perf(schema): remove unnecessary lookahead in numeric subpath check

Author: vkarpov15

lib/schema.js

@@ -25,6 +25,8 @@ const utils = require('./utils');
 const validateRef = require('./helpers/populate/validateRef');
 const util = require('util');
 
+const hasNumericSubpathRegex = /\.\d+(\.|$)/;
+
 let MongooseTypes;
 
 const queryHooks = require('./helpers/query/applyQueryMiddleware').
@@ -1008,7 +1010,7 @@ Schema.prototype.path = function(path, obj) {
     }
 
     // subpaths?
-    return /\.\d+\.?.*$/.test(path)
+    return hasNumericSubpathRegex.test(path)
       ? getPositionalPath(this, path, cleanPath)
       : undefined;
   }