@sap/cds-compiler/lib/checks/existsInForbiddenPlaces.js

CDS (Core Data Services) compiler and backends

'use strict';

const { applyTransformationsOnNonDictionary } = require('../model/csnUtils');

/**
 * Checks a query for forbidden usage of the `exists` predicate within `groupBy` and `orderBy`.
 *
 * @param {object} query
 * @param {string} prop - either groupBy or orderBy.
 * @param {object[]} _tokenStream the value of query[prop]
 * @param {object|Array} pathToClause - Path to respective groupBy/orderBy clause in the CSN.
 * @this {object} The calling context must provide an `error` function.
 */
function existsInForbiddenPlaces( query, prop, _tokenStream, pathToClause ) {
  applyTransformationsOnNonDictionary(query, prop, {
    ref: (_parent, _prop, _ref, pathToError, tokenStream, index) => {
      if (tokenStream[index - 1] === 'exists') {
        // the path should point to the exists
        const pathToExists = pathToError.with(-1, index - 1);
        this.error('query-unexpected-exists', pathToExists, {
          '#': prop,
          prop: 'exists',
        });
      }
    },
  }, null, pathToClause);
}

module.exports = {
  groupBy: existsInForbiddenPlaces,
  orderBy: existsInForbiddenPlaces,
};