Follow up from https://github.com/facebook/react/pull/11616.

Here's one I found. These two invariants:

https://github.com/facebook/react/blob/7e7127387ba64f57299eaff8656542cea6fb3a2d/packages/react-reconciler/src/ReactFiberClassComponent.js#L330-L343

are in a function that's behind a DEV block:

https://github.com/facebook/react/blob/7e7127387ba64f57299eaff8656542cea6fb3a2d/packages/react-reconciler/src/ReactFiberClassComponent.js#L447-L449

I don't think this is intentional, but need to verify.

There may be more. I'll use this issue to track while https://github.com/facebook/react/pull/11616 preserves existing behavior.
const e = await render(<object data="hello" />);
        expect(e.getAttribute('data')).toBe('hello');
      });
      itRenders('no unknown data- attributes with null value', async render => {
        const e = await render(<div data-foo={null} />);
        expect(e.hasAttribute('data-foo')).toBe(false);
      });
      itRenders('unknown data- attributes with casing', async render => {
        const e = await render(<div data-fooBar="true" />, 1);
        expect(e.getAttribute('data-foobar')).toBe('true');
      });
      itRenders('unknown data- attributes with boolean true', async render => {
        const e = await render(<div data-foobar={true} />);
        expect(e.getAttribute('data-foobar')).toBe('true');
      });
      itRenders('unknown data- attributes with boolean false', async render => {
        const e = await render(<div data-foobar={false} />);
        expect(e.getAttribute('data-foobar')).toBe('false');
      });
      itRenders(
        'no unknown data- attributes with casing and null value',
        async render => {
          const e = await render(<div data-fooBar={null} />, 1);
          expect(e.hasAttribute('data-foobar')).toBe(false);
        },
      );
      itRenders('custom attributes for non-standard elements', async render => {
        const e = await render(<nonstandard foo="bar" />);
        expect(e.getAttribute('foo')).toBe('bar');