Add and improve test coverage

src/Spout/Common/Escaper/CSV.php

@@ -13,6 +13,8 @@ class CSV implements EscaperInterface
     /**
      * Escapes the given string to make it compatible with CSV
      *
+     * @codeCoverageIgnore
+     *
      * @param string $string The string to escape
      * @return string The escaped string
      */
@@ -24,6 +26,8 @@ class CSV implements EscaperInterface
     /**
      * Unescapes the given string to make it compatible with CSV
      *
+     * @codeCoverageIgnore
+     *
      * @param string $string The string to unescape
      * @return string The unescaped string
      */

src/Spout/Common/Helper/GlobalFunctionsHelper.php

@@ -6,6 +6,8 @@ namespace Box\Spout\Common\Helper;
  * Class GlobalFunctionsHelper
  * This class wraps global functions to facilitate testing
  *
+ * @codeCoverageIgnore
+ *
  * @package Box\Spout\Common\Helper
  */
 class GlobalFunctionsHelper

src/Spout/Reader/Helper/XLSX/CellHelper.php

@@ -25,7 +25,7 @@ class CellHelper
     {
         $existingIndexes = array_keys($dataArray);
 
-        $newIndexes = array_fill_keys(range(min($existingIndexes), max($existingIndexes)), $fillValue);
+        $newIndexes = array_fill_keys(range(0, max($existingIndexes)), $fillValue);
         $dataArray += $newIndexes;
 
         ksort($dataArray);

src/Spout/Writer/AbstractWriter.php

@@ -89,6 +89,8 @@ abstract class AbstractWriter implements WriterInterface
      * Inits the writer and opens it to accept data.
      * By using this method, the data will be outputted directly to the browser.
      *
+     * @codeCoverageIgnore
+     *
      * @param  string $outputFileName Name of the output file that will contain the data. If a path is passed in, only the file name will be kept
      * @return \Box\Spout\Writer\AbstractWriter
      * @throws \Box\Spout\Common\Exception\IOException If the writer cannot be opened