wp-calypso/client/state/billing-transactions/individual-transactions/reducer.ts

import {
	BILLING_TRANSACTION_ERROR_CLEAR,
	BILLING_TRANSACTION_RECEIVE,
	BILLING_TRANSACTION_REQUEST,
	BILLING_TRANSACTION_REQUEST_FAILURE,
	BILLING_TRANSACTION_REQUEST_SUCCESS,
} from 'calypso/state/action-types';
import { combineReducers, keyedReducer } from 'calypso/state/utils';
import type { BillingTransaction } from '../types';
import type { AnyAction } from 'redux';

/**
 * Returns the updated requests state after an action has been dispatched.
 * The state is a Boolean - true if a transaction is being requested
 */
export const requesting = ( state = false, action: AnyAction ): boolean => {
	switch ( action.type ) {
		case BILLING_TRANSACTION_REQUEST:
			return true;
		case BILLING_TRANSACTION_REQUEST_FAILURE:
			return false;
		case BILLING_TRANSACTION_REQUEST_SUCCESS:
			return false;
	}

	return state;
};

/**
 * Returns the updated error state after an action has been dispatched.
 * The state is a Boolean - true if a transaction request has failed
 */
export const error = ( state = false, action: AnyAction ): boolean => {
	switch ( action.type ) {
		case BILLING_TRANSACTION_REQUEST_FAILURE:
			return true;
		case BILLING_TRANSACTION_REQUEST_SUCCESS:
			return false;
		case BILLING_TRANSACTION_ERROR_CLEAR:
			return false;
	}

	return state;
};

/**
 * Returns the updated data state after an action has been dispatched.
 * The state contains the transaction data after a successful fetch
 */
export const data = ( state = null, action: AnyAction ): BillingTransaction | null => {
	switch ( action.type ) {
		case BILLING_TRANSACTION_RECEIVE: {
			const { receipt } = action;
			return receipt;
		}
	}

	return state;
};

export default keyedReducer(
	'transactionId',
	combineReducers( {
		requesting,
		error,
		data,
	} )
);