catalog: accept null as field value

Signed-off-by: Vincenzo Scamporlino <vincenzos@spotify.com>

plugins/catalog-backend/src/catalog/types.ts

@@ -295,7 +295,7 @@ export type Cursor = {
   /**
    * The values of the fields of a specific item used for paginating the data.
    */
-  sortFieldValues: string[];
+  sortFieldValues: Array<string | null>;
   /**
    * A filter to be applied to the full list of entities.
    */
@@ -313,7 +313,7 @@ export type Cursor = {
    * The catalog uses this field internally to understand if the beginning
    * of the list has been reached when performing cursor based pagination.
    */
-  firstSortFieldValues?: string[];
+  firstSortFieldValues?: Array<string | null>;
   /**
    * The number of items that match the provided filters
    */

plugins/catalog-backend/src/service/DefaultEntitiesCatalog.ts

@@ -338,7 +338,7 @@ export class DefaultEntitiesCatalog implements EntitiesCatalog {
     const limit = request?.limit ?? 20;
 
     const cursor: Omit<Cursor, 'sortFieldValues'> & {
-      sortFieldValues?: string[];
+      sortFieldValues?: (string | null)[];
     } = {
       sortFields: [defaultSortField],
       isPrevious: false,
@@ -689,5 +689,5 @@ function invertOrder(order: EntitySortField['order']) {
 }
 
 function sortFieldsFromRow(row: DbSearchRow) {
-  return [row.value!, row.entity_id];
+  return [row.value, row.entity_id];
 }