More and more projects try to follow Semantic Versionning to reduce package versionning nightmare and every dependancy manager implement its own semantic versionner. Composer and NPM for example don’t handle version constraints the same way. It’s hard sometimes to be sure how some library version will behave againts some constraint.
This tiny webapp checks if a given version satifies another given constraint in the NPM world.
But to be honest, this project is also the opportunity to give a shot to ReactJS and its JSX components!