Questions should render without a fixed-height flexbox parent in React embedding

[heypoom]

The question component do not have a height by default, so the charts doesn't show up when a SDK user adds it to their page. There is also no style props to pass in height.

The component also doesn't follow the parent container's height / min-height by default, so either the parent must be a flexbox, or the user needs to add a CSS like parent > div { height: 100% } for it to work.

We should be able to render a sane height by default and allow customizing the height. It should also be able to follow the parent component's height without using CSS workarounds.