MAGETWO-38417: Table Rates shipping method does not work

Author: Viktor Tymchynskyi

lib/internal/Magento/Framework/Filesystem/Driver/File.php

@@ -9,6 +9,7 @@
 
 use Magento\Framework\Exception\FileSystemException;
 use Magento\Framework\Filesystem\DriverInterface;
+use Magento\Framework\Phrase;
 
 class File implements DriverInterface
 {
@@ -639,6 +640,7 @@ public function fileWrite($resource, $data)
      * @param array $data
      * @param string $delimiter
      * @param string $enclosure
+     * @var $value string|Phrase
      * @return int
      * @throws FileSystemException
      */
@@ -649,6 +651,7 @@ public function filePutCsv($resource, array $data, $delimiter = ',', $enclosure
         * @see https://bugzilla.mozilla.org/show_bug.cgi?id=1054702
         */
         foreach ($data as $key => $value) {
+            $value = (string)$value;
             if (isset($value[0]) && $value[0] === '=') {
                 $data[$key] = ' ' . $value;
             }

lib/internal/Magento/Framework/Filesystem/Io/File.php

@@ -170,6 +170,7 @@ public function streamWrite($str)
      * @param array $row
      * @param string $delimiter
      * @param string $enclosure
+     * @var $value string|Phrase
      * @return int|false The length of the written string or false
      */
     public function streamWriteCsv(array $row, $delimiter = ',', $enclosure = '"')
@@ -182,6 +183,7 @@ public function streamWriteCsv(array $row, $delimiter = ',', $enclosure = '"')
          * @see https://bugzilla.mozilla.org/show_bug.cgi?id=1054702
          */
         foreach ($row as $key => $value) {
+            $value = (string)$value;
             if (isset($value[0]) && $value[0] === '=') {
                 $row[$key] = ' ' . $value;
             }