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.
expect(e.childNodes.length).toBe(1);
        expectNode(e.childNodes[0], TEXT_NODE_TYPE, '  Text ');
      });
      itRenders('a div with an empty text child', async render => {
        const e = await render(<div>{''}</div>);
        expect(e.childNodes.length).toBe(0);
      });
      itRenders('a div with multiple empty text children', async render => {
        const e = await render(
          <div>
            {''}
            {''}
            {''}
          </div>,
        );
        if (render === serverRender || render === streamRender) {
          
          
          expect(e.childNodes.length).toBe(0);
          expect(e.textContent).toBe('');
        } else {
          expect(e.childNodes.length).toBe(3);
          expectTextNode(e.childNodes[0], '');
          expectTextNode(e.childNodes[1], '');
          expectTextNode(e.childNodes[2], '');
        }
      });
      itRenders('a div with multiple whitespace children', async render => {
        
        const e = await render(<div>{' '}{' '}{' '}</div>);