Cleanup

node_modules/mongodb/lib/cmap/connection_pool.js

@@ -41,6 +41,7 @@ const VALID_POOL_OPTIONS = new Set([
   'ssl',
   'bson',
   'connectionType',
+  'serverApi',
   'monitorCommands',
   'socketTimeout',
   'credentials',
@@ -95,7 +96,7 @@ const VALID_POOL_OPTIONS = new Set([
 
 function resolveOptions(options, defaults) {
   const newOptions = Array.from(VALID_POOL_OPTIONS).reduce((obj, key) => {
-    if (options.hasOwnProperty(key)) {
+    if (Object.prototype.hasOwnProperty.call(options, key)) {
       obj[key] = options[key];
     }
 
@@ -157,12 +158,13 @@ class ConnectionPool extends EventEmitter {
       waitQueueTimeoutMS:
         typeof options.waitQueueTimeoutMS === 'number' ? options.waitQueueTimeoutMS : 0,
       autoEncrypter: options.autoEncrypter,
-      metadata: options.metadata
+      metadata: options.metadata,
+      useUnifiedTopology: options.useUnifiedTopology
     });
 
     if (options.minSize > options.maxSize) {
       throw new TypeError(
-        'Connection pool minimum size must not be greater than maxiumum pool size'
+        'Connection pool minimum size must not be greater than maximum pool size'
       );
     }
 
@@ -218,7 +220,6 @@ class ConnectionPool extends EventEmitter {
       return;
     }
 
-    // add this request to the wait queue
     const waitQueueMember = { callback };
 
     const pool = this;
@@ -233,11 +234,8 @@ class ConnectionPool extends EventEmitter {
       }, waitQueueTimeoutMS);
     }
 
-    // place the member at the end of the wait queue
     this[kWaitQueue].push(waitQueueMember);
-
-    // process the wait queue
-    processWaitQueue(this);
+    process.nextTick(() => processWaitQueue(this));
   }
 
   /**
@@ -250,10 +248,8 @@ class ConnectionPool extends EventEmitter {
     const stale = connectionIsStale(this, connection);
     const willDestroy = !!(poolClosed || stale || connection.closed);
 
-    // Properly adjust state of connection
     if (!willDestroy) {
       connection.markAvailable();
-
       this[kConnections].push(connection);
     }
 
@@ -264,7 +260,7 @@ class ConnectionPool extends EventEmitter {
       destroyConnection(this, connection, reason);
     }
 
-    processWaitQueue(this);
+    process.nextTick(() => processWaitQueue(this));
   }
 
   /**
@@ -434,7 +430,7 @@ function createConnection(pool, callback) {
 
     // otherwise add it to the pool for later acquisition, and try to process the wait queue
     pool[kConnections].push(connection);
-    processWaitQueue(pool);
+    process.nextTick(() => processWaitQueue(pool));
   });
 }
 
@@ -483,7 +479,7 @@ function processWaitQueue(pool) {
   if (pool.waitQueueSize && (maxPoolSize <= 0 || pool.totalConnectionCount < maxPoolSize)) {
     createConnection(pool, (err, connection) => {
       const waitQueueMember = pool[kWaitQueue].shift();
-      if (waitQueueMember == null) {
+      if (waitQueueMember == null || waitQueueMember[kCancelled]) {
         if (err == null) {
           pool[kConnections].push(connection);
         }
@@ -491,10 +487,6 @@ function processWaitQueue(pool) {
         return;
       }
 
-      if (waitQueueMember[kCancelled]) {
-        return;
-      }
-
       if (err) {
         pool.emit('connectionCheckOutFailed', new ConnectionCheckOutFailedEvent(pool, err));
       } else {