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

CDS (Core Data Services) compiler and backends

'use strict';

const { setProp, forEachValue } = require('../utils/objectUtils');
const { featureFlags } = require('../transform/featureFlags');
const { isSqlService, isDummyService, isDataProductProductionService } = require('../transform/db/processSqlServices');

/**
 * Set a feature flag on the CSN model.
 *
 * @param {CSN.Model} csn CSN model to set flag on
 * @param {string} flag Flag name to set
 */
function setFeatureFlag( csn, flag ) {
  if (!csn.meta)
    setProp(csn, 'meta', {});
  if (!csn.meta[featureFlags])
    csn.meta[featureFlags] = {};

  csn.meta[featureFlags][flag] = true;
}

/**
 * Get a function that detects and sets feature flags for expand/inline columns in a query.
 *
 * @param {CSN.Model} csn CSN model to set flags on
 * @returns {Function} Function to call per query
 */
function getQueryFeatureFlagSetter( csn ) {
  return function setQueryFeatureFlags(query) {
    const queryProp = query.SELECT ? 'SELECT' : 'projection';
    query[queryProp]?.columns?.forEach((column) => {
      if (column.expand || column.inline)
        setFeatureFlag(csn, '$expandInline');
    });
  };
}

/**
 * Get a function that detects and sets feature flags for entity/service definitions.
 * That are calculated elements and SQL services.
 *
 * @param {CSN.Model} csn CSN model to set flags on
 * @param {CSN.Options} options Compiler options
 * @returns {Function} Function to call per definition
 */
function getDefinitionFeatureFlagSetter( csn, options ) {
  return function setDefinitionFeatureFlags(def) {
    if (def.kind === 'entity' && def.elements) {
      forEachValue(def.elements, (element) => {
        if (element.value)
          setFeatureFlag(csn, '$calculatedElements');
      });
    }
    else if (def.kind === 'service') {
      if (isSqlService(def))
        setFeatureFlag(csn, '$sqlService');
      if (isDummyService(def, options))
        setFeatureFlag(csn, '$dummyService');
      if (isDataProductProductionService(def))
        setFeatureFlag(csn, '$dataProductService');
    }
  };
}

// Export factory functions that create bound feature flag setters for use in transformation loops
module.exports = {
  getQueryFeatureFlagSetter,
  getDefinitionFeatureFlagSetter,
};