Use switch-style of arg validation to fix lint errors

Author: cjbj

lib/pool.js

@@ -136,10 +136,20 @@ function getConnection(a1, a2) {
   var timeoutHandle;
   var timerIdx;
   var poolMax;
-  var getConnectionCb = arguments[arguments.length - 1];
+  var getConnectionCb;
   var options = {};
 
   nodbUtil.assert(arguments.length >= 1 && arguments.length <= 2, 'NJS-009');
+  switch (arguments.length) {
+    case 1:
+      getConnectionCb = a1;
+      break;
+    case 2:
+      nodbUtil.assert(nodbUtil.isObject(a1), 'NJS-006', 1);
+      options = a1;
+      getConnectionCb = a2;
+      break;
+  }
   nodbUtil.assert(typeof getConnectionCb === 'function', 'NJS-006', arguments.length);
 
   if (self.status === self._oracledb.POOL_STATUS_DRAINING) {  // closing soon
@@ -150,12 +160,6 @@ function getConnection(a1, a2) {
     return;
   }
 
-  // Optional JSON parameter
-  if (arguments.length > 1 ) {
-    options = arguments[0];
-    nodbUtil.assert(nodbUtil.isObject(options), 'NJS-006', 1 );
-  }
-
   if (self._enableStats) {
     self._totalConnectionRequests += 1;
   }