Ranked in these QuestionsQuestion Ranking
Pro Allows screenshots (either the full page or parts of it) if performing UI testing
There are times where you don't want to open up a browser for screencaps, that is where CasperJS comes to use, it can render the page using its own rendering engine and take and save a screenshot for you, all via the commandline
Pro Easy to understand
Since all webdevs know JS, the start-up time of learning the framework will be reduced to zero, as your team can be productive from day one.
Pro Easily integrates with other applications
Due to the simplicity of the framework, not only other libraries can be built with it, but it can be integrated with any web application as well.
Pro Works great with modern node.js features
Pro Runs a real browser
Unlike the other options here, this is a real browser, just without the GUI parts. This means the quality of the test is much higher, and lets you do things like save to PDF or images.
Pro Actively developed and promoted by Google
Pro Complete API for Chromium included
Chromium tests depend on the same API that Puppeteer gives you access to, so all the features are included
Con Not for unit testing but rather UI testing
These are two extremely different concepts. CasperJS should be removed from this list
Con Cannot guarantee 100% accurate Webkit-based browser screenshots
QtWebKit is the rendering engine used by CasperJS. Keep in mind this is NOT the same rendering engine as Chrome; hence, if you want to be 100% sure of the results, you must run a Webkit browser (such as Chrome) yourself.
Con Not good for Cross Browser Tests
Since it only tests via Chromium, it won't help you test inconsistencies between browsers like Edge or Safari. There are projects to get around this, but they aren't mature.