Load Rulesets via JS API

User story. As a developer working with the JS API, I can do reference a custom ruleset (path, url, required from a NPM module), so that I do not need to mess around with the addRules() and addFunctions() interface.

This ticket should deprecate those two methods, but is not responsible for adding custom functions to rulesets. That will be handled in https://github.com/stoplightio/spectral/issues/311

Is your feature request related to a problem? V4.0 made it way easier to work with custom rulesets but working with the TS/JS interface still feels pretty clunky.

Describe the solution you’d like

TBD on the exact interface.

spectral.loadRuleset(‘file://something’)

Additional context

Relates to #365

[philsturgeon]

@marbemac @P0lip hey, it seems like you two were discussing some cool ideas for how the loadRuleset() this ticket suggests could be a helper for a setRuleset(), but there seemed to also be concerns with the actual code being suggested.

It’s getting close to implementation time, and I’d like to make sure this ticket has an implementation that somebody can pick up. Can we punt the setRuleset ideas for now and expose it as a new method later on?

I think we can get away with a simple loadRulesets() function which is doing what loadRules() and loadFunctions() are currently doing? Seem ok?

[P0lip]

Can we punt the setRuleset ideas for now and expose it as a new method later on?

Yeah, I’d vote for holding on with that idea for a while and sticking to the original idea (loadRuleset method only).

I’d like to work on that one, so lack of some details shouldn’t be an issue. 😄 ~Before we start that one, though, we need to have custom functions in place.~

EDIT: or we can add loadRuleset method and wait with removal of addRules and addFunctions until custom functions are implemented.