From d5a37a18bd5e41d7a08b214f06481f830414def3 Mon Sep 17 00:00:00 2001
From: ochafik <olivier.chafik@gmail.com>
Date: Sun, 11 Jan 2026 13:33:43 +0000
Subject: [PATCH] fix: add error handling for server startup failures
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Previously, if app.listen() failed (e.g., port already in use), the
server would fail silently. This adds proper error handling to log
the error and exit with a non-zero status code.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
---
 examples/basic-server-preact/server-utils.ts          | 6 +++++-
 examples/basic-server-react/server-utils.ts           | 6 +++++-
 examples/basic-server-solid/server-utils.ts           | 6 +++++-
 examples/basic-server-svelte/server-utils.ts          | 6 +++++-
 examples/basic-server-vanillajs/server-utils.ts       | 6 +++++-
 examples/basic-server-vue/server-utils.ts             | 6 +++++-
 examples/budget-allocator-server/server-utils.ts      | 6 +++++-
 examples/cohort-heatmap-server/server-utils.ts        | 6 +++++-
 examples/customer-segmentation-server/server-utils.ts | 6 +++++-
 examples/integration-server/server-utils.ts           | 6 +++++-
 examples/scenario-modeler-server/server-utils.ts      | 6 +++++-
 examples/sheet-music-server/server-utils.ts           | 6 +++++-
 examples/system-monitor-server/server-utils.ts        | 6 +++++-
 examples/threejs-server/server-utils.ts               | 6 +++++-
 examples/video-resource-server/server-utils.ts        | 6 +++++-
 examples/wiki-explorer-server/server-utils.ts         | 6 +++++-
 16 files changed, 80 insertions(+), 16 deletions(-)

diff --git a/examples/basic-server-preact/server-utils.ts b/examples/basic-server-preact/server-utils.ts
index c700c818..9fe9745a 100644
--- a/examples/basic-server-preact/server-utils.ts
+++ b/examples/basic-server-preact/server-utils.ts
@@ -54,7 +54,11 @@ export async function startServer(
     }
   });
 
-  const httpServer = app.listen(port, () => {
+  const httpServer = app.listen(port, (err) => {
+    if (err) {
+      console.error("Failed to start server:", err);
+      process.exit(1);
+    }
     console.log(`${name} listening on http://localhost:${port}/mcp`);
   });
 
diff --git a/examples/basic-server-react/server-utils.ts b/examples/basic-server-react/server-utils.ts
index c700c818..9fe9745a 100644
--- a/examples/basic-server-react/server-utils.ts
+++ b/examples/basic-server-react/server-utils.ts
@@ -54,7 +54,11 @@ export async function startServer(
     }
   });
 
-  const httpServer = app.listen(port, () => {
+  const httpServer = app.listen(port, (err) => {
+    if (err) {
+      console.error("Failed to start server:", err);
+      process.exit(1);
+    }
     console.log(`${name} listening on http://localhost:${port}/mcp`);
   });
 
diff --git a/examples/basic-server-solid/server-utils.ts b/examples/basic-server-solid/server-utils.ts
index c700c818..9fe9745a 100644
--- a/examples/basic-server-solid/server-utils.ts
+++ b/examples/basic-server-solid/server-utils.ts
@@ -54,7 +54,11 @@ export async function startServer(
     }
   });
 
-  const httpServer = app.listen(port, () => {
+  const httpServer = app.listen(port, (err) => {
+    if (err) {
+      console.error("Failed to start server:", err);
+      process.exit(1);
+    }
     console.log(`${name} listening on http://localhost:${port}/mcp`);
   });
 
diff --git a/examples/basic-server-svelte/server-utils.ts b/examples/basic-server-svelte/server-utils.ts
index c700c818..9fe9745a 100644
--- a/examples/basic-server-svelte/server-utils.ts
+++ b/examples/basic-server-svelte/server-utils.ts
@@ -54,7 +54,11 @@ export async function startServer(
     }
   });
 
-  const httpServer = app.listen(port, () => {
+  const httpServer = app.listen(port, (err) => {
+    if (err) {
+      console.error("Failed to start server:", err);
+      process.exit(1);
+    }
     console.log(`${name} listening on http://localhost:${port}/mcp`);
   });
 
diff --git a/examples/basic-server-vanillajs/server-utils.ts b/examples/basic-server-vanillajs/server-utils.ts
index c700c818..9fe9745a 100644
--- a/examples/basic-server-vanillajs/server-utils.ts
+++ b/examples/basic-server-vanillajs/server-utils.ts
@@ -54,7 +54,11 @@ export async function startServer(
     }
   });
 
-  const httpServer = app.listen(port, () => {
+  const httpServer = app.listen(port, (err) => {
+    if (err) {
+      console.error("Failed to start server:", err);
+      process.exit(1);
+    }
     console.log(`${name} listening on http://localhost:${port}/mcp`);
   });
 
diff --git a/examples/basic-server-vue/server-utils.ts b/examples/basic-server-vue/server-utils.ts
index c700c818..9fe9745a 100644
--- a/examples/basic-server-vue/server-utils.ts
+++ b/examples/basic-server-vue/server-utils.ts
@@ -54,7 +54,11 @@ export async function startServer(
     }
   });
 
-  const httpServer = app.listen(port, () => {
+  const httpServer = app.listen(port, (err) => {
+    if (err) {
+      console.error("Failed to start server:", err);
+      process.exit(1);
+    }
     console.log(`${name} listening on http://localhost:${port}/mcp`);
   });
 
diff --git a/examples/budget-allocator-server/server-utils.ts b/examples/budget-allocator-server/server-utils.ts
index c700c818..9fe9745a 100644
--- a/examples/budget-allocator-server/server-utils.ts
+++ b/examples/budget-allocator-server/server-utils.ts
@@ -54,7 +54,11 @@ export async function startServer(
     }
   });
 
-  const httpServer = app.listen(port, () => {
+  const httpServer = app.listen(port, (err) => {
+    if (err) {
+      console.error("Failed to start server:", err);
+      process.exit(1);
+    }
     console.log(`${name} listening on http://localhost:${port}/mcp`);
   });
 
diff --git a/examples/cohort-heatmap-server/server-utils.ts b/examples/cohort-heatmap-server/server-utils.ts
index c700c818..9fe9745a 100644
--- a/examples/cohort-heatmap-server/server-utils.ts
+++ b/examples/cohort-heatmap-server/server-utils.ts
@@ -54,7 +54,11 @@ export async function startServer(
     }
   });
 
-  const httpServer = app.listen(port, () => {
+  const httpServer = app.listen(port, (err) => {
+    if (err) {
+      console.error("Failed to start server:", err);
+      process.exit(1);
+    }
     console.log(`${name} listening on http://localhost:${port}/mcp`);
   });
 
diff --git a/examples/customer-segmentation-server/server-utils.ts b/examples/customer-segmentation-server/server-utils.ts
index c700c818..9fe9745a 100644
--- a/examples/customer-segmentation-server/server-utils.ts
+++ b/examples/customer-segmentation-server/server-utils.ts
@@ -54,7 +54,11 @@ export async function startServer(
     }
   });
 
-  const httpServer = app.listen(port, () => {
+  const httpServer = app.listen(port, (err) => {
+    if (err) {
+      console.error("Failed to start server:", err);
+      process.exit(1);
+    }
     console.log(`${name} listening on http://localhost:${port}/mcp`);
   });
 
diff --git a/examples/integration-server/server-utils.ts b/examples/integration-server/server-utils.ts
index c700c818..9fe9745a 100644
--- a/examples/integration-server/server-utils.ts
+++ b/examples/integration-server/server-utils.ts
@@ -54,7 +54,11 @@ export async function startServer(
     }
   });
 
-  const httpServer = app.listen(port, () => {
+  const httpServer = app.listen(port, (err) => {
+    if (err) {
+      console.error("Failed to start server:", err);
+      process.exit(1);
+    }
     console.log(`${name} listening on http://localhost:${port}/mcp`);
   });
 
diff --git a/examples/scenario-modeler-server/server-utils.ts b/examples/scenario-modeler-server/server-utils.ts
index c700c818..9fe9745a 100644
--- a/examples/scenario-modeler-server/server-utils.ts
+++ b/examples/scenario-modeler-server/server-utils.ts
@@ -54,7 +54,11 @@ export async function startServer(
     }
   });
 
-  const httpServer = app.listen(port, () => {
+  const httpServer = app.listen(port, (err) => {
+    if (err) {
+      console.error("Failed to start server:", err);
+      process.exit(1);
+    }
     console.log(`${name} listening on http://localhost:${port}/mcp`);
   });
 
diff --git a/examples/sheet-music-server/server-utils.ts b/examples/sheet-music-server/server-utils.ts
index c700c818..9fe9745a 100644
--- a/examples/sheet-music-server/server-utils.ts
+++ b/examples/sheet-music-server/server-utils.ts
@@ -54,7 +54,11 @@ export async function startServer(
     }
   });
 
-  const httpServer = app.listen(port, () => {
+  const httpServer = app.listen(port, (err) => {
+    if (err) {
+      console.error("Failed to start server:", err);
+      process.exit(1);
+    }
     console.log(`${name} listening on http://localhost:${port}/mcp`);
   });
 
diff --git a/examples/system-monitor-server/server-utils.ts b/examples/system-monitor-server/server-utils.ts
index c700c818..9fe9745a 100644
--- a/examples/system-monitor-server/server-utils.ts
+++ b/examples/system-monitor-server/server-utils.ts
@@ -54,7 +54,11 @@ export async function startServer(
     }
   });
 
-  const httpServer = app.listen(port, () => {
+  const httpServer = app.listen(port, (err) => {
+    if (err) {
+      console.error("Failed to start server:", err);
+      process.exit(1);
+    }
     console.log(`${name} listening on http://localhost:${port}/mcp`);
   });
 
diff --git a/examples/threejs-server/server-utils.ts b/examples/threejs-server/server-utils.ts
index c700c818..9fe9745a 100644
--- a/examples/threejs-server/server-utils.ts
+++ b/examples/threejs-server/server-utils.ts
@@ -54,7 +54,11 @@ export async function startServer(
     }
   });
 
-  const httpServer = app.listen(port, () => {
+  const httpServer = app.listen(port, (err) => {
+    if (err) {
+      console.error("Failed to start server:", err);
+      process.exit(1);
+    }
     console.log(`${name} listening on http://localhost:${port}/mcp`);
   });
 
diff --git a/examples/video-resource-server/server-utils.ts b/examples/video-resource-server/server-utils.ts
index c700c818..9fe9745a 100644
--- a/examples/video-resource-server/server-utils.ts
+++ b/examples/video-resource-server/server-utils.ts
@@ -54,7 +54,11 @@ export async function startServer(
     }
   });
 
-  const httpServer = app.listen(port, () => {
+  const httpServer = app.listen(port, (err) => {
+    if (err) {
+      console.error("Failed to start server:", err);
+      process.exit(1);
+    }
     console.log(`${name} listening on http://localhost:${port}/mcp`);
   });
 
diff --git a/examples/wiki-explorer-server/server-utils.ts b/examples/wiki-explorer-server/server-utils.ts
index c700c818..9fe9745a 100644
--- a/examples/wiki-explorer-server/server-utils.ts
+++ b/examples/wiki-explorer-server/server-utils.ts
@@ -54,7 +54,11 @@ export async function startServer(
     }
   });
 
-  const httpServer = app.listen(port, () => {
+  const httpServer = app.listen(port, (err) => {
+    if (err) {
+      console.error("Failed to start server:", err);
+      process.exit(1);
+    }
     console.log(`${name} listening on http://localhost:${port}/mcp`);
   });