[data grid] Lazy loaded group grid with `defaultGroupingExpansionDepth={-1}` leaves some groups as skeletons.

[mbiggs-gresham]

Steps to reproduce

Steps:

1. Create a DataGrid with a dataSource, treeData, lazyLoading and defaultGroupingExpansionDepth={-1}.
2. Have a dataset of 5 parents with 2 child rows each (Only 1 level deep) so that 5 groups try to load children on initial render with multiple inflight queries. May require minimal network latency.
3. Observe not all child group fetches complete leaving some flashing as skeletons. Network requests complete, grid doesn't render them.

Current behavior

Observe not all child group fetches complete leaving some flashing as skeletons.

Expected behavior

All child groups should load.

Context

I've patched useGridDataSourceBase.js locally and it appears to resolve the issue. It's a claude fix however, so may not be correct but hopefully may help.

  Suggested fix
  
  Check the cache before clearing. The clear only needs to happen if we're actually going to make a network round-trip:

     if (parentId && parentId !== GRID_ROOT_GROUP_ID && props.signature !== 'DataGrid') {
       options.fetchRowChildren?.([parentId], [fetchParams], showChildrenLoading);
       return;
     }
  -  options.clearDataSourceState?.();
     const cacheKeys = cacheChunkManager.getCacheKeys(fetchParams);
     const responses = cacheKeys.map(cacheKey => cache.get(cacheKey));
     if (!skipCache && responses.every(response => response !== undefined)) {
       lastRequestId.current += 1;
       apiRef.current.applyStrategyProcessor('dataSourceRootRowsUpdate', { ... });
       if (standardRowsUpdateStrategyActive) apiRef.current.setLoading(false);
       return;
     }
  +  options.clearDataSourceState?.();

Your environment

npx @mui/envinfo

  Don't forget to mention which browser you used.
  Output from `npx @mui/envinfo` goes here.

Search keywords: lazyLoading defaultGroupingExpansionDepth

Order ID: 45466

[michelengelen]

Hey @MBilalShafi .. could you take a look at this? its related to the recently merged PR