add testcase for js minify that produces $jscomp polyfills

with recent closure compiler default input language has changed from ES3 to ES6 produces $jscomp polyfills

tests/MinifyClosureCompilerTest.php

@@ -80,12 +80,22 @@ class MinifyClosureCompilerTest extends TestCase
     {
         $this->assertHasJar();
 
-        $src = file_get_contents(self::$test_files . '/bug-513.js');
+        $src = $this->getDataFile('bug-513.js');
         $minExpected = 'var a=4;';
         $minOutput = Minify_ClosureCompiler::minify($src);
         $this->assertSame($minExpected, $minOutput, 'advanced optimizations');
     }
 
+    public function testOptions()
+    {
+        $this->assertHasJar();
+
+        $src = $this->getDataFile('js/jscomp.polyfill.js');
+        $exp = $this->getDataFile('js/jscomp.polyfill.min.js');
+        $res = Minify_ClosureCompiler::minify($src);
+        $this->assertSame($exp, $res);
+    }
+
     protected function assertHasJar()
     {
         $this->assertNotEmpty(Minify_ClosureCompiler::$jarFile);

tests/TestCase.php

@@ -47,4 +47,23 @@ class TestCase extends PHPUnit_Framework_TestCase
         $this->assertSame($data, $displayed, "$id display");
         $this->assertEquals($data, $cache->fetch($id), "$id fetch");
     }
+
+    /**
+     * Read data file, assert that it exists and is not empty.
+     * As a side effect calls trim() to fight against different Editors that insert or strip final newline.
+     *
+     * @param string $filename
+     * @return string
+     */
+    protected function getDataFile($filename)
+    {
+        $path = self::$test_files . '/' . $filename;
+        $this->assertFileExists($path);
+        $contents = file_get_contents($path);
+        $this->assertNotEmpty($contents);
+        $contents = trim($contents);
+        $this->assertNotEmpty($contents);
+
+        return $contents;
+    }
 }

tests/_test_files/js/jscomp.polyfill.js

@@ -0,0 +1,7 @@
+(function() {
+    /**
+     * @type {string}
+     */
+    var $array = jQuery.find('#div');
+    print($array.find('a'));
+})();

tests/_test_files/js/jscomp.polyfill.min.js

@@ -0,0 +1 @@
+(function(){var a=jQuery.find("#div");print(a.find("a"))})();