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.
return {x: 123};
            }
          }
          await render(<ObjectComponent />, 1);
        },
        'Objects are not valid as a React child (found: object with keys {x}).' +
          (__DEV__
            ? ' If you meant to render a collection of children, use ' +
              'an array instead.'
            : ''),
      );
      itThrowsWhenRendering(
        'top-level object',
        async render => {
          await render({x: 123});
        },
        'Objects are not valid as a React child (found: object with keys {x}).' +
          (__DEV__
            ? ' If you meant to render a collection of children, use ' +
              'an array instead.'
            : ''),
      );
    });
  });
  describe('form controls', function() {
    describe('inputs', function() {
      itRenders('an input with a value and an onChange', async render => {
        const e = await render(<input value="foo" onChange={() => {}} />);
        expect(e.value).toBe('foo');
      });