[mcollina]

Share a route-level rate-limit store between a GET route and the HEAD routes Fastify generates from it. Explicit HEAD routes and routes with distinct constraints retain independent stores, including prefixed trailing-slash aliases and Redis or custom stores.

[gurgunday]

This looks fine

but it's about 200 lines of guessing which HEAD routes fastify generated by matching URL, prefix and constraints

it would be simpler if fastify core flagged its generated HEAD routes in onRoute since it already tracks them internally

[mcollina]

Opened fastify/fastify#7155 to expose isGeneratedHeadRoute in onRoute. Once that lands in a Fastify release, this PR can use the authoritative flag instead of inferring generated routes from route metadata.