Ordering in the aggregate column level is no longer possible in Postgraphile V5

[erbold-bu]

Summary

PgAggregatesPreset port missing ordering on aggregate fields. This was espacially useful when extending the aggregate functionality with further options like array_agg, where applied order will be applied to the results.

This was our plugin that heavily used it:

export const ARRAY_AGG_SMART_TAG = 'arrayAgg';

export const ArrayAggPlugin: Plugin = (builder) => {
  builder.hook('build', (build) => {
    const { pgSql: sql } = build;

    const arrayAggSpec: AggregateSpec = {
      id: 'arrayAgg',
      humanLabel: 'array aggregation',
      HumanLabel: 'Array aggregation',
      isSuitableType: (pgType) => !!pgType.arrayType,
      sqlAggregateWrap: (sqlFrag) => sql.fragment`coalesce(array_agg(${sqlFrag}), '{}')`,
      pgTypeAndModifierModifier: (pgType) => [pgType.arrayType, null],
      isNonNull: true
    };

    build.pgAggregateSpecs = [...build.pgAggregateSpecs, arrayAggSpec];

    return build;
  });
};

query:
{
  projectsConnection {
    groupedAggregates(groupBy: [TRADES]) {
      keys
      arrayAgg {
        id (orderBy: [ID_ASC])
      }
    }
  }
}

Steps to reproduce

Try to set ordering in the aggregated field. For example:

{
  projectsConnection {
    groupedAggregates(groupBy: [TRADES]) {
      keys
      sum {
        id (orderBy: [ID_ASC])
      }
    }
  }
}

Expected results

It will apply the sorting to the aggregated result. Graphql schema will support ordering on aggregate field.

Actual results

Doesn't support.