Use async/await instead of explicit promises

dist/converse.js

@@ -64494,27 +64494,20 @@ _converse_core__WEBPACK_IMPORTED_MODULE_0__["default"].plugins.add('converse-dis
         });
       },
 
-      hasFeature(feature) {
+      async hasFeature(feature) {
         /* Returns a Promise which resolves with a map indicating
          * whether a given feature is supported.
          *
          * Parameters:
          *    (String) feature - The feature that might be supported.
          */
-        const entity = this;
-        return new Promise((resolve, reject) => {
-          function fulfillPromise() {
-            if (entity.features.findWhere({
+        await this.waitUntilFeaturesDiscovered;
+
+        if (this.features.findWhere({
           'var': feature
         })) {
-              resolve(entity);
-            } else {
-              resolve();
-            }
+          return this;
         }
-
-          entity.waitUntilFeaturesDiscovered.then(fulfillPromise).catch(_.partial(_converse.log, _, Strophe.LogLevel.FATAL));
-        });
       },
 
       onFeatureAdded(feature) {

src/headless/converse-disco.js

@@ -79,26 +79,17 @@ converse.plugins.add('converse-disco', {
                 });
             },
 
-            hasFeature (feature) {
+            async hasFeature (feature) {
                 /* Returns a Promise which resolves with a map indicating
                  * whether a given feature is supported.
                  *
                  * Parameters:
                  *    (String) feature - The feature that might be supported.
                  */
-                const entity = this;
-                return new Promise((resolve, reject) => {
-                    function fulfillPromise () {
-                        if (entity.features.findWhere({'var': feature})) {
-                            resolve(entity);
-                        } else {
-                            resolve();
-                        }
+                await this.waitUntilFeaturesDiscovered
+                if (this.features.findWhere({'var': feature})) {
+                    return this;
                 }
-                    entity.waitUntilFeaturesDiscovered
-                        .then(fulfillPromise)
-                        .catch(_.partial(_converse.log, _, Strophe.LogLevel.FATAL));
-                });
             },
 
             onFeatureAdded (feature) {