client/extensions/woocommerce/state/sites/settings/mailchimp/reducer.js
function settingsRequest( state = false, { type } ) {
	switch ( type ) {
		case WOOCOMMERCE_MAILCHIMP_SETTINGS_REQUEST:
		case WOOCOMMERCE_MAILCHIMP_SETTINGS_REQUEST_SUCCESS:
		case WOOCOMMERCE_MAILCHIMP_SETTINGS_REQUEST_FAILURE:
			return WOOCOMMERCE_MAILCHIMP_SETTINGS_REQUEST === type;
	}

	return state;
}
function settingsRequest( state = false, { type } ) {
	switch ( type ) {
		case WOOCOMMERCE_MAILCHIMP_SETTINGS_REQUEST:
		case WOOCOMMERCE_MAILCHIMP_SETTINGS_REQUEST_SUCCESS:
		case WOOCOMMERCE_MAILCHIMP_SETTINGS_REQUEST_FAILURE:
			return WOOCOMMERCE_MAILCHIMP_SETTINGS_REQUEST === type;
	}

	return state;
}
Updates state with settings request status

@param  {Object} state  Current state
@param  {Object} action Action
@return {Object}        Updated state