feat(platform): add fastify-multipart support for fastify platform

[maronfranc]

add FileInterceptor, FilesInterceptor, AnyFilesInterceptor and
FileFieldsInterceptor for platform-fastify

closes #6894

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
[x] 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?

Currently file upload interceptor is an important feature that is missing in @nestjs/platform-fastify.

Issue Number: N/A

What is the new behavior?

FileInterceptor(s)

Behave as platform-express.

MultipartWrapper

A fastify-multipart wrapper that is responsible to handle file streams and return theses streams result to interceptor.

• It expands fastify-multipart options object adding fileFilter:
  • this filter acts in a similar ways as multer fileFilter
• It is responsable consume fileStream:
  • add size and originalname to file
  • if options.dest is truthy:
    • recursively write folder and then file
    • add path and destination to file object
  • else skip fileStream consumption.
• It handles fastify-multipart req.files() object differently in each method:
  • files() and any() return array of files
  • fileFields() return object with array of files

filterAsyncGenerator

An utils function that filters AsyncGenerator validating options.fileFilter callback conditions before the write iteration begins.

Does this PR introduce a breaking change?

[ ] Yes
[x] No

Other information

I hope this pull request help us find the best solution for platform-fastify file upload interceptor.

[coveralls]

Pull Request Test Coverage Report for Build a3454d6e-4d99-46cf-8ab9-60f563025985

• 239 of 243 (98.35%) changed or added relevant lines in 13 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.2%) to 94.782%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
packages/platform-fastify/multipart/interceptors/any-files.interceptor.ts	13	14	92.86%
packages/platform-fastify/multipart/interceptors/file.interceptor.ts	12	13	92.31%
packages/platform-fastify/multipart/multipart/multipart-wrapper.ts	146	147	99.32%
packages/platform-fastify/multipart/multipart/multipart.utils.ts	11	12	91.67%

Totals
Change from base Build 7b78aa8f-2ae9-4f8e-9a68-151f2b96d8c7:	0.2%
Covered Lines:	5358
Relevant Lines:	5653

---

💛 - Coveralls

[TheNoim]

This would be awesome. Does this support the @UploadedFile() param decorator? Can't find it in the pr.

[maronfranc]

This would be awesome. Does this support the @UploadedFile() param decorator? Can't find it in the pr.

Yes, it does support @UploadedFile() and @UploadedFiles(). Here you can find a sample code for this feature.

[andreferraro]

Hi guys, is there anything new? What should we do to merge this feature?

[m-risto]

Waiting for this so long. We want to move to fastify, this is a blocker. We would be very happy if this is merged.

[kscerbiakas]

@micalevisk Hi, I see you approved PR. Does this mean that PR will get merged with next release?

[micalevisk]

@kscerbiakas

Does this mean that PR will get merged with next release?

Unfortunately, no. I'm not a member of Nestjs's core team. It just means that I liked the proposed solution and tested it myself. It doesn't mean there is no room for improvement, of course.

I do this from time to time with old PRs that I think are good to merge. Just to ping the core team (in some sort) :)

[kscerbiakas]

Any status update on this PR?

[yeongjet]

You may interested: nest-fastify-multer, it works fine in my project.

[vytautas-pranskunas-]

any progress on this?

[DamianGlowala]

@kamilmysliwiec, any chances to include this PR in Nest v9.0.0 release?

[EvilCheetah]

@kamilmysliwiec
Any updates on this issue?

[PringlePot]

Love how there are 2 pull requests fixing this issue, however it is still not possible to implement this on the nestjs standards.

[jackgdll]

Any new updates for this PR? It seems that a lot of people have been asking for this for a long time and it makes sense for better feature parity between the express and fastify platforms.
Is there a problem with the proposed solutions that I'm not aware of?

[SzymonGonet]

Any updates? @kamilmysliwiec

[xegulon]

What's blocking the PR to be merged @kamilmysliwiec @jmcdo29?

[anton-liam]

any update?

@kamilmysliwiec