filter out non-files

Non-files, such as eval'd code, can cause code coverage to fail. Test whether a filename is likely to be a file (with Filter::isFile)
when checking whether a file should be filtered from code coverage

Author: brettmc

src/CodeCoverage/Filter.php

@@ -272,6 +272,10 @@ public function isFile($filename)
      */
     public function isFiltered($filename)
     {
+        if(!$this->isFile($filename))
+        {
+            return true;
+        }
         $filename = realpath($filename);
 
         if (!empty($this->whitelistedFiles)) {

tests/PHP/CodeCoverage/FilterTest.php

@@ -300,4 +300,16 @@ public function testNotWhitelistedFileIsFiltered()
         $this->filter->addFileToWhitelist($this->files[0]);
         $this->asserttrue($this->filter->isFiltered($this->files[1]));
     }
+
+    /**
+     * @covers PHP_CodeCoverage_Filter::isFiltered
+     */
+    public function testNonFilesAreFiltered()
+    {
+        $this->asserttrue($this->filter->isFiltered('eval()\'d code'));
+        $this->asserttrue($this->filter->isFiltered('runtime-created function'));
+        $this->asserttrue($this->filter->isFiltered('assert code'));
+        $this->asserttrue($this->filter->isFiltered('regexp code'));
+        $this->assertfalse($this->filter->isFiltered('filename'));
+    }
 }