Two PDF documents can have the “same” JavaScript. The comparison is done byte-wise using the tag <haveSameXMPData />. Whitespaces are ignored.

<testcase name="haveSameJavaScript">
  <assertThat testDocument="test/test.pdf"
              masterDocument="master/master.pdf"
  >
    <haveSameJavaScript />
  </assertThat>
</testcase>

If you want to see the JavaScript code, you can extract it with the utility ExtractJavaScript as described in chapter 9.8: “Extract JavaScript to a Text File”.