Actual promisification of client.query

Author: brianc

lib/client.js

@@ -349,19 +349,37 @@ Client.prototype.copyTo = function (text) {
 };
 
 Client.prototype.query = function(config, values, callback) {
-  //can take in strings, config object or query object
-  var query = (typeof config.submit == 'function') ? config :
-     new Query(config, values, callback);
+  var promise;
+  var isQueryable = typeof config.submit == 'function';
+  var query;
+  // if we receive an object with a 'submit' function we delegate
+  // processing to the passed object - this is how pg.Query, QueryStream, and Cursor work
+  if (isQueryable) {
+    query = config;
+  } else {
+    query = new Query(config, values, callback);
+    if (!query.callback) {
+      promise = new global.Promise(function (resolve, reject) {
+        query.on('error', reject);
+        query.on('end', resolve);
+      });
+    }
+  }
   if(this.binary && !query.binary) {
     query.binary = true;
   }
+
+  // TODO - this is a smell
   if(query._result) {
     query._result._getTypeParser = this._types.getTypeParser.bind(this._types);
   }
 
   this.queryQueue.push(query);
   this._pulseQueryQueue();
-  return query;
+
+  // if we were passed a queryable, return it
+  // otherwise return callback/promise result
+  return isQueryable ? query : promise;
 };
 
 Client.prototype.end = function(cb) {