What is the bare minimum implementation for UUPS Smart Contract using upgradable-plugin

Support Upgrades
1

I want to Create a Simple Counter Increment/decrement Smart Contract. Just to understand how we can implement UUPS in any project.

Counter.sol


// SPDX-License-Identifier: MIT
pragma solidity 0.8.4;
import "@openzeppelin/contracts-upgradeable/proxy/utils/UUPSUpgradeable.sol";

abstract contract Counter is UUPSUpgradeable{
    uint public counter;
    address public implmentation;
    address public owner;
    function initialize(uint intialValue) public {
        counter = intialValue;
        owner = msg.sender;
    }

    function incrementByOne() public {
        counter++;
    }

    function upgradeTo(address newImplementation) external virtual override {
        _upgradeTo(newImplementation);
    }

    function _authorizeUpgrade(address newImplementation) internal virtual override{
        require(msg.sender==owner,"Unauthorised Upgrade");
        _upgradeTo(newImplementation);
    }

}

I have tried already to resolve errors but yet not find a proper doc/instructions to follow.

Error:  *** Deployment Failed ***

"Counter" is an abstract contract or an interface and cannot be deployed.
   * Import abstractions into the '.sol' file that uses them instead of deploying them separately.
   * Contracts that inherit an abstraction must implement all its method signatures exactly.
   * A contract that only implements part of an inherited abstraction is also considered abstract.

    at Deployer._preFlightCheck (/home/rishabh/.nvm/versions/node/v14.0.0/lib/node_modules/truffle/build/webpack:/packages/deployer/src/deployment.js:179:1)

If anyone has implemented this UUPS proxy pattern, Please share the code or help me anyway possible. Thanks in advance.

2

Remove the abstract keyword from the contract definition. This problem doesn’t seem related to UUPS.

3

This works. Once I refer the docs for this. It’s simple that abstract contracts don’t generate bytecode for EVM to run.

4

How we can do this same thing with the pragma version 0.7.6?

5

Our UUPS implementation is only available for Solidity 0.8.