matrix-spec-proposals/layouts/partials/json-schema/resolve-allof.html

{{/*

  Resolves the `allOf` keyword (https://swagger.io/specification/v2/#composition-and-inheritance-polymorphism),
  given a JSON schema object.

  `allOf` is used to support a kind of inheritance for JSON schema objects.

  An object can reference a "parent" object using `allOf`, and it then inherits
  its parent's properties. If the same property is present in the child, then
  we use the child's version (the child overrides the parent).

  Of course the parent can itself inherit from *its* parent, so we recurse to
  handle that.

*/}}

{{ $ret := . }}
{{ $original := . }}

{{ $required := .required }}
{{ if not $required }}
    {{ $required := slice }}
{{ end }}

{{ with $ret.allOf }}

    {{ $all_of_values := dict }}

    {{/*
      allOf is always an array
    */}}
    {{ range . }}

        {{ with .required }}
            {{ $required = union $required . }}
        {{ end }}

        {{/*
          With merge, values from the second argument override those from the first argument.
          So this order will accumulate values from allOf items, allowing later ones to override earlier
        */}}
        {{ $all_of_values = merge $all_of_values . }}

    {{ end }}

    {{/*
      Then apply allOf values to the original, but allow the original to override allOf.
    */}}
    {{ $ret = merge $all_of_values $ret }}

    {{/*
      Except that if allOf *itself* contains allOf, we do want to override the original for that field only.
    */}}
    {{ with $all_of_values.allOf }}
        {{ $ret = merge $ret (dict "allOf" . ) }}
    {{ end }}

    {{ with $ret.required }}
        {{ $required = union $required $ret.required }}
    {{ end }}

    {{ $ret = merge $ret (dict "required" $required) }}

{{ end }}

{{/*
  Recurse while we are finding new allOf entries to resolve
*/}}
{{ if ne $ret.allOf $original.allOf }}

    {{ $resolved := partial "json-schema/resolve-allof" $ret }}
    {{ $ret = merge $ret $resolved }}

{{ end }}

{{ return $ret }}