It seems problematic to allow arbitary non-lowercase attribute on HTML nodes. Because the server has no ability to keep them case sensitive (HTML isn't). So they will end up different on the client.

We should probably warn if the attribute is not a known one *and* is not lowercase.
expect(e.hasAttribute('aria-label')).toBe(false);
      });
      itRenders('"aria" attribute with a warning', async render => {
        
        const e = await render(<div aria="hello" />, 1);
        expect(e.getAttribute('aria')).toBe('hello');
      });
    });
    describe('cased attributes', function() {
      itRenders(
        'badly cased aliased HTML attribute with a warning',
        async render => {
          const e = await render(<meta httpequiv="refresh" />, 1);
          expect(e.hasAttribute('http-equiv')).toBe(false);
          expect(e.getAttribute('httpequiv')).toBe('refresh');
        },
      );
      itRenders('badly cased SVG attribute with a warning', async render => {
        const e = await render(<text textlength="10" />, 1);
        expect(e.getAttribute('textLength')).toBe('10');
      });
      itRenders('no badly cased aliased SVG attribute alias', async render => {
        const e = await render(<text strokedasharray="10 10" />, 1);
        expect(e.hasAttribute('stroke-dasharray')).toBe(false);
        expect(e.getAttribute('strokedasharray')).toBe('10 10');
      });
      itRenders(
        'no badly cased original SVG attribute that is aliased',
        async render => {
          const e = await render(<text stroke-dasharray="10 10" />, 1);