ivt/assert

PHP assertions library

Example Usage

1. Checking output of functions that return false or null on error

   // good (may silently fail depending on the error handler)
   
   $handle = fopen('/my/file', 'rb');
   $data = fread($handle, 100);
   fclose($handle);

   // better (verbose)
   
   $handle = fopen('/my/file', 'rb');
   if ($handle === false)
       throw new Exception('fopen() failed');
   $data = fread($handle, 100);
   if ($data === false)
       throw new Exception('fread() failed');
   if (fclose($handle) === false)
       throw new Exception('fclose() failed');

   // best (will fail regardless of the error handler)
   
   use IVT\Assert;
   Assert::resource($handle = fopen('/my/file', 'rb'));
   Assert::string($data = fread($handle, 100));
   Assert::true(fclose($handle));

2. Tests

   function humanize_bytes($n) {
       $i = (int)log(max(abs($n), 1), 1000);
       $p = 'KMGTPEZY';
       if ($i == 0)
           return "$n B";
       else
           return number_format($n / pow(1000, $i), 1) . " {$p[$i - 1]}B";
   }
   
   function humanize_bytes_test() {
       Assert::equal(humanize_bytes(1), '1 B');
       Assert::equal(humanize_bytes(-1402), '-1.4 KB');
       // ...
   }

3. Checking invariants

   Assert::int($object->getId()); // Object must have ID

4. etc