Attempt to set up until it works

Author: camertron

.tool-versions

@@ -0,0 +1 @@
+nodejs 22.3.0

custom-elements.json

@@ -437,6 +437,9 @@
               "kind": "field",
               "name": "#tabList",
               "privacy": "private",
+              "type": {
+                "text": "HTMLElement"
+              },
               "readonly": true
             },
             {

src/tab-container-element.ts

@@ -220,14 +220,13 @@ export class TabContainerElement extends HTMLElement {
     this.addEventListener('keydown', this)
     this.addEventListener('click', this)
 
-    if (this.#tabs.length > 0) {
-      this.selectTab(-1)
-      this.#setupComplete = true
-    } else {
+    this.selectTab(-1)
+
+    if (!this.#setupComplete) {
       const mutationObserver = new MutationObserver(() => {
-        if (this.#tabs.length > 0) {
-          this.selectTab(-1)
-          this.#setupComplete = true
+        this.selectTab(-1)
+
+        if (this.#setupComplete) {
           mutationObserver.disconnect()
         }
       })
@@ -413,5 +412,7 @@ export class TabContainerElement extends HTMLElement {
         }),
       )
     }
+
+    this.#setupComplete = true
   }
 }

test/test.js

@@ -339,11 +339,9 @@ describe('tab-container', function () {
     })
 
     it('result in noop, when selectTab receives out of bounds index', function () {
-      assert.throws(() => tabContainer.selectTab(3), 'Index "3" out of bounds')
-
-      tabContainer.selectTab(2)
-      assert.deepStrictEqual(tabs.map(isSelected), [false, false, true], 'Third tab is selected')
-      assert.deepStrictEqual(panels.map(isHidden), [true, true, false], 'Third panel is visible')
+      tabContainer.selectTab(3)
+      assert.deepStrictEqual(tabs.map(isSelected), [true, false, false], 'First tab is selected')
+      assert.deepStrictEqual(panels.map(isHidden), [false, true, true], 'First panel is visible')
     })
   })