fix: Fixes cursors. (#17)

Author: ryasmi

package-lock.json

@@ -25,7 +25,7 @@
     "check-coverage": true
   },
   "dependencies": {
-    "@js-entity-repos/core": "^7.1.0",
+    "@js-entity-repos/core": "^8.0.0",
     "knex": "^0.14.2",
     "lodash": "^4.17.4"
   },

package.json

@@ -32,6 +32,12 @@ before(async () => {
 });
 
 facadeTest(factory<TestEntity>({
+  constructEntity: (document) => {
+    return {
+      ...document,
+      booleanProp: document.booleanProp === 1,
+    };
+  },
   db,
   entityName: 'Test Entity',
   tableName,

src/factory.test.ts

@@ -14,7 +14,10 @@ import replaceEntity from './functions/replaceEntity';
 export default <E extends Entity>(factoryConfig: FactoryConfig<E>): Facade<E> => {
   const facadeConfig: FacadeConfig<E> = {
     constructDocument: (patch) => patch,
-    constructEntity: (document) => document,
+    constructEntity: (document) => {
+      /* istanbul ignore next - Had to be overriden in tests for booleans */
+      return document;
+    },
     constructFilter: (filter) => filter,
     constructSort: (sort) => sort,
     defaultPaginationLimit: 10,

src/factory.ts

@@ -1,12 +1,14 @@
 import GetEntities from '@js-entity-repos/core/dist/signatures/GetEntities';
+import { end, start } from '@js-entity-repos/core/dist/types/Cursor';
 import Entity from '@js-entity-repos/core/dist/types/Entity';
 import Pagination from '@js-entity-repos/core/dist/types/Pagination';
 import { forward } from '@js-entity-repos/core/dist/types/PaginationDirection';
 import Sort from '@js-entity-repos/core/dist/types/Sort';
 import SortOrder, { asc } from '@js-entity-repos/core/dist/types/SortOrder';
-import createCursorFromEntity from '@js-entity-repos/core/dist/utils/createCursorFromEntity';
+import createEndCursorResult from '@js-entity-repos/core/dist/utils/createEndCursorResult';
+import createGetEntitiesResult from '@js-entity-repos/core/dist/utils/createGetEntitiesResult';
 import createPaginationFilter from '@js-entity-repos/core/dist/utils/createPaginationFilter';
-import { first, last, mapValues } from 'lodash';
+import { mapValues } from 'lodash';
 import FacadeConfig from '../FacadeConfig';
 import filterEntities from '../utils/filterEntities';
 
@@ -16,14 +18,17 @@ const xor = (conditionA: boolean, conditionB: boolean) => {
 
 export default <E extends Entity>(config: FacadeConfig<E>): GetEntities<E> => {
   const defaultPagination: Pagination = {
-    cursor: undefined,
+    cursor: start,
     direction: forward,
     limit: config.defaultPaginationLimit,
   };
   const defaultSort = { id: asc } as Sort<E>;
   return async ({ filter = {}, sort = defaultSort, pagination = defaultPagination }) => {
-    const table = (await config.db()).table(config.tableName);
+    if (pagination.cursor === end) {
+      return createEndCursorResult(pagination);
+    }
 
+    const table = (await config.db()).table(config.tableName);
     const paginationFilter = createPaginationFilter(pagination, sort);
     const fullFilter = { $and: [filter, paginationFilter] };
     const constructedFilter = config.constructFilter(fullFilter);
@@ -36,13 +41,13 @@ export default <E extends Entity>(config: FacadeConfig<E>): GetEntities<E> => {
     const sortQuery = Object.keys(knexSort).reduce((result, sortKey) => {
       return result.orderBy(sortKey, (knexSort as any)[sortKey]);
     }, filterQuery);
-    const limitQuery = sortQuery.limit(pagination.limit);
-    const documents = await Promise.resolve(limitQuery);
+    const limitQuery = sortQuery.limit(pagination.limit + 1);
+    const results = await Promise.resolve(limitQuery);
+    const documents = results.slice(0, pagination.limit);
 
-    const entities = documents.map(config.constructEntity);
-    const nextCursor = createCursorFromEntity(last(entities), sort);
-    const previousCursor = createCursorFromEntity(first(entities), sort);
+    const entities: E[] = documents.map(config.constructEntity);
+    const isEnd = results.length <= pagination.limit;
 
-    return { entities, nextCursor, previousCursor };
+    return createGetEntitiesResult({ entities, isEnd, pagination, sort });
   };
 };