[data grid] Autosizing does not work if there are less than 4 rows

[kennyhei]

Steps to reproduce

Steps:

1. Open this link to live example with 3 rows: https://stackblitz.com/edit/react-axt64587?file=Demo.tsx
2. Click "Autosize columns" with "Include headers" checked
3. Columns are NOT autosized based on header widths only, instead it expands columns so that cell contents are fully visible as well
4. Now when you toggle off all checkbox options and click "Autosize columns" again, columns won't shrink anymore. Cell content is always fully visible.

Interesting thing here is that if there are 4 rows or more, then toggling options on/off and clicking autosize works perfectly. I froze the stackblitz project but you can test this as well using the demo example in the docs.

Docs: https://mui.com/x/react-data-grid/column-dimensions/#autosizing
In the Autosizing demo example, click "Edit in Stackblitz" or "Edit in Codesandbox".

If it's of any help, same issue happens with latest v6 version as well.

Current behavior

With 3 rows or less, if includeHeaders is set to true while all the other options are false, autosizing still behaves like includeOutliers is true. Then when you set includeHeaders back to false and autosize, cell content does not shrink.

Expected behavior

With 3 rows or less, if includeHeaders is set to true while all the other options are false, autosizing should only take header widths in the calculation. Then when you set it back to false, columns should shrink back to original size.

Context

No response

Your environment

Tried this in docs demo.

Search keywords: autosizing, datagrid

[michelengelen]

Hey @kennyhei and thanks for raising this.
I can confirm that the behavior is inconsistent between the described cases where it should be.

I'll add this to the board.