General query - what are common test assertions used?

Hi Guillermo and guys, may I check from you what are common assertions that you use in your test automation? Eg check that element contains text, check element exists etc. Crowdsourcing inputs on test assertions for a personal project. This is not an issue, please feel free to close if irrelevant.

In that project I made a wrapper around CasperJS but as CasperJS has no support for visible / headless Chrome, test assertions won't work. Working to address that, for some basic range of assertion scenarios to work with Chrome. Thanks in advance for any advice!