AlertProvider.jsx

const AlertContext = React.createContext<IAlertContext>({
  alert: undefined,
  showAlert: (alert) => {},
});
// Here we are creating a context with default values

class AlertProvider extends React.Component {
  state = {
    alert: undefined
  };

  render() {
    const { children } = this.props;
    return (
      <AlertContext.Provider
        value={{
          ...this.state,
          showAlert: this.showAlert,
        }}
      >
        {children}
      </AlertContext.Provider>
    );
  }

  private showAlert = alert => {
    this.setState({
      alert
    });
  };
}