Description

A Rust program who reads a CSV listing series of money transactions, handles them by creating client accounts and updating their funds details, and output all account details. Transactions are processed chronologically matching their appearence order in the CSV. The details of possible transactions and handled cases are described below.

CSV format

The CSV must include a header and match the following fields: type, client, tx, amount Each following line represents a transaction, the transaction type detail can be found in structs::Operation.

See the resources directory for some CSV examples.

Output

The output will be printed to stdout and will be formated as CSV data with the following fields: client,available,held,total,locked

Invalid transaction handling

Some operations are considered invalid, and will be ignored by the program:

• withdrawal without enough available funds
• chargeback or resolve on a transaction not disputed, or with a dispute already settled/handled
• dispute on an operation different than a deposit
• dispute on a deposit more than once

You can choose to block all transactions as soon as a client account is locked, this behaviour can be turned on with env values read by the program, see Env behaviour section below.

Usage

This project is a simple Rust crate, use with the usual cargo commands.

sh$ cargo --version
cargo 1.58.0 (f01b232bc 2022-01-19)
sh$ rustc --version
rustc 1.58.1 (db9d1b20b 2022-01-20)

sh$ cargo run -- resources/example.csv
...
client,available,held,total,locked
1,1.5,0.0,1.5,false
2,2.0,0.0,2.0,false

Env behaviour

The BLOCK_LOCKED_ACCOUNTS env variable can be set to change the behaviour for locked accounts.

sh$ BLOCK_LOCKED_ACCOUNTS=true cargo run -- resources/example_dispute.csv
...
1,21.1,0.0,21.1,true
sh$ BLOCK_LOCKED_ACCOUNTS=false cargo run -- resources/example_dispute.csv
...
client,available,held,total,locked
1,19.1,2.0,21.1,true