format and ruleset: AsyncAPI

[philsturgeon]

User story.
As an AsyncAPI, I will get validation and a reasonable set of default opinions when working with AsyncAPI files.

Is your feature request related to a problem?
Right now spectral doesn't know what AsyncAPI is. It'll recognize $ref'ed schema files, but not the main thing, so I cannot write rules for channel names, etc.

Describe the solution you'd like

A ruleset based on OpenAPI (started here apisyouwonthate/style-guide#4).

AsyncAPI is important enough that it should be another core ruleset, not done over at openapi-contrib. We will almost certainly split rulesets out into their own NPM modules in the future, but for now, let's get this one in the core.

[nulltoken]

@philsturgeon Started to work on this.

[derberg]

Hey, I'm working on this issue in AsyncAPI generator asyncapi/generator#182 and it triggered an interesting discussion on slack, on how to treat the case of servers.url that has variables defined, but with whitespaces. In theory, user can create such a variable as { port} because technically he could get:

variables:
  " port":
       default: 80

The thing is, it is possible, but the probability is very low.

I think that for you it would be a nice use case, for a nifty rule, that spec owner gets a:

• warning that the variable that he has in theurl has whitespaces
• error that the variable defined in the url is not declared in variables object

just letting you know in case you are looking for ideas ;)