React.cloneElement(this.props.children, this.props) copies the children into the this.props.children of children itself

[arshabh]

https://jsfiddle.net/69z2wepo/55774/

please run the js fiddle given above. cloneElement copies the children into props.children of the child itself

and if the child also renders its children using the same method - an infinite loop is established and the browser maximum call stack size is exceeded.

Ideally, while cloning the children property of the props of the child should be left untouched.

[gaearon]

This looks like correct behavior. children is part of props. If you pass this.props as second argument to cloneElement, children will be there. I don’t see why you’d expect them to be treated differently in this case, since children prop is not treated differently in any other cases.

[arshabh]

Maybe we can provide a toggle or blacklist of props that we do not want to merge in such scenarios.

Here is my scenario. I am building an application using react, redux, and react-redux.
I have mapped my state values and action dispatch methods to props in my root component.

I have nested components in my application thanks to react-router. In order to pass state and dispatch methods as props to children i use

{ React.cloneElement(this.props.children, this.props) }

Now the issue is that when i use the same statement in a child to further pass down the pass state and dispatch methods as props - It renders itself which in turn again renders itself and so on - kicking in an infinite loop.

[gaearon]

I understand, but this is a very specific use case, and rather than bake it into React, I think it should be solved in userland. There are plenty of use cases where you want children to be passed so we will default to a less opinionated way, and it’s up to you to opt out and clarify what you meant with code.

For example, with spread operator:

const { children, ...otherProps } = this.props;
const newChild = React.cloneElement(children, otherProps);

Without object spread:

const { children } = this.props;

const otherProps = Object.assign({}, this.props);
delete otherProps.children;

const newChild = React.cloneElement(children, otherProps);

[arshabh]

Sounds good to me. I agree with that my suggestion is opinionated based on my case. Thanks