🐛Fixed pagination for PostgreSQL connector

tdrive/backend/node/src/core/platform/services/database/services/orm/connectors/postgres/postgres-query-builder.ts

@@ -103,7 +103,7 @@ export class PostgresQueryBuilder {
         limit = Number.parseInt(options.pagination.limitStr);
       }
       if (options.pagination.page_token) {
-        offset = (Number.parseInt(options.pagination.page_token) - 1) * limit;
+        offset = Number.parseInt(options.pagination.page_token) * limit;
       }
     }
     return [query(whereClause, orderByClause, limit, offset), values];

tdrive/backend/node/src/core/platform/services/database/services/orm/connectors/postgres/postgres.ts

@@ -230,10 +230,7 @@ export class PostgresConnector extends AbstractConnector<PostgresConnectionOptio
       entities.push(entity);
     });
 
-    const nextPageToken = options?.pagination?.page_token || "0";
+    const nextPage = this.nextPage(options.pagination, entities.length);
-    const limit = parseInt(options?.pagination?.limitStr);
-    const nextToken = entities.length === limit && (parseInt(nextPageToken) + limit).toString(10);
-    const nextPage: Paginable = new Pagination(nextToken, options?.pagination?.limitStr || "100");
     logger.debug(
       `services.database.orm.postgres.find - Query Result (items=${entities.length}): ${query}`,
     );
@@ -241,6 +238,14 @@ export class PostgresConnector extends AbstractConnector<PostgresConnectionOptio
     return new ListResult<EntityType>(entityDefinition.type, entities, nextPage);
   }
 
+  nextPage(pagination: Pagination, entitiesLength: number) {
+    const nextPageToken = pagination?.page_token || "0";
+    const limit = parseInt(pagination?.limitStr);
+    const nextToken = entitiesLength === limit && (parseInt(nextPageToken) + 1).toString(10);
+    const nextPage: Paginable = new Pagination(nextToken, pagination?.limitStr || "100");
+    return nextPage;
+  }
+
   // eslint-disable-next-line @typescript-eslint/no-unused-vars
   remove<Entity>(entities: Entity[]): Promise<boolean[]> {
     return Promise.all(entities.map(entity => this.removeOne(entity)));

tdrive/backend/node/test/e2e/documents/documents.spec.ts

@@ -44,7 +44,7 @@ describe("the Drive feature", () => {
     currentUser = await UserApi.getInstance(platform);
   });
 
-  afterAll(async () => {
+  afterEach(async () => {
     await platform?.tearDown();
     platform = null;
   });

tdrive/backend/node/test/unit/core/services/database/services/orm/connectors/postgres/postgres.test.ts

@@ -7,6 +7,7 @@ import {
 } from "../../../../../../../../../src/core/platform/services/database/services/orm/connectors/postgres/postgres";
 import { getEntityDefinition } from '../../../../../../../../../src/core/platform/services/database/services/orm/utils';
 import { TestDbEntity, normalizeWhitespace, newTestDbEntity } from "./utils";
+import { Pagination } from "../../../../../../../../../src/core/platform/framework/api/crud-service";
 
 describe('The Postgres Connector module', () => {
 
@@ -28,6 +29,28 @@ describe('The Postgres Connector module', () => {
     jest.clearAllMocks();
   });
 
+  test('nextPage successfully iterate starting from null value', () => {
+    //given
+    const pagination = new Pagination(null, "5");
+
+    //when
+    let nextPage = subj.nextPage(pagination, 5);
+
+    //then
+    expect(nextPage.page_token).toEqual("1")
+    expect(nextPage.limitStr).toEqual("5");
+
+    nextPage = subj.nextPage(Pagination.fromPaginable(nextPage), 5);
+    //then
+    expect(nextPage.page_token).toEqual("2")
+    expect(nextPage.limitStr).toEqual("5");
+
+    nextPage = subj.nextPage(Pagination.fromPaginable(nextPage), 1);
+    //then
+    expect(nextPage.page_token).toEqual(false)
+    expect(nextPage.limitStr).toEqual("5");
+  })
+
   test('createTable generates table structure queries', async () => {
     // given
     const definition = getEntityDefinition(new TestDbEntity());