feat(ipcclient): Add clientOnly mode to prevent clients from auto-starting servers and improve registration/reconnect behavior

test/test.improvements.ts

@@ -192,6 +192,61 @@ tap.test('Client retry should work with delayed server', async () => {
   await server.stop();
 });
 
+// Test 7: clientOnly prevents client from auto-starting a server
+tap.test('clientOnly should prevent auto-start and fail fast', async () => {
+  const uniqueSocketPath = path.join(os.tmpdir(), `smartipc-clientonly-${Date.now()}.sock`);
+
+  const client = smartipc.SmartIpc.createClient({
+    id: 'clientonly-test',
+    socketPath: uniqueSocketPath,
+    clientId: 'co-client-1',
+    clientOnly: true,
+    connectRetry: { enabled: false }
+  });
+
+  let failed = false;
+  try {
+    await client.connect();
+  } catch (err: any) {
+    failed = true;
+    expect(err.message).toContain('clientOnly prevents auto-start');
+  }
+  expect(failed).toBeTrue();
+  // Ensure no server-side socket was created
+  expect(fs.existsSync(uniqueSocketPath)).toBeFalse();
+});
+
+// Test 8: env SMARTIPC_CLIENT_ONLY enforces clientOnly behavior
+tap.test('SMARTIPC_CLIENT_ONLY=1 should enforce clientOnly', async () => {
+  const uniqueSocketPath = path.join(os.tmpdir(), `smartipc-clientonly-env-${Date.now()}.sock`);
+  const prev = process.env.SMARTIPC_CLIENT_ONLY;
+  process.env.SMARTIPC_CLIENT_ONLY = '1';
+
+  const client = smartipc.SmartIpc.createClient({
+    id: 'clientonly-test-env',
+    socketPath: uniqueSocketPath,
+    clientId: 'co-client-2',
+    connectRetry: { enabled: false }
+  });
+
+  let failed = false;
+  try {
+    await client.connect();
+  } catch (err: any) {
+    failed = true;
+    expect(err.message).toContain('clientOnly prevents auto-start');
+  }
+  expect(failed).toBeTrue();
+  expect(fs.existsSync(uniqueSocketPath)).toBeFalse();
+
+  // restore env
+  if (prev === undefined) {
+    delete process.env.SMARTIPC_CLIENT_ONLY;
+  } else {
+    process.env.SMARTIPC_CLIENT_ONLY = prev;
+  }
+});
+
 // Cleanup
 tap.test('Cleanup test socket', async () => {
   try {
@@ -201,4 +256,4 @@ tap.test('Cleanup test socket', async () => {
   }
 });
 
-export default tap.start();
+export default tap.start();