From 029f36d97782781ef72d3ae7d476ed5da766c29a Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Wed, 25 Feb 2026 11:06:06 +0000
Subject: [PATCH 1/2] Initial plan


From 810c15c0fe5243e85800ef892be54959626a60bf Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Wed, 25 Feb 2026 11:19:29 +0000
Subject: [PATCH 2/2] fix: use HTTP check instead of detect-port for dev/serve
 ready() to prevent EADDRINUSE

Co-authored-by: valentinpalkovic <5889929+valentinpalkovic@users.noreply.github.com>
---
 scripts/tasks/dev.ts   | 8 ++++++--
 scripts/tasks/serve.ts | 8 ++++++--
 2 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/scripts/tasks/dev.ts b/scripts/tasks/dev.ts
index 71c0bc8f6a0c..268e8d1862ec 100644
--- a/scripts/tasks/dev.ts
+++ b/scripts/tasks/dev.ts
@@ -1,4 +1,3 @@
-import detectFreePort from 'detect-port';
 import waitOn from 'wait-on';
 
 import type { AllTemplatesKey } from '../../code/lib/cli-storybook/src/sandbox-templates';
@@ -21,7 +20,12 @@ export const dev: Task = {
   dependsOn: ['sandbox'],
   async ready({ key }) {
     const port = getDevPort(key);
-    return (await detectFreePort(port)) !== port;
+    try {
+      await fetch(`http://localhost:${port}/iframe.html`, { signal: AbortSignal.timeout(1000) });
+      return true;
+    } catch {
+      return false;
+    }
   },
   async run({ sandboxDir, key, selectedTask }, { dryRun, debug }) {
     const controller = new AbortController();
diff --git a/scripts/tasks/serve.ts b/scripts/tasks/serve.ts
index 05e80006d620..6a5ee9513ceb 100644
--- a/scripts/tasks/serve.ts
+++ b/scripts/tasks/serve.ts
@@ -1,4 +1,3 @@
-import detectFreePort from 'detect-port';
 import waitOn from 'wait-on';
 
 import type { AllTemplatesKey } from '../../code/lib/cli-storybook/src/sandbox-templates';
@@ -21,7 +20,12 @@ export const serve: Task = {
   dependsOn: ['build'],
   async ready({ key }) {
     const port = getServePort(key);
-    return (await detectFreePort(port)) !== port;
+    try {
+      await fetch(`http://localhost:${port}/iframe.html`, { signal: AbortSignal.timeout(1000) });
+      return true;
+    } catch {
+      return false;
+    }
   },
   async run({ builtSandboxDir, key }, { debug, dryRun }) {
     const port = getServePort(key);