ArrayField + Datagrid: if embedded data doesn't have an id, rows won't have a key and will cause a React warning

[nselikoff]

What you were expecting:
Using an ArrayField + Datagrid for embedded data that doesn't have an id prop should work without console errors

What happened instead:
I get this error in the console: Warning: Each child in a list should have a unique "key" prop.

Steps to reproduce:
Given this Show component for an "album" record:

export const AlbumShow = () => (
  <Show>
    <SimpleShowLayout>
      <ArrayField source="features">
        <Datagrid>
          <TextField source="name" />
          <TextField source="value" />
        </Datagrid>
      </ArrayField>
    </SimpleShowLayout>
  </Show>
);

Where an album has embedded features that look like this (note that features don't have an id prop):

{
  "id": 0,
  "features": [
    { "name": "title", "value": "Test Album" }
  ]
}

Related code:
You can see repro this in the simple example (checked out and run locally; I don't see warnings in codesandbox's console)
Go to a post show page that has backlinks, e.g. http://localhost:8080/#/posts/12/show

Other information:
This is where the key is set based on the id, which doesn't exist in this case:

react-admin/packages/ra-ui-materialui/src/list/datagrid/DatagridBody.tsx

Line 48 in a408de0

key: record.id,

Environment

• React-admin version: 4.0.0
• Last version that did not exhibit the issue (if applicable):
• React version: 18.0.0
• Browser: Chrome
• Stack trace (in case of a JS error):

[WiXSL]

Reproduced. Thanks!

[WiXSL]

Note that in version 4, you have to pass bulkActionButtons={false} in a Datagrid inside an ArrayField.
This is clarified in the Upgrade guide.
And I'm fixing the Show example as well #7547

[WiXSL]

Fixed by #7548

[nselikoff]

Thanks for the quick fix!