feat: add contentType option

[Fdawgs]

This PR adds the ability to disable the Content-Type response header via the contentType option.

Whilst the automatic setting of the Content-Type response header is great, it's not always right for some edge cases, such as for vendor-specific or proprietary extensions.

Likewise, the charset is hardcoded to utf-8 for text/plain, text/html and application/json files; these types can support more than just utf-8 character encoded content so it'd be nice to get around that.

Related to fastify/fastify-static#480.

Checklist

• run npm run test and npm run benchmark
• tests and/or benchmarks are included
• documentation is changed or added
• commit message and code follows the Developer's Certification of Origin
  and the Code of conduct

Copilot reviewed 4 out of 4 changed files in this pull request and generated no suggestions.

[Fdawgs]

Should I just add a new test block to the types tests or add contentType: true to one of the existing ones?

[gurgunday]

LGTM except the type test

I think you can add it to an existing test as well, both should be fine

[dancastillo]

LGTM

[Fdawgs]

Any thoughts on this @climba03003? I know you've worked a lot on the rewrite of this module so didn't want to go ahead and merge without your input!

[climba03003]

I am thinking the needs of disable option.
Since this library is just provides whatever information the consumer needs, it is up to the consumer to decide if he / she want what header.
It is a bit overkill provide an option to disable feature. (The function here is just a giant map lookup. Should not be costly.)

[Fdawgs]

I am thinking the needs of disable option. Since this library is just provides whatever information the consumer needs, it is up to the consumer to decide if he / she want what header. It is a bit overkill provide an option to disable feature. (The function here is just a giant map lookup. Should not be costly.)

So... is that a tentative approval? 😆

[climba03003]

Yes, but I do believe @fastify/static require it's own fix.