TypeError: Cannot read properties of null (reading 'props') in Next.js: Causes and How to Fix

Verify Component Lifecycle Methods

• Ensure that your component does not attempt to read properties of `props` within the constructor or state initialization, especially if there's asynchronous data loading involved.

 

• Double-check that you're not trying to access `props` inside class properties without proper initialization.

constructor(props) {
  super(props);
  this.state = {
    example: props.initialData || null,
  };
}

Validate Data Sources

• Ensure that the data source you are trying to access has been properly initialized and is not null or undefined. Check the logic where data is fetched and assigned.

 

• Use conditional chaining or optional chaining (?.) to gracefully handle null values without throwing errors.

const data = responseData?.data;
if (data) {
  // Use data safely
}

Ensure Proper Prop Passing

• Verify that the parent component is indeed passing the required props to the child component. If using default props, ensure they are set up correctly.

 

• Props can be undefined if not specified in a parent component’s JSX, so consider providing defaultProps for any component that requires certain props.

MyComponent.defaultProps = {
  initialData: null,
};

Check Render Conditions

• Guard certain parts of your render logic to ensure components are not attempting to use null or undefined data. Use conditional rendering to manage content better.

 

• Include checks within your render methods to handle cases where props data might not yet be loaded or available.

render() {
  const { data } = this.props;
  if (!data) {
    return <LoadingSpinner />;
  }
  return <Content data={data} />;
}

Leverage Error Boundary

• Use React Error Boundaries to catch and handle errors related to unexpected null values and avert application crashes.

 

• Create a robust error handling implementation to manage components that might occasionally receive null or undefined props.

class ErrorBoundary extends React.Component {
  constructor(props) {
    super(props);
    this.state = { hasError: false };
  }

  static getDerivedStateFromError(error) {
    return { hasError: true };
  }

  render() {
    if (this.state.hasError) {
      return <h1>Something went wrong.</h1>;
    }

    return this.props.children;
  }
}