CLI console app to work with NFT Wallet

Data structures that I have used are strictly linked for the Task. My solution is focused on the ability to efficiently execute 3 types of tasks:

• Persist information about ownership relationshop between imaginary NFT token ids and NFT wallet addresses provided in the task
• Quickly answer what wallet contains a token, by token Id.
• Quickly answer what tokens are owned by certain wallet.
• Efficiently change the ownership of the Token between the wallet addresses.

I also tried to create the solution to fit the tight deadlines.

There are also a few things I skip and maybe return to it later. For example, if we need data integrity validation, I would probably go with some other ideas (like Merkle Trees used in the industry).

Prerequisites

To build the solution you need to have .NET Core 6.0 SDK installed.

To open and review the source code it's best to have:

• Visual Studio 2022
• .NET Core 6.0

How to run

Windows

dotnet build dotnet run

The application will show you a general help how to use it and list the available commands (see below in this instruction).

Commands

Nft.App --help Description: Wallet CLI app to work with NFT tokens.

Usage: Nft.App [command] [options]

Options: --version Show version information -?, -h, --help Show help and usage information

Commands: --read-file Reads transactions from the specified location. --read-inline Reads either a single json element, or an array of json elements representing transactions as an argument. --nft Returns ownership information for the nft with the given id. --wallet

Lists all NFTs currently owned by the wallet of the given address. --reset Deletes all data previously processed by the program.

How it works (Example)

There is transactions.json comes as an example file with list of transactions to quickly resume the state (for testing). Execute following commands:

Nft.App --read-file transactions.json Read 5 transaction(s)

Nft.App --nft 0xA000000000000000000000000000000000000000 Token 0xA000000000000000000000000000000000000000 is not owned by any wallet

Nft.App --nft 0xB000000000000000000000000000000000000000 Token 0xA000000000000000000000000000000000000000 is owned by 0x3000000000000000000000000000000000000000

Nft.App --nft 0xC000000000000000000000000000000000000000 Token 0xC000000000000000000000000000000000000000 is owned by 0x3000000000000000000000000000000000000000

Nft.App --nft 0xD000000000000000000000000000000000000000 Token 0xA000000000000000000000000000000000000000 is not owned by any wallet

Nft.App --read-inline "{ "Type": "Mint", "TokenId": "0xD000000000000000000000000000000000000000", "Address": "0x1000000000000000000000000000000000000000" }" Read 1 transaction(s)

Nft.App --nft 0xD000000000000000000000000000000000000000 Token 0xA000000000000000000000000000000000000000 is owned by 0x1000000000000000000000000000000000000000

Nft.App --wallet 0x3000000000000000000000000000000000000000 Wallet 0x3000000000000000000000000000000000000000 holds 2 Tokens: 0xB000000000000000000000000000000000000000 0xC000000000000000000000000000000000000000

Nft.App -—reset Program was reset

Nft.App --wallet 0x3000000000000000000000000000000000000000 Wallet 0x3000000000000000000000000000000000000000 holds no Tokens

External dependencies

For running app

• .NET Core 6.0
• System.CommandLine (it is still in beta, but it exists for a long time and allow to easily build Command Line tools)
• Newtonsoft.Json (to work with JSON)
• Newtonsoft.Json.Schema (to validate JSON Schema - IT'S NOT FREE for production apps)

For running tests using Visual Studio

dotnet add package FluentAssertions dotnet add package Microsoft.NET.Test.Sdk dotnet add package Moq dotnet add package xunit dotnet add package xunit.runner.visualstudio

Author

Anton Yarkov (C) 2023 anton.yarkov@gmail.com +34 662 798 010 https://optiklab.github.io/