Set min-width on header section items only when they are not empty

[yuliacech]

Summary

While working on the guided onboarding project, I noticed that when a header section item is empty, it's still rendered with a min-width setting. Instead we only render this component, if it's not empty.

Screenshot before

Checklist

• Checked in both light and dark modes
• Checked in mobile
• Checked in Chrome, Safari, Edge, and Firefox
• Props have proper autodocs and playground toggles
• Added documentation
• Checked Code Sandbox works for any docs examples
• Added or updated jest and cypress tests
• Checked for breaking changes and labeled appropriately
• Checked for accessibility including keyboard-only and screenreader modes
• Updated the Figma library counterpart
• A changelog entry exists and is marked appropriately

[kibanamachine]

Preview documentation changes for this PR: https://eui.elastic.co/pr_6158/

[kibanamachine]

Preview documentation changes for this PR: https://eui.elastic.co/pr_6158/

[miukimiu]

I wonder if we should check instead in EuiHeaderSectionItem if the component has children, if not it doesn't render at all.

// In "/src/components/header/header_section/header_section_item.tsx" instead of returning:
return (
    <div className={classes} {...rest}>
      {children}
    </div>
  );

// we check if there is a children and if is not, we don't render anything:
return children ? (
    <div className={classes} {...rest}>
      {children}
    </div>
  ) : null;

[chandlerprall]

+1 to returning null when children isn't present, this will also avoid applying the border styling when no content is present.

[yuliacech]

Thanks a lot, @miukimiu! I agree, much better handling of the empty state. Let me apply your suggestion to this PR.

[kibanamachine]

Preview documentation changes for this PR: https://eui.elastic.co/pr_6158/

[kibanamachine]

Preview documentation changes for this PR: https://eui.elastic.co/pr_6158/

[miukimiu]

Thanks, @yuliacech. LGTM! 🎉

I just have one minor suggestion for the CL.

[kibanamachine]

Preview documentation changes for this PR: https://eui.elastic.co/pr_6158/