Overriding the left header button in a custom header

NavigationHeader.js

'use strict';
import React, {PureComponent} from 'react';
import {Header} from 'react-navigation';

export default class NavigationHeader extends PureComponent {
	getScreenDetails = (screen, ...args) => {
		const screenDetails = this.props.getScreenDetails(screen, ...args);
		const {navigate, goBack} = screenDetails.navigation;

		return {
			...screenDetails,
			options: {
				...screenDetails.options,
				headerLeft: (
					screenDetails.options.headerLeft ||
					screen.index > 0
						? <MyCustomBackButton {...} />
						: <MyCustomDrawerMenu {...} />,
			},
		};
	}

	render() {
		return (
			<Header
				{...this.props}
				getScreenDetails={this.getScreenDetails} />
		);
	}
}