Apollo-client: Reopen: React-Native apps throws an error when calling `refetch`

[davidyaha]

This bug has occurred with previous versions of apollo (apollo-client #261, react-apollo #78)

To reproduce it just call reftech on a react-native app.
The error being thrown is:

One of the sources for assign has an enumerable key on the prototype chain. Are you trying to assign a prototype property? We don't allow it, as this is an edge case that we do not support. This error is a performance optimization and not spec compliant.

From what I gathered this bug has returned after moving back to object spreading thus probably being caused by the polyfil.

This is still occurring on the version 0.8.0 of apollo-client and version 0.8.1 of react-apollo.

[calebmer]

@davidyaha interesting. Do you have a stack trace so we know where this is happening? I don’t think the solution is to stop using object spreading in _all_ cases; but instead, understand the underlying issue and fix that.

[davidyaha]

This red screen is unfortunately as much as I could have gathered.

I might have found the cause though and this should be a warning maybe for any react-native user.
refetch function accept variables object as it's parameter, while react-native's onPress property passes a Proxy object to the listener callback passed to it.

meaning this will throw:

render() {
  const {data: {refetch}} = this.props;
  return (
    <TouchableOpacity onPress={refetch}>
      <Text>Refetch</Text>
    </TouchableOpacity>
  );
}

And this will not:

render() {
  const {data: {refetch}} = this.props;
  return (
    <TouchableOpacity onPress={() => refetch()}>
      <Text>Refetch</Text>
    </TouchableOpacity>
  );
}

The object assign being done inside of apollo's refetch causes the error to be thrown but it a tricky error because it does not point you to the object being changed in any way.

[calebmer]

Yep, that is definitely the cause. This isn’t a bug in Apollo Client, but we may be able to throw a more helpful error here if we added the following:

if (Object.getPrototypeOf(variables) !== Object.prototype) {
  throw new Error('Only plain objects may be used as variables.');
}

Although this case is rare enough that I don’t think we really need the check. It would also disallow some interesting use cases.

I’m going to close. Let us know if you run into any other problems 👍

[aquibyatoo]

davidyaha thx a lot and god bless you

[natterstefan]

Thank you @davidyaha. Your solution worked for me!