Skip validation of content-type by TypedBody if body is empty

[kelchm]

Feature Request

In some cases I'd like to be able to make the body of a request optional. This seems to work as expected with @TypedBody, with the exception of it enforcing a check for a Content-Type of application/json:

nestia/packages/core/src/decorators/TypedBody.ts

Lines 38 to 41 in 807474a

	if (isApplicationJson(request.headers["content-type"]) === false)
	throw new BadRequestException(
	`Request body type is not "application/json".`,
	);

I would argue that specifically in the case of a request with no body, there should be no expectation of a Content-Type header and therefore we should bypass this check. It would then be up to the validator to make a determination of whether this empty body is permissible.

[samchon]

You are meaning that when the request body parameter type is optional, right?