You can call the build directly from console or integrate in your favorite code editor. For information on use and setup, you may read the following article :
Some screenshots of the build integrated in notepad++
the cost of verbosity in our code. We simply compile the code and dutifully get the above warning.
Another quick example
As you can note above, we told the compiler that the shape object is an interface, we then specified that the square object implements the shape interface. We did all this using jsdocs annotations. However in our Square object we didn't provide the implementation
for the draw method. This violates the contract and we are dutifully warned. Note how we've used annotations again and our code does not depend on any third party libraries. It's at a minimum.