Test: put csv callback

package.xml

@@ -225,6 +225,7 @@
    <file md5sum="98f47ea5e8aab04af809a1707a1f1476" name="tests/sheet_checkout.phpt" role="test" />
    <file md5sum="5811dd930d7b0f916c662139ff1053d4" name="tests/string_from_column_index.phpt" role="test" />
    <file md5sum="42b26f050d9291509d6f583ef43ebde9" name="tests/xlsx_to_csv.phpt" role="test" />
+   <file name="tests/xlsx_to_csv_callback.phpt" role="test" />
    <file md5sum="a9af7f4ca385ba41b008b50ac67f8e96" name="tests/zoom.phpt" role="test" />
    <file md5sum="f4a2d1a28ad1bf782502d698de0b1907" name="tests/include/skipif.inc" role="test" />
    <file md5sum="bb4256831dfd81f951bd6f4afbe1719f" name="CREDITS" role="doc" />

tests/xlsx_to_csv_callback.phpt

@@ -0,0 +1,58 @@
+--TEST--
+Check for vtiful presence
+--SKIPIF--
+<?php
+require __DIR__ . '/include/skipif.inc';
+skip_disable_reader();
+?>
+--FILE--
+<?php
+$config   = ['path' => './tests'];
+$excel    = new \Vtiful\Kernel\Excel($config);
+$filePath = $excel->fileName('tutorial.xlsx', 'TestSheet1')
+    ->header(['Item', 'Cost'])
+    ->data([
+        ['Item_1', 'Cost_1', 10, 10.9999995],
+    ])
+    ->output();
+
+$fp = fopen('./tests/file.csv', 'w');
+
+$csvResult = $excel->openFile('tutorial.xlsx')
+    ->openSheet()
+    ->putCSVCallback(function($row){
+        return $row;
+    }, $fp);
+
+fclose($fp);
+
+var_dump($csvResult);
+
+$fp = fopen('./tests/file.csv', 'r');
+
+var_dump(fgetcsv($fp));
+var_dump(fgetcsv($fp));
+?>
+--CLEAN--
+<?php
+@unlink(__DIR__ . '/tutorial.xlsx');
+@unlink(__DIR__ . '/file.csv');
+?>
+--EXPECT--
+bool(true)
+array(2) {
+  [0]=>
+  string(4) "Item"
+  [1]=>
+  string(4) "Cost"
+}
+array(4) {
+  [0]=>
+  string(6) "Item_1"
+  [1]=>
+  string(6) "Cost_1"
+  [2]=>
+  string(2) "10"
+  [3]=>
+  string(10) "10.9999995"
+}