#RI-3926 workaround for pika db when there is no keys displayed due to dbsize = 0

Author: Artem

redisinsight/api/src/modules/browser/services/keys-business/scanner/strategies/standalone.strategy.spec.ts

@@ -229,8 +229,17 @@ describe('Standalone Scanner Strategy', () => {
       ]);
       expect(strategy.getKeysInfo).toHaveBeenCalledTimes(0);
     });
-    it('should not call scan when total is 0', async () => {
-      jest.spyOn(Utils, 'getTotal').mockResolvedValue(mockGetTotalResponse_3);
+    it('should call scan N times until threshold exceeds (even when total 0)', async () => {
+      jest.spyOn(Utils, 'getTotal').mockResolvedValue(0);
+
+      when(browserTool.execCommand)
+        .calledWith(
+          mockBrowserClientMetadata,
+          BrowserToolKeysCommands.Scan,
+          expect.anything(),
+          null,
+        )
+        .mockResolvedValue(['1', []]);
 
       strategy.getKeysInfo = jest.fn().mockResolvedValue([]);
 
@@ -239,10 +248,16 @@ describe('Standalone Scanner Strategy', () => {
       expect(result).toEqual([
         {
           ...mockNodeEmptyResult,
+          cursor: 1,
+          total: null,
+          scanned:
+            Math.trunc(REDIS_SCAN_CONFIG.countThreshold / getKeysDto.count)
+            * getKeysDto.count
+            + getKeysDto.count,
+          keys: [],
         },
       ]);
-      expect(browserTool.execCommand).toBeCalledTimes(0);
-      expect(strategy.getKeysInfo).toBeCalledTimes(0);
+      expect(strategy.getKeysInfo).toHaveBeenCalledTimes(0);
     });
     it('should call scan with required args', async () => {
       jest.spyOn(Utils, 'getTotal').mockResolvedValue(mockGetTotalResponse_3);

redisinsight/api/src/modules/browser/services/keys-business/scanner/strategies/standalone.strategy.ts

@@ -72,6 +72,11 @@ export class StandaloneStrategy extends AbstractStrategy {
       node.keys = node.keys.map((name) => ({ name }));
     }
 
+    // workaround for "pika" databases
+    if (!node.total && (node.cursor > 0 || node.keys?.length)) {
+      node.total = null;
+    }
+
     return [node];
   }
 
@@ -86,12 +91,11 @@ export class StandaloneStrategy extends AbstractStrategy {
     // todo: remove settings from here. threshold should be part of query?
     const settings = await this.settingsService.getAppSettings('1');
     while (
-      (node.total > 0 || isNull(node.total))
+      (node.total >= 0 || isNull(node.total))
       && !fullScanned
       && node.keys.length < count
       && (
-        (node.total < settings.scanThreshold && node.cursor)
-        || node.scanned < settings.scanThreshold
+        node.scanned < settings.scanThreshold
       )
     ) {
       let commandArgs = [`${node.cursor}`, 'MATCH', match, 'COUNT', count];