New rule: react-no-set-state-in-update-lifecycle

[adidahiya]

There are a couple places I'd like to ban this.setState in component lifecycle methods:

1. in componentWillUpdate

Doing this can lead to infinite recursion.

2. in componentDidUpdate

Same as eslint rule https://github.com/yannickcr/eslint-plugin-react/blob/master/docs/rules/no-did-update-set-state.md

3. in componentWillMount

componentWillMount() is invoked immediately before mounting occurs. It is called before render(), therefore setting state in this method will not trigger a re-rendering. Avoid introducing any side-effects or subscriptions in this method.

[brsanthu]

@adidahiya Related to state, every component which has state, should override componentWillReceiveProps. Otherwise, component will work on old state, which would have initialized based on initial props. So is it possible to add a rule to detect that and warn? (should I create a new issue for this?)

[adidahiya]

@brsanthu yeah, that should be filed as a separate issue.

It sounds like you're referring to this pattern?

constructor(props) {
    // initialize based on initial props
    this.state = { ... };
}

This seems to be the only situation where a missing componentWillRecieveProps implementation is likely wrong. Otherwise, you can happily use stateful components without implementing this lifecycle method.

[adidahiya]

Closing due to deprecation timeline, see #210