Function getTrackExpression

packages/core/src/render3/util/control_flow.ts:343–352

* Returns the string representation of the track expression. * * @param metadata Metadata containing the track function. * @returns

(metadata: RepeaterMetadataShape)

 * @returns
 */
function getTrackExpression(metadata: RepeaterMetadataShape): string {
  const trackByFn = metadata.trackByFn;
  if (trackByFn.name === 'ɵɵrepeaterTrackByIndex') {
    return '$index';
  }
  if (trackByFn.name === 'ɵɵrepeaterTrackByIdentity') {
    return 'item';
  }
  return 'function';
}