Add count option to FT.CURSOR READ (#2492)

* feat: Add count option to FT.CURSOR READ

* Update CURSOR_READ.spec.ts

---------

Co-authored-by: Leibale Eidelman <me@leibale.com>

packages/search/lib/commands/CURSOR_READ.spec.ts

@@ -4,15 +4,24 @@ import testUtils, { GLOBAL } from '../test-utils';
 import { transformArguments } from './CURSOR_READ';
 
 describe('CURSOR READ', () => {
-    it('transformArguments', () => {
+    describe('transformArguments', () => {
+        it('without options', () => {
             assert.deepEqual(
                 transformArguments('index', 0),
                 ['FT.CURSOR', 'READ', 'index', '0']
             );
         });
 
+        it('with COUNT', () => {
+            assert.deepEqual(
+                transformArguments('index', 0, { COUNT: 1 }),
+                ['FT.CURSOR', 'READ', 'index', '0', 'COUNT', '1']
+            );
+        });
+    });
+
     testUtils.testWithClient('client.ft.cursorRead', async client => {
-        const [ ,, { cursor } ] = await Promise.all([
+        const [, , { cursor }] = await Promise.all([
             client.ft.create('idx', {
                 field: {
                     type: SchemaFieldTypes.TEXT

packages/search/lib/commands/CURSOR_READ.ts

@@ -4,16 +4,27 @@ export const FIRST_KEY_INDEX = 1;
 
 export const IS_READ_ONLY = true;
 
+interface CursorReadOptions {
+    COUNT?: number;
+}
+
 export function transformArguments(
     index: RedisCommandArgument,
-    cursor: number
+    cursor: number,
+    options?: CursorReadOptions
 ): RedisCommandArguments {
-    return [
+    const args = [
         'FT.CURSOR',
         'READ',
         index,
         cursor.toString()
     ];
+
+    if (options?.COUNT) {
+        args.push('COUNT', options.COUNT.toString());
+    }
+
+    return args;
 }
 
 export { transformReply } from './AGGREGATE_WITHCURSOR';