test.js: Compare asset files such as `setup.js` and `site-nav.css`

[yamgent]

• MarkBind Version:
  v1.8.0

We recently updated setup.js to implement new features for our search (see #240). However, we did not update the file inside test/test_site/expected/, so the site test continues to pass even though the actual vs expected setup.js are different now in 305708e.

Fix test.js to compare setup.js so that it fails properly when the content mismatch.

EDIT: Other assets such as site-nav.css also does not have their contents checked, so the test passes as long as the file exist.

EDIT 2: The main logic can be found in test/test_site/testUtil/test.js. The test for now for these files can just be a byte-by-byte comparison (just need to be careful of the line ending difference in Windows and Unix).

[yamgent]

Updated this issue, as we now have even more asset files since the issue was created, but their contents are not being checked currently. Not a big issue now (since it is mostly copied and pasted content, rather than it being generated), but for the sake of completeness it is still worth having.