FullStateReducer.js

class App extends Component {
	stateReducer = (prevState, nextState) => {
		switch (nextState.type) {
			case Toggle.TOGGLE: {
				const count = prevState.count || 0;
				const isOn = count < 4 ? nextState.on : false;

				return {
					...prevState,
					...nextState,
					count: isOn ? count + 1 : count,
					on: isOn,
				};
			}
			default:
				return nextState;
		}
	}

	render() {
		return (
			<Toggle stateReducer={this.stateReducer}>
				{({ on, onToggle, count }) => (
					<Fragment>
						<Switch on={on} onToggle={onToggle} />
						{count}
					</Fragment>
				)}
			</Toggle>
		);
	}
}