JS.REACT.STATE.IN.CONSTRUCTOR
State initialization in an ES6 class component should be in a constructor
This rule will enforce the state initialization style to be either in a constructor or with a class property.
Rule Options
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...
"react/state-in-constructor": [<enabled>, <mode>]
...
always mode
Will enforce the state initialization style to be in a constructor. This is the default mode.
Examples of incorrect code for this rule:
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class Foo extends React.Component {
state = { bar: 0 }
render() {
return <div>Foo</div>
}
}
Examples of correct code for this rule:
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class Foo extends React.Component {
constructor(props) {
super(props)
this.state = { bar: 0 }
}
render() {
return <div>Foo</div>
}
}
never mode
Will enforce the state initialization style to be with a class property.
Examples of incorrect code for this rule:
Copy
class Foo extends React.Component {
constructor(props) {
super(props)
this.state = { bar: 0 }
}
render() {
return <div>Foo</div>
}
}
Examples of correct code for this rule:
Copy
class Foo extends React.Component {
state = { bar: 0 }
render() {
return <div>Foo</div>
}
}
When Not To Use It
When the way a component state is being initialized doesn't matter.