From db96e8cc07e2b73e9a2a3b3023b1dc572daeeb89 Mon Sep 17 00:00:00 2001
From: Gyulai Levente <47368351+gyulus3@users.noreply.github.com>
Date: Fri, 1 Dec 2023 09:57:19 +0100
Subject: [PATCH] fix(tabs): set selectedIndex only if differ from previous
 selectedIndex

---
 .changeset/small-pumpkins-peel.md                  | 5 +++++
 packages/ui/components/tabs/src/LionTabs.js        | 4 ++++
 packages/ui/components/tabs/test/lion-tabs.test.js | 8 ++++++++
 3 files changed, 17 insertions(+)
 create mode 100644 .changeset/small-pumpkins-peel.md

diff --git a/.changeset/small-pumpkins-peel.md b/.changeset/small-pumpkins-peel.md
new file mode 100644
index 0000000000..0fcb13cae9
--- /dev/null
+++ b/.changeset/small-pumpkins-peel.md
@@ -0,0 +1,5 @@
+---
+'@lion/ui': patch
+---
+
+fix(tabs): set selectedIndex only if value differ from previous value
diff --git a/packages/ui/components/tabs/src/LionTabs.js b/packages/ui/components/tabs/src/LionTabs.js
index 493ef171f0..bb9849acc9 100644
--- a/packages/ui/components/tabs/src/LionTabs.js
+++ b/packages/ui/components/tabs/src/LionTabs.js
@@ -356,7 +356,11 @@ export class LionTabs extends LitElement {
    * @param {number} value The new index
    */
   set selectedIndex(value) {
+    if (value === this.__selectedIndex) {
+      return;
+    }
     const stale = this.__selectedIndex;
+    /** @type {number | undefined} */
     this.__selectedIndex = value;
     this.__updateSelected(false);
     this.dispatchEvent(new Event('selected-changed'));
diff --git a/packages/ui/components/tabs/test/lion-tabs.test.js b/packages/ui/components/tabs/test/lion-tabs.test.js
index d3f8b4979e..6511a0566d 100644
--- a/packages/ui/components/tabs/test/lion-tabs.test.js
+++ b/packages/ui/components/tabs/test/lion-tabs.test.js
@@ -75,6 +75,14 @@ describe('<lion-tabs>', () => {
       expect(spy).to.have.been.calledOnce;
     });
 
+    it('does not send event "selected-changed" after selecting currently selected tab', async () => {
+      const el = /** @type {LionTabs} */ (await fixture(basicTabs));
+      const spy = sinon.spy();
+      el.addEventListener('selected-changed', spy);
+      el.selectedIndex = 0;
+      expect(spy).not.to.have.been.called;
+    });
+
     it('logs warning if unequal amount of tabs and panels', async () => {
       const stub = sinon.stub(console, 'warn');
       await fixture(html`