A checking account from a bank allows for putting (deposits, salaries, credits) or taking (purchases, withdrawals, debits) money at any given time.
You can also check what is your current balance or your account statement, containing all operations that happened between two dates, along with the account's daily balance.
I found out that my concurrency was a mess, it's really hard to keep track of the index in a vector when dealing with concurrency in the system. My solution was very simple, store transactions in a hash-map and use a counter as an index generator. This way the tx-id stored in the account doesn't need to match with a specific index in the vector.
Most of the code was refactored, I tried to rely in functional style like map, reduce, apply and build a specific function following the same principles. This helped me to reuse a base function and send functions as parameter to extend its functionality.
Got rid of db_fixture.clj and include precise parameters per function. Readability was improved.
No need to reinvent the wheel with date-helpers. I changed the date library to one that is easier to use and has a decrease day function.
I was not able to fix full test suite including the handler tests, sometimes it works and some times it doesn't. Please got to de test section for more information.
I decided to store accounts in a nested map to be flexible with account numbers, each account contains a vector ref that keeps a record of the transactions done by the account.
Transactions are stored in hash-map of maps containing the corresponding information.
Both accounts and transactions are ref's to ensure it can run in a concurrent-safe way and use alter to apply STM dependency rules.
To keep the next tx-id or account id, I created 2 global atoms contain each of the id's.
Every time a new account is created the atom is increased by one using swap to secure it from other threads. Also the new-tx-id is added to the account tx-ids ref.
Clojure 1.10.0
Leiningen 2.9.1
git clone https://github.com/aldosolorzano/checking-account.git
lein ring server
This will open a window at your localhost:3000
The application is preloaded with an account and some transactions to test end-points right away.
Use account number 100 or create a new one and create transactions to test endpoints
/accounts/100/end-point
This error is thrown when an invalid account is given
{
"errors": "Account doesn't exists"
}This error is thrown when no body is given in post request
{
"errors": ":init, :end, required. Add to body"
}This error is thrown when an invalid date is given
{ "description": "Deposit", "amount": 100, "date": 1234, "type": "deposit"}{
"errors": ":date, Invalid tx params"
}The preloaded account is in negative balance
-38.57The preloaded account is in negative balance, no end date included
[
{
"principal": "25.23",
"start": "14/10/2019",
"end": "15/10/2019"
},
{
"principal": "28.57",
"start": "16/10/2019",
"end": "21/10/2019"
},
{
"principal": "38.57",
"start": "22/10/2019"
}
]{ "init": "11/10/2019", "end": "14/10/2019" }| Parameter | Description |
|---|---|
| init | Inclusive initial date. |
| end | Inclusive end date. |
[
{
"11/10/2019": [
"Deposit 1000"
],
"balance": "1000.00"
},
{
"12/10/2019": [
"Purchase of a flight -800"
],
"balance": "200.00"
},
{
"14/10/2019": [
"Purchase on Uber -45.23",
"Withdrawal -180"
],
"balance": "-25.23"
}
]{ "description": "Deposit", "amount": 100, "date": "25/10/2019", "type": "deposit"}| Parameter | Description |
|---|---|
| description | Brief description of transaction(string) |
| amount | Transaction amount(int or float) |
| date | Day, month and year of transaction |
| type | Transactions are divided in three types deposit, purchase, withdrawal |
{
"id": 7,
"account": 100,
"date": "25/10/2019",
"amount": 100,
"description": "Deposit",
"type": "deposit"
}{"id": 101}lein test
There is a bug with mock/compojure in the test/checking_account/handler_test.clj file, if running lein test fails, try running just the file with the command below, it will work correctly. Otherwise, try running the command lein test a couple more times.
lein test test/checking_account/handler_test.clj
Copyright © 2019 FIXME
This program and the accompanying materials are made available under the terms of the Eclipse Public License 2.0 which is available at http://www.eclipse.org/legal/epl-2.0.
This Source Code may also be made available under the following Secondary Licenses when the conditions for such availability set forth in the Eclipse Public License, v. 2.0 are satisfied: GNU General Public License as published by the Free Software Foundation, either version 2 of the License, or (at your option) any later version, with the GNU Classpath Exception which is available at https://www.gnu.org/software/classpath/license.html.