support group by queries

src/makePaginate.ts

@@ -8,6 +8,7 @@ import {
   reverseOrder,
   getPrimaryKeyFields,
   isModelClass,
+  getCount,
 } from './utils';
 
 import {
@@ -81,8 +82,8 @@ const makePaginate = <ModelType extends Model>(
 
     const [instances, totalCount, cursorCount] = await Promise.all([
       modelClass.findAll(paginationQueryOptions),
-      modelClass.count(totalCountQueryOptions),
-      modelClass.count(cursorCountQueryOptions),
+      getCount(modelClass, totalCountQueryOptions),
+      getCount(modelClass, cursorCountQueryOptions),
     ]);
 
     if (before) {

src/tests/makePaginate.test.ts

@@ -207,4 +207,13 @@ describe('makePaginate', () => {
     expectIdsToEqual(result, [5, 4, 3]);
     expect(result.totalCount).toBe(3);
   });
+
+  it('paginates correctly with group by', async () => {
+    await generateTestData();
+
+    const result = await Counter.paginate({ group: 'extra' });
+
+    expectIdsToEqual(result, [1, 3]);
+    expect(result.totalCount).toBe(2);
+  });
 });

src/utils.ts

@@ -1,4 +1,4 @@
-import { Op, ModelStatic, WhereOptions, Model } from 'sequelize';
+import { Op, ModelStatic, WhereOptions, Model, CountOptions } from 'sequelize';
 import { CursorPayload, OrderConfig } from './types';
 
 export const parseCursor = (cursor: string): CursorPayload | null => {
@@ -141,3 +141,17 @@ export const getPaginationQuery = (
 export const isModelClass = (value: unknown): value is ModelStatic<any> => {
   return typeof value === 'function' && value.prototype instanceof Model;
 };
+
+export const getCount = async (
+  model: ModelStatic<any>,
+  query: CountOptions<any>,
+): Promise<number> => {
+  const countPayload = await model.count(query);
+
+  // count with group by query returns an array
+  if (Array.isArray(countPayload)) {
+    return countPayload.length;
+  }
+
+  return countPayload;
+};