Emphasize that Request extractor goes last #2834
Merged
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Motivation
The error message you get when passing an invalid fn or closure to
from_fn
is rather far removed from the actual error. The itemized list in https://docs.rs/axum/latest/axum/middleware/fn.from_fn.html makes no mention of the limitation thatRequest
must be the last extractor. This is only mentioned in passing in the auth middleware example a way down the page.Solution
Given that putting extractors in the wrong order risks causing a lot of confusion, this PR promotes the ordering requirement to the top of
from_fn
docs so that it is easier to note.