Phpunit图像下载测试

Question

我正在写图像下载服务写在PHP测试用例。我们使用phpunit。如何检查检索到的二进制数据是否为图像？

Answer 1

使用exif_imagetype（请参阅manual）很好，但确实需要您必须将文件放在本地磁盘上。如果你不介意硬编码一些神奇的数字，你可以检查图像类型直接看到testFetchWithoutSaving在下面的例子：

class ImageTest extends PHPUnit_Framework_TestCase 
{ 

/** 
* @see http://stackoverflow.com/a/676975/841830 
*/ 
public function testFetchWithoutSaving(){ 
    $s=file_get_contents("https://www.google.com/images/srpr/logo3w.png"); 
    $this->assertEquals("\x89PNG\x0d\x0a\x1a\x0a",substr($s,0,8)); 

    $s=file_get_contents("https://www.google.com/"); 
    $this->assertEquals("\x89PNG\x0d\x0a\x1a\x0a",substr($s,0,8),"Fails: first 8 bytes are actually '<!doctyp'"); 
    } 

/** 
* @see http://php.net/manual/en/function.exif-imagetype.php 
*/ 
public function testFetchWithTempFile(){ 
    $s=file_get_contents("https://www.google.com/images/srpr/logo3w.png"); 
    $tempFilename="/tmp/phpunit.testImage.testFetchWithTempFile"; 
    file_put_contents($tempFilename,$s); 
    $type=exif_imagetype($tempFilename); 
    unlink($tempFilename); 
    $this->assertTrue($type!==false); //Any recognized image type 
    $this->assertEquals(IMAGETYPE_PNG,$type); //A specific image type 
    } 

}