no-direct-mutation-state

Full Name in eslint-plugin-react-x

react-x/no-direct-mutation-state

Full Name in @eslint-react/eslint-plugin

@eslint-react/no-direct-mutation-state

Presets

core
recommended
recommended-typescript
recommended-type-checked

Description

Disallow direct mutation of this.state.

NEVER mutate this.state directly, as calling setState() afterwards may replace the mutation you made. Treat this.state as if it were immutable.

The only place that's acceptable to assign this.state is in a class component's constructor.

Examples

Failing

import React from "react";
 
interface MyComponentProps {}
 
interface MyComponentState {
  foo: string;
}
 
class MyComponent extends React.Component<MyComponentProps, MyComponentState> {
  state = {
    foo: "bar",
  };
 
  render() {
    return (
      <div
        onClick={() => {
          this.state.foo = "baz";
          //   ^^^^^^^^^^^^^^^^^
          //   - Do not mutate state directly. Use 'setState()' instead.
        }}
      >
        {this.state.foo}
      </div>
    );
  }
}

Passing

import React from "react";
 
interface MyComponentProps {}
 
interface MyComponentState {
  foo: string;
}
 
class MyComponent extends React.Component<MyComponentProps, MyComponentState> {
  state = {
    foo: "bar",
  };
 
  render() {
    return (
      <div
        onClick={() => {
          this.setState({ foo: "baz" });
        }}
      >
        {this.state.foo}
      </div>
    );
  }
}

no-direct-mutation-state

Description

Examples

Failing

Passing

Implementation

On this page