refactor(server): add shutdown idempotency guard and test teardown blocks

docs/plans/2026-09-06-mcp-server-plan.md

@@ -1,3 +1,4 @@
+
 # MCP Stdio Server Assembly & Integration Implementation Plan
 
 > **For agentic workers:** REQUIRED SUB-SKILL: Use superpowers:subagent-driven-development (recommended) or superpowers:executing-plans to implement this plan task-by-task. Steps use checkbox (`- [ ]`) syntax for tracking.

src/index.ts

@@ -12,7 +12,10 @@ async function main(): Promise<void> {
     const mcpServer = createServer(config);
 
     // Bind graceful termination
+    let isShuttingDown = false;
     const shutdown = async () => {
+      if (isShuttingDown) return;
+      isShuttingDown = true;
       console.error("\n[openproject-mcp] Received termination signal, shutting down...");
       await mcpServer.stop();
       process.exit(0);

tests/mcp-server.test.ts

@@ -199,6 +199,7 @@ describe("End-to-End Live Tool Calling over MCP Client", () => {
     const client = new Client({ name: "test-runner", version: "1" });
     await client.connect(clientTransport);
 
+    try {
       // Call openproject_list_projects
       const projRes = (await client.callTool({
         name: "openproject_list_projects",
@@ -222,9 +223,10 @@ describe("End-to-End Live Tool Calling over MCP Client", () => {
       expect(wpRes.isError).toBeFalsy();
       const wpData = JSON.parse(wpRes.content[0]?.text ?? "{}");
       expect(wpData.id).toBe(38);
-
+    } finally {
       await client.close();
       await mcpServer.stop();
+    }
   });
 
   test("tool error propagation returns isError: true without crashing client", async () => {
@@ -235,6 +237,7 @@ describe("End-to-End Live Tool Calling over MCP Client", () => {
     const client = new Client({ name: "test-runner", version: "1" });
     await client.connect(clientTransport);
 
+    try {
       const errRes = (await client.callTool({
         name: "openproject_get_project",
         arguments: { projectId: 999999 },
@@ -244,9 +247,10 @@ describe("End-to-End Live Tool Calling over MCP Client", () => {
       };
       expect(errRes.isError).toBe(true);
       expect(errRes.content[0]?.text).toContain("OPENPROJECT_NOT_FOUND");
-
+    } finally {
       await client.close();
       await mcpServer.stop();
+    }
   });
 });