tornadoweb
Optional request fields that should always have values
HTTPServerRequest has e.g. method and uri typed as Optional[str]. In production, I cannot image those being unavailable, so I suppose it came to be this way for testing purposes. Meanwhile there are modern tools/techniques to generate/pass stub data. Does this design decision still make sense then? I find myself writing things like self.redirect(self.request.uri or '') just to get rid of squiggly lines.
When I introduced type annotations, in a lot of places I didn't go any farther than required to get mypy to pass on Tornado itself. So you're right that these really shouldn't be optional. The code is actually a bit of a mess now (comments say that uri is the only required argument, but we don't actually use it outside of tests. We use start_line instead).
There aren't that many test cases where we construct HTTPServerRequests by hand, so we should update those to pass non-None values for method and uri (and probably other fields) and then fix the type annotations to reflect what's really optional and what's always going to be there.
