefix.icon .d-icon-wrench"
+      ),
+      "displays the wrench icon for the link"
+    );
+
     await click(".sidebar-section-link[data-link-name='unread']");
 
     assert.strictEqual(currentURL(), "/unread", "links to the right URL");
@@ -1154,6 +1162,13 @@ acceptance("Sidebar - Logged on user - Community Section", function (needs) {
       "displays the right title for the link"
     );
 
+    assert.ok(
+      exists(
+        ".sidebar-section-link[data-link-name='user-summary'] .sidebar-section-link-prefix.icon .d-icon-link"
+      ),
+      "displays the link icon for the link"
+    );
+
     await click(".btn-sidebar-toggle");
 
     assert.ok(teardownCalled, "section link teardown callback was called");