Description

1. Aggregation Name Field Error

Problem: The schema incorrectly modeled aggregation names as object properties with a name field.

Before:

Aggregation:
  properties:
    name:
      type: string
    # ... other properties

Reality: Aggregation names are JSON keys, not object properties:

{
  "my_agg_name": {     // ← Name is the key
    "terms": {...}
  }
}

Fix: Removed the unnamed name field from the Aggregation schema. The name is represented by the key in the parent object's additionalProperties or propertyNames.

Reference: Java implementation uses builder.startObject(name) in AbstractAggregationBuilder, not builder.field("name", name).

2. ValueType Enum Mismatch

Problem: The ValueType enum included geo_point and range which cannot be parsed from REST API requests.

Evidence: In ValueType.java, the lenientParse() method only accepts:

• "string", "long", "integer", "short", "double", "float", "date", "ip", "boolean", "unsigned_long", "number", "numeric"
• Does NOT include "geo_point" or "range"

These types are internal-only (used in Java code) but cannot be specified by API users.

Fix: Removed geo_point and range from the ValueType enum.

3. BucketAggregationBase oneOf Validation Bug

Problem: Aggregations without sub-aggregations failed validation with error: "MUST contain the missing properties: adjacency_matrix, auto_date_histogram, avg..."

Root Cause: The oneOf constraint had only 2 branches without proper required fields:

oneOf:
  - properties: {aggregations: ...}  # No required
  - properties: {aggs: ...}          # No required

4. Filter Aggregation Sub-aggregation Support

Problem: The filter aggregation was defined as a simple property without extending BucketAggregationBase, preventing it from having sub-aggregations.

Before:

- properties:
    filter:
      $ref: '_common.query_dsl.yaml#/components/schemas/QueryContainer'
  required: [filter]
  unevaluatedProperties: true

This only allowed the filter property. Using sub-aggregations like this would fail:

{
  "moviesWithHiddenCost": {
    "filter": {"term": {"cost_hidden": true}},
    "aggs": {                          // <-- Not allowed
      "numOfDirectors": {
        "cardinality": {"field": "director_id"}
      }
    }
  }
}

Fix: Changed to allOf that extends BucketAggregationBase:

- allOf:
    - $ref: '#/components/schemas/BucketAggregationBase'  # ← Provides sub-agg support
    - type: object
      properties:
        filter:
          $ref: '_common.query_dsl.yaml#/components/schemas/QueryContainer'
      required: [filter]
  x-protobuf-excluded: true

5. Request/Response Alias Handling

Context: Both aggs and aggregations are accepted in requests, but only aggregations appears in responses.

Fix: Added x-protobuf-excluded: true to the aggs property to exclude it from protobuf generation, since it's just an alias that only makes sense on the REST but not protobuf side.

Issues Resolved

List any issues this PR will resolve, e.g. Closes [...].

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