Parser Async should reject the Promise when parsing errors are found

[juancoen]

Right now, the promise is fulfilled, returning an invalid API representation and clients must call the errors() method to know if there was an error.

[KonstantinSviridov]

Some users may need even that API representation, which contains errors. That's why we do not reject Promise in this situation.

Is it important for you to have Promise rejected in case of API with errors? If yes, we can introduce a special option for this purpose.

[sichvoge]

Would that change the high-level Parser API?

[KonstantinSviridov]

@sichvoge A little bit. There will be a new field in http://raml-org.github.io/raml-js-parser-2/interfaces/_raml1_wrapped_ast_parsercore_.options.html

[juancoen]

ok, I agree with having an option for rejecting promises on errors, to cover all possible scenarios

[blakeembrey]

What will the rejected promise look like? Rejections should be error instances, but the parser can return multiple errors. An error will errors on a property, or just the first error instance?

[KonstantinSviridov]

@blakeembrey For now it's just an error containing a single message. Do you know some Error subclass which can be passed an object (or array) to constructor (just like we pass strings usually)?

[blakeembrey]

There's nothing formal in JavaScript, but you can just do it yourself. You can also subclass Error if you want to do this in a declarative way (with something like https://github.com/julien-f/js-make-error).

var error = new Error('Invalid RAML')
error.errors = errors // Tada, just document the error type.
return error

[KonstantinSviridov]

Ok, thanks. So, there will be a message Api contains errors. and a complete array of errors.

[KonstantinSviridov]

@blakeembrey It appears that Error subclassing is not available in typescript 1.4 https://github.com/Microsoft/TypeScript/issues/1168.

Seems like it remains to write parser errors to some field of the newly created error.

[blakeembrey]

@KonstantinSviridov I pointed out how you can do it in the comment above.

[KonstantinSviridov]

For loadApi: If the 'rejectOnErrors' option is set to true, ApiLoadingError is thrown for Api which contains errors.

For loadApiAsync: The Promise is rejected with ApiLoadingError if the resulting Api contains errors and the 'rejectOnErrors' option is set to 'true'.

Where ApiLoadingError is http://raml-org.github.io/raml-js-parser-2/interfaces/_raml1_wrapped_ast_parsercore_.apiloadingerror.html