fix: add selectedIndex and value setter

Author: luwes

src/option.js

@@ -53,7 +53,7 @@ class OptionElement extends globalThis.HTMLElement {
     }
 
     if (name === 'disabled') {
-      this.#internals.ariaDisabled = newVal != null ? 'true' : 'false';
+      this.#internals.ariaDisabled = this.disabled ? 'true' : 'false';
       this.#ownerElement()?.reset();
     }
   }

src/selectmenu.js

@@ -155,16 +155,22 @@ class SelectMenuElement extends globalThis.HTMLElement {
     return this.options.findIndex(option => option.selected);
   }
 
-  set selectedIndex(val) {
-
+  set selectedIndex(index) {
+    const option = this.options.find(option => option.index === index);
+    if (option) {
+      this.#selectOption(option);
+    }
   }
 
   get value() {
     return this.options.find(option => option.selected)?.value ?? '';
   }
 
   set value(val) {
-
+    const option = this.options.find(option => option.value === val);
+    if (option) {
+      this.#selectOption(option);
+    }
   }
 
   get required() {

test/test.js

@@ -25,6 +25,32 @@ test('selectmenu selects the option w/ selected attribute', async function (t) {
   t.equal(selectmenu.selectedIndex, 1);
 });
 
+test('selectmenu.selectedIndex selects the option w/ index', async function (t) {
+  const selectmenu = await fixture(`
+    <x-selectmenu>
+      <x-option>Option 1</x-option>
+      <x-option>Option 2</x-option>
+    </x-selectmenu>`);
+
+  selectmenu.selectedIndex = 1;
+
+  t.equal(selectmenu.value, 'Option 2');
+  t.equal(selectmenu.selectedIndex, 1);
+});
+
+test('selectmenu.value selects the option w/ value', async function (t) {
+  const selectmenu = await fixture(`
+    <x-selectmenu>
+      <x-option>Option 1</x-option>
+      <x-option>Option 2</x-option>
+    </x-selectmenu>`);
+
+  selectmenu.value = 'Option 2';
+
+  t.equal(selectmenu.value, 'Option 2');
+  t.equal(selectmenu.selectedIndex, 1);
+});
+
 function delay(ms) {
   return new Promise((resolve) => setTimeout(resolve, ms));
 }