Hoolah Code Test

Demo code for a simple transaction processor, which reads data in CSV file format.

Data Format

The data is expected to be multiple transactions, with a transaction per row where each transaction is of the form:

• ID - A string representing the transaction id
• Date - The date and time when the transaction took place (format "DD/MM/YYYY hh:mm:ss")
• Amount - The value of the transaction (dollars and cents)
• Merchant - The name of the merchant this transaction belongs to
• Type - The type of the transaction, which could be either PAYMENT or REVERSAL

The application only loads data in CSV format, with comma delimiters and no string delimiters

A Sample File

ID, Date, Amount, Merchant, Type, Related Transaction
WLMFRDGD, 20/08/2018 12:45:33, 59.99, Kwik-E-Mart, PAYMENT,
YGXKOEIA, 20/08/2018 12:46:17, 10.95, Kwik-E-Mart, PAYMENT,
LFVCTEYM, 20/08/2018 12:50:02, 5.00, MacLaren, PAYMENT,
SUOVOISP, 20/08/2018 13:12:22, 5.00, Kwik-E-Mart, PAYMENT,
AKNBVHMN, 20/08/2018 13:14:11, 10.95, Kwik-E-Mart, REVERSAL, YGXKOEIA
JYAPKZFZ, 20/08/2018 14:07:10, 99.50, MacLaren, PAYMENT,` 

Setup

The project requires only the following:

    1. Java 8+ JDK

gradle is run via the wrapper which is part of the repo and will import all other dependencies

Running

The simplest way is with the "gradle run" command with the following arguments:

• merchant name
• start date in "DD/MM/YYYY hh:mm:ss" format
• end date in "DD/MM/YYYY hh:mm:ss" format
• full file path of the CSV transaction file

An example is below:

gradlew run --args="Kwik-E-Mart  '20/08/2018 11:59:00' '20/08/2018 13:00:00' /Users/serge/dev/hoolah-challenge/src/test/resources/transactions1.csv"

Building and Testing

Build with:

gradlew build

Run tests with:

gradlew test    

Limitations

• Only tested in OSX environments
• The coverage of unit tests is not exhaustive, but illustrates how a full suite of tests would look like
• Simplistic transaction database not suitable for large numbers of transactions
• Minimal logging