adding SIGTERM kill first, only then SIGKILL

Author: TomasRup

src/client/stdio.ts

@@ -192,9 +192,34 @@ export class StdioClientTransport implements Transport {
     }
   }
 
+  private gracefullyExitProcess(): void {
+    const pid = this.pid;
+    
+    if (!pid) {
+      return;
+    }
+
+    // Killing after 3 seconds to ensure the process has time to exit gracefully.
+    setTimeout(() => {
+      try {
+        process.kill(pid, "SIGKILL");
+
+      } catch (err) {
+        if (typeof err === "object" && err !== null && "code" in err && err.code === "ESRCH") {
+          // Ignoring ESRCH error, which means the process is already dead.
+          return;
+        }
+
+        console.warn(`Failed to kill process ${pid}: ${err}`);
+      }
+    }, 3000);
+
+    process.kill(pid, "SIGINT");
+  }
+
   async close(): Promise<void> {
     this._abortController.abort();
-    process.kill(this._process!.pid!, 'SIGKILL');
+    this.gracefullyExitProcess();
     this._process = undefined;
     this._readBuffer.clear();
   }

src/integration-tests/process-cleanup.test.ts

@@ -5,7 +5,7 @@ import { Client } from "../client/index.js";
 import { StdioClientTransport } from "../client/stdio.js";
 
 describe("Process cleanup", () => {
-  jest.setTimeout(5000); // 5 second timeout
+  jest.setTimeout(10 * 1000); // 10 second timeout
 
   it("server should exit cleanly after closing transport", async () => {
     const server = new Server(
@@ -56,7 +56,7 @@ describe("Process cleanup", () => {
     const pid = transport.pid;
 
     await client.close();
-    await new Promise(resolve => setTimeout(resolve, 1000));
+    await new Promise(resolve => setTimeout(resolve, 5000));
 
     expect(isProcessRunning(pid!)).toBe(false);
   });

src/integration-tests/server-that-hangs.js

@@ -6,7 +6,7 @@ import { StdioServerTransport } from "../../dist/esm/server/stdio.js";
 const transport = new StdioServerTransport();
 
 const server = new McpServer({
-  name: "test-stdio-server",
+  name: "server-that-hangs",
   version: "1.0.0"
 });