refactor: simplify the escapeIdentifier logic

Author: gajus

Diff for: lib/client.js

@@ -305,20 +305,7 @@ Client.prototype.getTypeParser = function (oid, format) {
 
 // Ported from PostgreSQL 9.2.4 source code in src/interfaces/libpq/fe-exec.c
 Client.prototype.escapeIdentifier = function (str) {
-  var escaped = '"'
-
-  for (var i = 0; i < str.length; i++) {
-    var c = str[i]
-    if (c === '"') {
-      escaped += c + c
-    } else {
-      escaped += c
-    }
-  }
-
-  escaped += '"'
-
-  return escaped
+  return '"' + str.replace(/"/g, '""') + '"'
 }
 
 // Ported from PostgreSQL 9.2.4 source code in src/interfaces/libpq/fe-exec.c