Ignore Buffer metatypes in validation pipe

[kkoomen]

PR Checklist

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• 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?

[x] 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: N/A

I'm using Stripe in my Nest project and for Stripe callbacks we use a raw body. The code in our codebase is like this: async stripeCallback(@Body() rawBody: Buffer) { ... } and because I've applied a global validation pipe, it's trying to validate a Buffer which should not happen.

What is the new behavior?

It ignores the Buffer type.

Does this PR introduce a breaking change?

[ ] Yes
[x] No

Other information

[coveralls]

Pull Request Test Coverage Report for Build 33b3e109-8464-40cc-a03d-b11b6a461faf

• 1 of 1 (100.0%) changed or added relevant line in 1 file are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 94.818%

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Totals
Change from base Build 989e1c9c-d326-4400-b104-848cb98c7561:	0.0%
Covered Lines:	4922
Relevant Lines:	5191

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💛 - Coveralls

[jmcdo29]

LGTM

[kamilmysliwiec]

Looks great! Thanks. It will be added in the next patch/minor release