unify tests for all compression extensions

src/globals/ext-tests/bz2.php

@@ -2,7 +2,14 @@
 
 declare(strict_types=1);
 
-$str = 'This is bz2 extension test';
-assert(function_exists('bzdecompress'));
 assert(function_exists('bzcompress'));
-assert(bzdecompress(bzcompress($str, 9)) === $str);
+assert(function_exists('bzdecompress'));
+
+$input = str_repeat('The quick brown fox jumps over the lazy dog. ', 10);
+$compressed = bzcompress($input);
+assert(is_string($compressed));
+assert(strlen($compressed) < strlen($input));
+
+$uncompressed = bzdecompress($compressed);
+assert(is_string($uncompressed));
+assert($uncompressed === $input);