Invariant Violation error thrown when testing on Stateful Component #284

qingweibinary · 2016-03-28T07:10:25Z

I am using React 15.

I have a component which call setTimeout in componentWillMount, the function is similar to

class Test extends Component {
    componentWillMount() {
        this.timer = setTimeout(() => this.setState(....), 4000);
    }
    // .....
}

When the timer is triggered, an error is thrown as follow

Invariant Violation: React DOM tree root should always have a node reference.

Here's a related issue on React
facebook/react#6232

Is there anyway I could prevent throwing error when testing, without using JSDOM?

Edit1:
this.setState(...) to () => this.setState(...)

The text was updated successfully, but these errors were encountered:

imontiel · 2016-12-05T23:34:06Z

Do you have a componentWillUnmount that clears the timer?

You will have to run wrapper.unmount() after your tests to make sure that the componentWillUnmount gets called.

ljharb · 2018-07-06T05:33:59Z

You generally don't want to call setState inside componentWillMount.

ljharb closed this as completed Jul 6, 2018

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