Shared strings table without uniqueCount and count should work (#269)

Use file based strategy in this case

tests/Spout/Reader/XLSX/Helper/SharedStringsCaching/CachingStrategyFactoryTest.php

@@ -15,6 +15,7 @@ class CachingStrategyFactoryTest extends \PHPUnit_Framework_TestCase
     public function dataProviderForTestGetBestCachingStrategy()
     {
         return [
+            [null, -1, 'FileBasedStrategy'],
             [CachingStrategyFactory::MAX_NUM_STRINGS_PER_TEMP_FILE, -1, 'FileBasedStrategy'],
             [CachingStrategyFactory::MAX_NUM_STRINGS_PER_TEMP_FILE + 10, -1, 'FileBasedStrategy'],
             [CachingStrategyFactory::MAX_NUM_STRINGS_PER_TEMP_FILE - 10, -1, 'InMemoryStrategy'],
@@ -27,7 +28,7 @@ class CachingStrategyFactoryTest extends \PHPUnit_Framework_TestCase
     /**
      * @dataProvider dataProviderForTestGetBestCachingStrategy
      *
-     * @param int $sharedStringsUniqueCount
+     * @param int|null $sharedStringsUniqueCount
      * @param int $memoryLimitInKB
      * @param string $expectedStrategyClassName
      * @return void

tests/Spout/Reader/XLSX/ReaderTest.php

@@ -126,6 +126,20 @@ class ReaderTest extends \PHPUnit_Framework_TestCase
         $this->assertEquals($expectedRows, $allRows);
     }
 
+    /**
+     * @return void
+     */
+    public function testReadShouldSupportSheetWithSharedStringsMissingUniqueCountAndCountAttributes()
+    {
+        $allRows = $this->getAllRowsForFile('one_sheet_with_shared_strings_missing_unique_count_and_count.xlsx');
+
+        $expectedRows = [
+            ['s1--A1', 's1--B1'],
+            ['s1--A2', 's1--B2'],
+        ];
+        $this->assertEquals($expectedRows, $allRows);
+    }
+
     /**
      * @return void
      */