I normally do C++, but started doing some Typescript (Javascript) the other day. Like Java, this doesn't make external implementation easy. I found myself usin

I normally do C++, but started doing some Typescript (Javascript) the other day. Like Java, this doesn't make external implementation easy. I found myself using a pattern of declaring a one-off interface for complex classes and then implementing it in the real class. I'm still undecided when/if this is a useful thing to do.