On-Chain NFT Assignment
The goal of this exercise is to develop an on-chain NFT collection and host it on opensea.
A base contract is given here - contracts/DappCampNFT.sol
. Use this contract to create your own NFT collection. Complete the following functions:
-
The collection array can contain the different texts or attributes you want to randomize for SVG image. You can choose different texts or attributes for this collection based on your creativity.
-
random(string memory input)
: Given an input string(input
), it should return a random number -
pluck(uint256 tokenId, string memory keyPrefix, string[] memory sourceArray)
: It should generate a random number using bothkeyPrefix
andtokenId
and then pick and return an element from the givensourceArray
containing multiple elements -
tokenURI(uint256 tokenId)
: This function should use the pluck and random functions defined above to generate a unique NFT metadata for each tokenId. It should return a string containing base64 json data which further contains base64 encoded svg image. An example data has been broken down for you below-
Returned value from tokenURI function -
data:application/json;base64,eyJuYW1lIjogIkNvbG9yICMxIiwgImRlc2NyaXB0aW9uIjogIkJyaW5nIGNvbG9ycyB0byBsaWZlLiIsICJpbWFnZSI6ICJkYXRhOmltYWdlL3N2Zyt4bWw7YmFzZTY0LFBITjJaeUI0Yld4dWN6MGlhSFIwY0RvdkwzZDNkeTUzTXk1dmNtY3ZNakF3TUM5emRtY2lJSEJ5WlhObGNuWmxRWE53WldOMFVtRjBhVzg5SW5oTmFXNVpUV2x1SUcxbFpYUWlJSFpwWlhkQ2IzZzlJakFnTUNBeE1EQWdNVEF3SWo0OGNtVmpkQ0IzYVdSMGFEMGlNVEF3SWlCb1pXbG5hSFE5SWpFd01DSWdabWxzYkQwaVlteDFaU0lnTHo0OEwzTjJaejQ9In0=
-
Here the prefix
data:application/json;base64,
is followed by base64 json data which decodes into following -{"name": "Color #1", "description": "Bring colors to life.", "image": "data:image/svg+xml;base64,PHN2ZyB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciIHByZXNlcnZlQXNwZWN0UmF0aW89InhNaW5ZTWluIG1lZXQiIHZpZXdCb3g9IjAgMCAxMDAgMTAwIj48cmVjdCB3aWR0aD0iMTAwIiBoZWlnaHQ9IjEwMCIgZmlsbD0iYmx1ZSIgLz48L3N2Zz4="}
-
The
image
field of the json above is a base64 encoded SVG prefixed withdata:image/svg+xml;base64,
. On decoding the base64 SVG you get<svg xmlns="http://www.w3.org/2000/svg" preserveAspectRatio="xMinYMin meet" viewBox="0 0 100 100"><rect width="100" height="100" fill="blue" /></svg>
-
You can use base64decode.com to decode base64 strings and use svgviewer.dev to view the svg image
-
Setup
-
Use the following command to install dependencies
npm install
Deployment
-
Rename
.env.example
to.env
. Replace<<Your ALCHEMY_API_KEY>>
with your alchemy API key and<<Your WALLET_PRIVATE_KEY>>
with your wallet's private key -
The deploy script is already provided for you. Run the following command to deploy to test network
npx hardhat run scripts/deploy.js --network rinkeby
-
Once deployed to rinkeby, you can view your NFT collection on opensea by substituting your
CONTRACT_ADDRESS
andTOKEN_ID
in the below URLhttps://testnets.opensea.io/assets/CONTRACT_ADDR/TOKEN_ID
-
Once deployed you can mint your tokens by substituting the deployed contract address in
scripts/mint.js
and running the following commandnpx hardhat run scripts/mint.js --network rinkeby
Evaluation
-
Create a fork of this repo
-
Install all dependencies
npm install
-
Make changes to the
contract/DappCampNFT.sol
file. The basic sanity tests intest/DappCampNFT.spec.js
should run successfully. -
Run Tests
npm test
-
Create a pull request from your forked repo to main branch of original repo to run the github workflow. The name of the pull request should be in the format
YOUR_NAME - On-Chain NFT Assignment