FIX: forces boolean when content is only "true" && "false"

app/assets/javascripts/discourse/templates/components/edit-category-settings.hbs

@@ -69,7 +69,7 @@
   <div class="controls">
   {{combo-box valueAttribute="value" content=availableSorts value=category.sort_order none="category.sort_options.default"}}
   {{#unless isDefaultSortOrder}}
-    {{combo-box valueAttribute="value" content=sortAscendingOptions value=category.sort_ascending none="category.sort_options.default"}}
+    {{combo-box castBoolean=true valueAttribute="value" content=sortAscendingOptions value=category.sort_ascending none="category.sort_options.default"}}
   {{/unless}}
     </div>
 </section>

app/assets/javascripts/select-kit/components/multi-select.js.es6

@@ -79,7 +79,7 @@ export default SelectKitComponent.extend({
   shouldDisplayFilter() { return true; },
 
   _beforeWillComputeValues(values) {
-    return values.map(v => this._castInteger(v === "" ? null : v));
+    return values.map(v => this._cast(v === "" ? null : v));
   },
   willComputeValues(values) { return values; },
   computeValues(values) { return values; },

app/assets/javascripts/select-kit/components/select-kit.js.es6

@@ -62,6 +62,7 @@ export default Ember.Component.extend(UtilsMixin, PluginApiMixin, DomHelpersMixi
   horizontalOffset: 0,
   fullWidthOnMobile: false,
   castInteger: false,
+  castBoolean: false,
   allowAny: false,
   allowInitialValueMutation: false,
   content: null,
@@ -169,7 +170,7 @@ export default Ember.Component.extend(UtilsMixin, PluginApiMixin, DomHelpersMixi
     }
 
     let computedContentItem = {
-      value: this._castInteger(this.valueForContentItem(contentItem)),
+      value: this._cast(this.valueForContentItem(contentItem)),
       name: name || this._nameForContent(contentItem),
       locked: false,
       created: options.created || false,

app/assets/javascripts/select-kit/components/single-select.js.es6

@@ -63,7 +63,7 @@ export default SelectKitComponent.extend({
     switch (typeof value) {
     case "string":
     case "number":
-      return this._castInteger(value === "" ? null : value);
+      return this._cast(value === "" ? null : value);
     default:
       return value;
     }

app/assets/javascripts/select-kit/mixins/utils.js.es6

@@ -27,6 +27,19 @@ export default Ember.Mixin.create({
     return !isNaN(parseFloat(input)) && isFinite(input);
   },
 
+  _cast(value) {
+    if (value === this.noneValue) return value;
+    return this._castInteger(this._castBoolean(value));
+  },
+
+  _castBoolean(value) {
+    if (this.get("castBoolean") && Ember.isPresent(value) && typeof(value) === "string") {
+      return value === "true";
+    }
+
+    return value;
+  },
+
   _castInteger(value) {
     if (this.get("castInteger") && Ember.isPresent(value) && this._isNumeric(value)) {
       return parseInt(value, 10);

test/javascripts/components/single-select-test.js.es6

@@ -232,6 +232,33 @@ componentTest('supports converting select value to integer', {
   }
 });
 
+componentTest('supports converting string as boolean to boolean', {
+  template: '{{single-select value=value content=content castBoolean=true}}',
+
+  beforeEach() {
+    this.set('value', true);
+    this.set('content', [{ id: 'true', name: 'ASC'}, {id: 'false', name: 'DESC' }]);
+  },
+
+  test(assert) {
+    this.get('subject').expand();
+
+    andThen(() => assert.equal(this.get('subject').selectedRow().name(), 'ASC') );
+
+    andThen(() => {
+      this.set('value', false);
+    });
+
+    andThen(() => {
+      assert.equal(
+        this.get('subject').selectedRow().name(),
+        'DESC',
+        'it works with dynamic content'
+      );
+    });
+  }
+});
+
 componentTest('supports keyboard events', {
   template: '{{single-select content=content filterable=true}}',