Ethereum-based dApp Development with Go using go-ethereum SDK

Examples deploying smart contracts on Neon EVM Devnet using Go

This directory contains all the files necessary to deploy the following smart contracts on Neon EVM Devnet-

1. Simple storage contract.
2. ERC20 token contract.

For more details, please refer to these documentations https://goethereumbook.org/en/ and https://geth.ethereum.org/docs/developers/dapp-developer/native-bindings.

Prerequisites

1. The latest Go version.
2. The latest Solidity compiler version.

Solc installation

Please check this link to install the required solc version - https://docs.soliditylang.org/en/latest/installing-solidity.html.

Go installation

Important

If your machine already has Go installed, then please proceed to the Cloning repository step.

1. Download the latest Go version from https://go.dev/doc/install.

2. Create a directory GoProjects for your Go project development on your machine. Please run pwd inside GoProjects directory to get the full path. This will be used in Step 4 to set the $GOPATH env variable.

3. Create 3 directories /GoProjects/src, /GoProjects/pkg and /GoProjects/bin.

4. Set up the $GOPATH env variable on your machine -

• Run nano ~/.zshrc on Mac machines.
• Run nano ~/.bash_profile on Linux machines.
• Paste the following lines -

export GOPATH=<PATH_TO_YOUR_GO_PROJECTS_DIRECTORY>
export PATH=$GOPATH/bin:$PATH

5. Save your ~/.bash_profile or ~/.zshrc file.

• Run source ~/.zshrc on Mac machines.
• Run source ~/.bash_profile on Linux machines.

6. Run echo $GOPATH to check if the GOPATH is set correctly in the machine.

Cloning repository

1. Navigate to the src directory of your GOPATH.

cd $GOPATH/src

2. Run command

git clone https://github.com/neonlabsorg/go-ethereum-tutorial.git
cd go-ethereum-tutorial

Note: All the following commands should be executed inside go-ethereum-tutorial folder.

Install the required libraries inside the go-ethereum-tutorial folder

npm install

go install github.com/ethereum/go-ethereum/cmd/abigen@latest

go mod tidy

Set up .env file

Rename .env.example to .env and place your private key inside it.

Interact with the Storage smart contract

Generate the go bindings

1. Run the following commands to generate the smart contract ABI and bytecode.

solc --abi ./contracts/Storage.sol -o build

solc --bin ./contracts/Storage.sol -o build

2. Run the following command to generate the smart contract go binding inside contractsgo folder.

 abigen --abi ./build/Storage.abi --pkg contractsgo --type Storage --out ./contractsgo/Storage.go --bin ./build/Storage.bin

Run the smart contracts functions

Important

To run only the Storage contract, please comment out deploy.RunTestERC20Contract() in main.go.

Run the following command to deploy the Storage contract, store a value in the deployed smart contract and reading the value from the deployed smart contract.

go run main.go

After successfully running this step you should get console output similar to:

You are now connected to Neon EVM Devnet
The NEON balance of the account is: 310387553758242748088682
------------------------------------------------------------------------
Deploying Storage contract...
The contract is deployed at address:  0x6b6Ba862e2bBc0C1305DF681d45f16a1D6F57baf
Transaction hash: 0xf84667ce0bd5d2da4dfcf81fe9c72bdc81c207a41a3c9baa4c43e9ebb6ae1b6e

You are now connected to Neon EVM Devnet
The NEON balance of the account is: 310383249542814769793482
------------------------------------------------------------------------
Storing value in the Storage contract...
Estimated gas: 25000
Transaction hash: 0x24e5af83df1e9f1536d684c08e903d1285f1f5e484df43d4616c925bb25ec9a9

You are now connected to Neon EVM Devnet
The NEON balance of the account is: 310383247282862115123482
------------------------------------------------------------------------
Reading value from the Storage contract...
Returned value: 45

Interact with the TestERC20 smart contract

Generate the go bindings

1. Run the following commands to generate the smart contract ABI and bytecode.

solc --abi ./contracts/TestERC20.sol -o build

solc --bin ./contracts/TestERC20.sol -o build

2. Run the following command to generate the smart contract go binding inside contractsgo folder.

 abigen --abi ./build/TestERC20.abi --pkg contractsgo --type TestERC20 --out ./contractsgo/TestERC20.go --bin ./build/TestERC20.bin

Run the smart contracts functions

Important

To run only the TestERC20 contract, please comment out deploy.RunStorageContract() in main.go.

Run the following command to deploy the TestERC20 contract and transfer some TestERC20 tokens from the deployer address to a randomly created address

go run main.go

After successfully running this step you should get console output similar to:

You are now connected to Neon EVM Devnet
The NEON balance of the account is: 310383247282862115123482
------------------------------------------------------------------------
Deploying TestERC20 contract...
The contract is deployed at address:  0x7BeE8180c4f35744C9cC811e540252ECcD8AcEb4
Transaction hash: 0xf8af65bcb8187bcdcc8c7a5a7106f242c941d6506201497f31f46099d891bcc6

You are now connected to Neon EVM Devnet
The NEON balance of the account is: 310373551028315738437922
------------------------------------------------------------------------
Transferring TestERC20 tokens...
Estimated gas: 1422000
Sender balance before transfer: 1000000000000000000000
Receiver balance before transfer: 0
Transaction hash: 0x8d2ff2a94f836b25e3ae9cc2f9b95ca73e3b3c1e4a6bf7725890eddd915029ab

Sender balance after transfer: 999999999999999999990
Receiver balance after transfer: 10