Method enrichChangeMessage

packages/db/src/collection/state.ts:310–333

* Creates a change message with virtual properties. * Uses the "add-if-missing" pattern so that pass-through from upstream * collections works correctly.

(
    change: ChangeMessage<TOutput, TKey>,
  )

   * collections works correctly.
   */
  public enrichChangeMessage(
    change: ChangeMessage<TOutput, TKey>,
  ): ChangeMessage<WithVirtualProps<TOutput, TKey>, TKey> {
    const { __virtualProps } = change as InternalChangeMessage<TOutput, TKey>
    const enrichedValue = __virtualProps?.value
      ? this.enrichWithVirtualPropsSnapshot(change.value, __virtualProps.value)
      : this.enrichWithVirtualProps(change.value, change.key)
    const enrichedPreviousValue = change.previousValue
      ? __virtualProps?.previousValue
        ? this.enrichWithVirtualPropsSnapshot(
            change.previousValue,
            __virtualProps.previousValue,
          )
        : this.enrichWithVirtualProps(change.previousValue, change.key)
      : undefined

    return {
      key: change.key,
      type: change.type,
      value: enrichedValue,
      previousValue: enrichedPreviousValue,
      metadata: change.metadata,
    } as ChangeMessage<WithVirtualProps<TOutput, TKey>, TKey>
  }

  /**
   * Get the current value for a key enriched with virtual properties.