Tolerate component routes not starting with '/'

[itowlson]

Fixes #1493.

An alternative solution would be to fail validation if any component route didn't start with '/'. That would be safer in the sense of not committing us to supporting "wrong" manifests, but would risk a user experience of "stupid computer, you know what's wrong so why do you need me to fix it." Happy to switch to that if people prefer.

[fibonacci1729]

LGTM. I think I prefer the magic correction here as opposed to a validation error but I could lean the other way if others feel strongly.

[rylev]

I think I'm ok with us not requiring the user explicitly put a "/" before the route, but there are a few more cases that I think we should think about:

• "..."
• ""

[fibonacci1729]

@rylev I would assume that those 2 cases, given this PR would become "/..." and "/" respectively; these patterns are handled already.

[itowlson]

@fibonacci1729 I think you are right, but maybe those should be rejected: the specification is that wildcards end in /..., and the empty string is more likely to be a mistake than an intentional choice.

(I fear this is the risk of extending tolerance instead of rejecting... we have to figure out how/whether to tolerate the edge cases too, and what consistent behaviour looks like in those situations!)

@rylev Given time zone differences it would be super useful if you could share your preferred behaviour and thoughts on acceptable trade-offs - if we have to iterate on it interactively, the PR is going to be very drawn out, and I don't think these cases are worth keeping on my stack for that long if you see what I mean?

[rylev]

I think we should merge this as is. We can always improve in the future if need be.

[itowlson]

@rylev awesome, thanks!