How to fix Warning: Component did not properly override the render method in React

The quickest fix is to add the override keyword before your render method declaration. This explicitly tells TypeScript that you're intentionally overriding a parent class method:

import { Component } from 'react';

interface MyComponentProps {
  title: string;
}

export class MyComponent extends Component<MyComponentProps> {
  override render() {
    return (
      <div>
        <h1>{this.props.title}</h1>
      </div>
    );
  }
}

This is the correct and recommended approach when using TypeScript 4.3+ with React class components.

If you have multiple class components, you'll need to add override to each render method. Use your IDE's find-and-replace feature to locate all occurrences:

1. Search for the pattern: render()\s*{ or render()\s*:
2. Review each match in class components
3. Add override before each render method

Example command for bulk updating (use with caution):

# Preview changes first
grep -r "render()" src/components --include="*.tsx"

If you override other React lifecycle methods, they also need the override keyword:

export class MyComponent extends Component<Props, State> {
  override componentDidMount() {
    // Initialization logic
  }

  override componentDidUpdate(prevProps: Props) {
    // Update logic
  }

  override componentWillUnmount() {
    // Cleanup logic
  }

  override render() {
    return <div>Content</div>;
  }
}

This includes methods like componentDidMount, componentDidUpdate, componentWillUnmount, shouldComponentUpdate, getDerivedStateFromProps, and getSnapshotBeforeUpdate.

Check if noImplicitOverride is explicitly enabled in your TypeScript configuration:

{
  "compilerOptions": {
    "strict": true,
    "noImplicitOverride": true,
    // other options...
  }
}

Note that noImplicitOverride may be enabled implicitly if you're using "strict": true or certain preset configurations. If you want to temporarily disable this check (not recommended), you can set "noImplicitOverride": false.

After adding the override keyword, verify that:

1. TypeScript compilation succeeds without errors
2. The component renders correctly in your application
3. No new type errors were introduced

Run your TypeScript compiler:

npx tsc --noEmit

And test your component:

npm run test
npm run build

If you're starting a new project or refactoring, consider using React function components with hooks instead of class components. Function components don't have this issue:

import { useState, useEffect } from 'react';

interface MyComponentProps {
  title: string;
}

export function MyComponent({ title }: MyComponentProps) {
  const [count, setCount] = useState(0);

  useEffect(() => {
    // Equivalent to componentDidMount
  }, []);

  return (
    <div>
      <h1>{title}</h1>
      <button onClick={() => setCount(count + 1)}>{count}</button>
    </div>
  );
}

Function components are the modern React standard and avoid class-based inheritance issues entirely.