add test to auto invert text color

Author: SailorMax

tests/PhpWord/Writer/HTML/ElementTest.php

@@ -85,10 +85,10 @@ public function testWriteColSpan()
         $section = $phpWord->addSection();
         $table = $section->addTable();
         $row1 = $table->addRow();
-        $cell11 = $row1->addCell(1000, array('gridSpan' => 2));
+        $cell11 = $row1->addCell(1000, array('gridSpan' => 2, 'bgColor' => '6086B8'));
         $cell11->addText('cell spanning 2 bellow');
         $row2 = $table->addRow();
-        $cell21 = $row2->addCell(500);
+        $cell21 = $row2->addCell(500, array('bgColor' => 'ffffff'));
         $cell21->addText('first cell');
         $cell22 = $row2->addCell(500);
         $cell22->addText('second cell');
@@ -99,6 +99,11 @@ public function testWriteColSpan()
         $this->assertTrue($xpath->query('/html/body/table/tr[1]/td')->length == 1);
         $this->assertEquals('2', $xpath->query('/html/body/table/tr/td[1]')->item(0)->attributes->getNamedItem('colspan')->textContent);
         $this->assertTrue($xpath->query('/html/body/table/tr[2]/td')->length == 2);
+
+        $this->assertEquals('#6086B8', $xpath->query('/html/body/table/tr[1]/td')->item(0)->attributes->getNamedItem('bgcolor')->textContent);
+        $this->assertEquals('#ffffff', $xpath->query('/html/body/table/tr[1]/td')->item(0)->attributes->getNamedItem('color')->textContent);
+        $this->assertEquals('#ffffff', $xpath->query('/html/body/table/tr[2]/td')->item(0)->attributes->getNamedItem('bgcolor')->textContent);
+        $this->assertNull($xpath->query('/html/body/table/tr[2]/td')->item(0)->attributes->getNamedItem('color'));
     }
 
     /**