Anchor on property which uses alias fails validation

[dleavitt]

Schema:

{
  "title": "Field definitions schema!",
  "$schema": "http://json-schema.org/draft-04/schema#",
  "definitions": {
    "field": {
      "type": "object",
      "additionalProperties": false,
      "required": ["label"],
      "properties": {
        "label": { "type": "string" }
      }
    },
    "model": {
      "type": "object",
      "additionalProperties": false,
      "properties": {
        "props": {
          "type": "object",
          "additionalProperties": { "$ref": "#/definitions/field" }
        }
      }
    }
  },
  "type": "object",
  "additionalProperties": { "$ref": "#/definitions/model" }
}

Document:

Named:
  props: &NamedProps
    name:
      label: Name

Timestamped:
  props: &TimestampedProps
    <<: *NamedProps
    ts:
      label: Timestamp

Record:
  props:
    <<: *TimestampedProps # commenting out this line removes the errors
    id:
      label: ID

Looks like it's incorrectly adding a layer of nesting or something?

[JPinkney]

From what I remember the way the merge key works in the code is it basically replaces << with the value so

Timestamped:
  props: &TimestampedProps
    <<: *NamedProps
    ts:
      label: Timestamp

becomes

Timestamped:
  props: &TimestampedProps
    name:
      label: Name
    ts:
      label: Timestamp

and then

Record:
  props:
    <<: *TimestampedProps
    id:
      label: ID

should become

Record:
  props:
    name:
      label: Name
    ts:
      label: Timestamp
    id:
      label: ID

but my guess is somewhere along the lines something is going wrong but then again anchors are the piece of the spec I understand the least

[dleavitt]

Yep, and that's what it does become when parsed. It's just an issue with the schema validation, from what I can tell.

[JPinkney]

I think I've finally figured out what the issue is here. I think only the first merge key is being transformed and not the second one so the representation to the parser is:

Named:
  props: &NamedProps
    name:
      label: Name

Timestamped:
  props: &TimestampedProps
    <<: *NamedProps
    ts:
      label: Timestamp

Record:
  props:
    Timestamped:
      props: &TimestampedProps
        <<: *NamedProps
      ts:
        label: Timestamp
    id:
      label: ID

leading to the issue

[dleavitt]

Anything I can do to help? My yamls are all red :(

[JPinkney]

I haven't been able to look into it but my hunch is that the first merge key is being properly expanded but the second one isn't, leading to the error. The code that does that is here: https://github.com/redhat-developer/yaml-language-server/blob/master/src/languageservice/parser/jsonParser07.ts#L951 if you want to poke around