feat(fastify): supporting fastify route config

[rich-w-lee]

Resolves #11815

PR Checklist

Please check if your PR fulfills the following requirements:

• The commit message follows our guidelines: https://github.com/nestjs/nest/blob/master/CONTRIBUTING.md
• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

PR Type

What kind of change does this PR introduce?

• Bugfix
• Feature
• Code style update (formatting, local variables)
• Refactoring (no functional changes, no api changes)
• Build related changes
• CI related changes
• Other... Please describe:

What is the current behavior?

Issue Number: #11815

What is the new behavior?

Users can use the @RouteConfig() decorator to specify a value for the route config for fastify endpoints

Does this PR introduce a breaking change?

• Yes
• No

Other information

[coveralls]

Pull Request Test Coverage Report for Build f42754e6-8e3c-4930-98b6-09e98c21196b

• 8 of 8 (100.0%) changed or added relevant lines in 3 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.009%) to 92.756%

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Totals
Change from base Build 352ed093-fa75-4b36-b8fb-bac61dbb5219:	0.009%
Covered Lines:	6402
Relevant Lines:	6902

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💛 - Coveralls

[rich-w-lee]

Docs PR: nestjs/docs.nestjs.com#2790

[rich-w-lee]

Note: there wasn't an existing test case for applyCallbackToRouter, so I didn't create a new test for that. Similarly there isn't a test file for fastify-adapter.ts, so I also excluded writing a test for that. If needed, I can add a test case/file and the relevant tests for the new code

[kamilmysliwiec]

Could you create a draft PR to the docs describing this feature? :) A short section just for demonstration purposes would be sufficient

[rich-w-lee]

Could you create a draft PR to the docs describing this feature? :) A short section just for demonstration purposes would be sufficient

Is the change in this PR good or do you want me to elaborate? https://github.com/nestjs/docs.nestjs.com/pull/2790/files

[kamilmysliwiec]

@rich-w-lee ahh I must have missed that PR, apologies! Looks good

[micalevisk]

can we get ride of the any here?

[rich-w-lee]

So I checked in the fastify types, and they don't have a type requirement for it, so I want to check what you prefer instead of any:

1. Using unknown since it's defined by the client
2. Using a generic

[micalevisk]

to me, generic type arg is almost the same as having any in terms of type safety

unknown would be better but cumbersome to maintain

so we can keep any until they release a type for that config.

But we can have a jsdocs on that like this:

/**
 * @param config See {@link https://fastify.dev/docs/latest/Reference/Routes/#config}
 */

[rich-w-lee]

Cool, I can add that in 👍

[kamilmysliwiec]

lgtm