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

CDS (Core Data Services) compiler and backends

'use strict';

const { otherSideIsExpandableStructure, resolveArtifactType } = require('./utils');

/**
 * Check the given expression for non-expandable structure usage
 *
 * @param {object} parent Object with the expression as a property
 * @param {string} name Name of the expression property on parent
 * @param {Array} expression Expression to check - .on .xpr .having and .where
 */
function nonexpandableStructuredInExpression( parent, name, expression ) {
  for (let i = 0; i < expression.length; i++) {
    if (expression[i].ref) {
      const { ref } = expression[i];
      // eslint-disable-next-line prefer-const
      let { _art, $scope } = expression[i];
      if (!_art)
        continue;
      const validStructuredElement = otherSideIsExpandableStructure.call(this, expression, i);
      if (_art) {
        _art = resolveArtifactType.call(this, _art);
        // Paths of an expression may end on a structured element only if both operands in the expression end on a structured element
        if ((_art?.elements || _art?.keys && (i === 0 || expression[i - 1] !== 'exists')) && !validStructuredElement && ($scope !== '$self' || $scope === '$self' && ref.length > 1)) { // TODO: Use $self to navigate to struct
          this.error('ref-unexpected-structured',
                     name === 'on' ? [ ...parent.$path, name, i ] : expression[i].$path,
                     { '#': 'std', elemref: { ref } } );
        }
      }
    }
  }
}

module.exports = {
  on: nonexpandableStructuredInExpression,
  having: nonexpandableStructuredInExpression,
  where: nonexpandableStructuredInExpression,
  xpr: nonexpandableStructuredInExpression,
};