Need full documentation

I have only little experience with Postman and newman, and I need to create a custom reporter for newman because I need a JSON report different from what can be generated with existing reporters.
But I’m getting crazy understanding how to access all available report data, I’m using existing reporters to replicate and extend what they do, but I would really need a complete reference.
Where can I find the full documentation for the object and its children?
For example I can see that run.failures is an array of Error type objects, but what attributes do they expose? E.g. I see a reporter is accessing failure.error.test but I cannot find this documented anywhere. Or what information can be read from run.executions?

Maybe I’m just searching in the wrong place.
Thank you in advance.