Question: My unit tests use the `main` entry point in each of my Java classes. I'm using Eclipse. It's been risky to rely on the test results because sometimes I've forgotten to set `-enableassertions` in the JVM arguments. Is there a universal setting that applies to all current and future `Run Configurations`?

Answer: 
To make assertions enabled by default, first go to the Eclipse menu named `Window` because Eclipse is a GUI application so it seems to be an excellent reason to put it in a menu called "Window".

Window > Preferences > Java > Installed JREs

Select the JRE that you use.

Click `Edit`. Add to the `Default VM Arguments` textbox the option `-enableassertions`. Click `Apply` if necessary.

Now, even without enabling assertions in the launch configuration, which seems to be synonymous with run configuration, programs run in Eclipse will have assertions enabled.
Please don't use the Java `assert` in unit tests. 

This kind of assertion can be disabled because it is not intended to be used in unit tests at all. This assert only helps you to ensure some conditions at runtime of your actual code. Unit tests are different and done with special means as like [JUnit](http://junit.org/) 

There are plenty good ressources to learn about proper unit testing, I would like to propose [this](http://www.vogella.com/articles/JUnit/article.html) as a possible starting point.