A lot of people here are right, the right way is with an NFA. I just want to add that the solution is not even hard, you can do it with string concatenation and capture groups using regexps. Regexps are NFAs, and are highly optimized C code in just about every JS engine.
If I have the routes /foo/bar and /foo/bar/(\d+) I can generate the regexp ((^\/foo\/bar$)|(^\/foo\/bar\/\d+$))
I'm not at all surprised, the quality of software in node is pretty low, I've seen numerous issues in node libs being just as boneheaded. I swear, the fact that the express devs overlooked a key optimization is crazy. Rails, by way of example, uses the Journey engine to solve this problem (https://github.com/rails/journey)
If I have the routes /foo/bar and /foo/bar/(\d+) I can generate the regexp ((^\/foo\/bar$)|(^\/foo\/bar\/\d+$))
I'm not at all surprised, the quality of software in node is pretty low, I've seen numerous issues in node libs being just as boneheaded. I swear, the fact that the express devs overlooked a key optimization is crazy. Rails, by way of example, uses the Journey engine to solve this problem (https://github.com/rails/journey)