[BUG][Data Explorer] Large string error on data explorer

[abbyhu2000]

Describe the bug
One of the functional test for discover is to test the ability of rendering data entry with a large size string. When i load the large string dataset to data explorer, the hit number is not being displayed.

Current:

Expected:

To Reproduce
This is the functional test: test/functional/apps/discover/_large_string.js

[ananzh]

This error is due to chartData is undefined (no histogram chart and interval) for not time based data. So if (!hits || !chartData || !bucketInterval) return null; in src/plugins/discover/public/application/view_components/canvas/discover_chart_container.tsx will return null even we have data.

This issue is actually captured and fixed in #4821
but this line if (!hits || !chartData || !bucketInterval) return null; is reversed in PR #5029 😆

If we don't like

return (
    hits && (
      <DiscoverChart
        bucketInterval={bucketInterval}
        chartData={chartData}
        config={uiSettings}
        data={data}
        hits={hits}
        resetQuery={() => {
          window.location.href = `#/view/${savedSearch?.id}`;
          window.location.reload();
        }}
        services={services}
        showResetButton={!!savedSearch && !!savedSearch.id}
        isTimeBased={isTimeBased}
      />
    )
  );

we could simplify if (!hits || !chartData || !bucketInterval) return null; to if (!hits) return null; which could also fix the problem.