fix(kill): should not try to open a connection to a not running ReplSet (#811)

Author: arthursimas1

packages/mongodb-memory-server-core/src/util/MongoInstance.ts

@@ -9,6 +9,7 @@ import {
   killProcess,
   ManagerBase,
   checkBinaryPermissions,
+  isAlive,
 } from './utils';
 import { lt } from 'semver';
 import { EventEmitter } from 'events';
@@ -423,7 +424,7 @@ export class MongoInstance extends EventEmitter implements ManagerBase {
     // wrap the actual stop in a promise, so it can be awaited in multiple calls
     // for example a instanceError while stop is already running would cause another stop
     this.stopPromise = (async () => {
-      if (!isNullOrUndefined(this.mongodProcess)) {
+      if (!isNullOrUndefined(this.mongodProcess) && isAlive(this.mongodProcess.pid)) {
         // try to run "shutdown" before running "killProcess" (gracefull "SIGINT")
         // using this, otherwise on windows nodejs will handle "SIGINT" & "SIGTERM" & "SIGKILL" the same (instant exit)
         if (this.isReplSet) {

packages/mongodb-memory-server-core/src/util/__tests__/MongoInstance.test.ts

@@ -10,6 +10,7 @@ import {
   UnexpectedCloseError,
 } from '../errors';
 import { assertIsError } from '../../__tests__/testUtils/test_utils';
+import { MongoClient } from 'mongodb';
 
 jest.setTimeout(100000); // 10s
 
@@ -278,6 +279,25 @@ describe('MongodbInstance', () => {
     expect(dbUtil.killProcess).not.toBeCalled();
   });
 
+  it('"kill" should not try to open a connection to a not running ReplSet', async () => {
+    const gotPort = await getFreePort();
+    const mongod = new MongodbInstance({
+      instance: {
+        replSet: 'testset',
+        ip: '127.0.0.1',
+        port: gotPort,
+        dbPath: tmpDir,
+      },
+    });
+    await mongod.start();
+    jest.spyOn(MongoClient, 'connect');
+    process.kill(mongod.mongodProcess!.pid, 'SIGKILL');
+    await new Promise<void>((resolve) => setTimeout(resolve, 100));
+    await mongod.stop();
+
+    expect(MongoClient.connect).not.toBeCalled();
+  });
+
   it('"_launchMongod" should throw an error if "mongodProcess.pid" is undefined', () => {
     const mongod = new MongodbInstance({ instance: { port: 0, dbPath: '' } }); // dummy values - they shouldnt matter
     const mockBinary = '/tmp/thisShouldNotExist';