Missing Undefined check in React.useState()

[ukntpm]

Problem

Currently, there is missing undefined check in React.useState(). Check here : https://github.com/uber/react-view/blob/fed53e07aede745e24f00ae4fc20e80f2ad7fc39/src/ast.ts#L228-L231 Since we are not passing any argument in React.useState(), it's not rendering appropriate content.

Example Code

const [initialCode, setInitialCode] = React.useState("");
const {compilerProps, errorProps, editorProps} = useView({
    initialCode
  });

React.useEffect(() => {
setInitialCode(`() => {
      const [content, setContent] = React.useState(); // not passing any argument
      const text: string = "Hey";
      return <h2>{text}</h2>;
    }`)
});