Adjustments as per code review.

Author: dereuromark

src/Propel/Common/Config/Loader/FileLoader.php

@@ -125,7 +125,7 @@ protected function checkSupports($ext, $resource)
         }
 
         if (!is_array($ext)) {
-            throw new \InvalidArgumentException('$ext must string or string[]');
+            throw new \InvalidArgumentException('$ext must be string or string[]');
         }
 
         $supported = false;

src/Propel/Generator/Model/Database.php

@@ -492,6 +492,11 @@ public function addTables(array $tables)
         }
     }
 
+    /**
+     * @param \Propel\Generator\Model\Table $table
+     *
+     * @return void
+     */
     public function removeTable(Table $table)
     {
         if ($this->hasTable($table->getName(), true)) {

src/Propel/Runtime/Parser/AbstractParser.php

@@ -44,6 +44,12 @@ abstract public function fromArray($array, $rootKey = 'data');
      */
     abstract public function toArray($data, $rootKey = 'data');
 
+    /**
+     * @param array $data
+     * @param string|null $rootKey
+     *
+     * @return string
+     */
     public function listFromArray($data, $rootKey = 'data')
     {
         return $this->fromArray($data, $rootKey);

src/Propel/Runtime/Parser/CsvParser.php

@@ -36,7 +36,7 @@ class CsvParser extends AbstractParser
      * Converts data from an associative array to CSV.
      *
      * @param array $array Source data to convert
-     * @param string $rootKey Will not be used for converting because csv is flat
+     * @param string|null $rootKey Will not be used for converting because csv is flat
      * @param boolean $isList Whether the input data contains more than one row
      * @param boolean $includeHeading Whether the output should contain a heading line
      *
@@ -62,6 +62,12 @@ public function fromArray($array, $rootKey = null, $isList = false, $includeHead
         return implode($this->lineTerminator, $rows) . $this->lineTerminator;
     }
 
+    /**
+     * @param array $array
+     * @param string|null $rootKey
+     *
+     * @return string
+     */
     public function listFromArray($array, $rootKey = null)
     {
         return $this->fromArray($array, $rootKey, true);

src/Propel/Runtime/Parser/XmlParser.php

@@ -34,12 +34,19 @@ public function fromArray($array, $rootKey = 'data', $charset = null)
         return $rootNode->ownerDocument->saveXML();
     }
 
+    /**
+     * @param array $array
+     * @param string|null $rootKey
+     * @param string|null $charset
+     *
+     * @return string
+     */
     public function listFromArray($array, $rootKey = 'data', $charset = null)
     {
         $rootNode = $this->getRootNode($rootKey);
         $this->arrayToDOM($array, $rootNode, $charset);
 
-        return $rootNode->ownerDocument->saveXML();
+        return (string)$rootNode->ownerDocument->saveXML();
     }
 
     /**