FX Exchange Programming Exercise

The purpose of this exercise is to build a small CLI app that will convert monetary amounts between different currencies. The application has a separate JSON configuration file which holds the foreign exchange values against one base currency but the implementation can be adjusted to pull these values from an external source if needed.

You can run it with the dotnet command. The amounts are expressed with the comma used for the decimal point.

git clone https://github.com/rafalbielec/fxexchange.git
cd fxexchange
dotnet run --project src/Exchange
dotnet run --project src/Exchange EUR/DKK 1
dotnet run --project src/Exchange EUR/DKK 2,59
dotnet run --project src/Exchange USD/EUR 35,53

JSON configuration file

The JSON configuration file is called currencies.json and it has the following format. The base currency is the Danish Krone and the rest of the currencies are exchange rates against it for 100 DKK.

{
  "baseCurrency": "DKK",
  "exchangeRates": [
    { "name": "EUR", "amount": 743.94 },
    { "name": "USD", "amount": 663.11 },
    { "name": "GBP", "amount": 852.85 },
    { "name": "SEK", "amount": 76.1 },
    { "name": "NOK", "amount": 78.4 },
    { "name": "CHF", "amount": 683.58 },
    { "name": "JPY", "amount": 5.974 }
  ]
}

NuGet packages used

• IoC.Container
• System.Text.Json
• NSubstitute

Unit and Integration tests

The solution also features a separate xunit test project which contains unit tests and integration tests.

Tokei code summary

cargo install tokei
tokei

Language	Files	Lines	Code	Comments	Blanks
C#	30	920	774	36	110
JSON	3	26	26	0	0
MSBuild	3	65	65	0	0
Visual Studio Solution	1	34	33	0	1
Markdown	1	50	0	35	15
Total	38	1095	898	71	126