title: Extensible Assertion library to write successes
body: <p>In the test project I'm working on we have our own class that perform assertions. The main benefit of this class over other assertion libraries is that we use it to write successful assertions to the log, and not only failures. When reading the log, it helps to clearly see that we successfully passed certain critical points in the flow.</p>
  <p>However, this class only supports <code>AreEqual</code>, <code>IsTrue</code>, and few others, and is much less flexible and sophisticated about its messages than <a href="https://docs.nunit.org/articles/nunit/writing-tests/assertions/assertion-models/constraint.html" rel="nofollow noreferrer">NUnit's</a> <code>Assert.That(...)</code>, <a href="https://github.com/shouldly/shouldly" rel="nofollow noreferrer">Shouldly</a> or <a href="https://github.com/fluentassertions/fluentassertions" rel="nofollow noreferrer">FluentAssertions</a>.</p>
  <p>I'm looking for a way to combine the advantages of any of these above (or other) assertion libraries with the ability to write the messages to the log also when successful, but I haven't found a simple way to do that. Any idea how this can be achieved?</p>