Moonbeam Playground Solidity

This repository serves to test Smart Contracts written in Solidity on Moonbeam. Moonbeam is a Substrate based Blockchain that aims to become a Ethereum-compatible Parachain on Polkadot.

Github of Moonbeam: https://github.com/PureStake/moonbeam

Moonbeam & Frontier

Moonbeam is integrating Frontier which is Substrate's Ethereum compatibility layer.

What's special about Moonbeam is that it unifies accounts to fully support Ethereum-like H160 addresses and thus eliminates the need for holding two separate private keys in order to make use of Substrate based features and Ethereum features.

Read more:

• https://www.purestake.com/news/moonbeam-network-upgrades-account-structure-to-match-ethereum/
• https://medium.com/moonbeam-network/moonbase-alpha-v3-introducing-unified-accounts-88fae3564cda

Moonbeam Standalone Node

To run the standalone node execute the following command.

docker-compose up -d

Open explorer(s)

To see the activities (e.g. new blocks and other chain events) visit https://polkadot.js.org/apps/?rpc=ws%3A%2F%2F127.00.1%3A9944.

There is also a more specific Ethereum explorer available here https://expedition.dev/?rpcUrl=http%3A%2F%2F127.0.0.1%3A9933

Note: If you are using Brave you should disable the shields in order to get a connection.

Configure Metamask

You can also use Metamask to perform transactions on the local Moonbeam network using following configuration:

• RPC URL: http://127.0.0.1:9933
• ChainID: 1281
• Symbol (Optional): DEV

You can e.g. create a new Account on Metamask and send the coins from Polkadot-JS Apps using the Account tab from the default Account you imported previously to the newly created Account on Metamask to test if it works.

Deploy and test "Incrementer" Contract

Following the official tutorial we can easily deploy and interact with a Smart Contract on Moonbeam. In this case we use solc to compile the Smart Contract and web3 to deploy and interact with the Contract.

1. Switch to folder sample-incrementer-contract
2. Run npm install
   • will install the dependencies solc and web3 which are required to compile and interact with the Smart Contract
3. Run node deploy.js
   • will deploy the Incrementer Contract on the Moonbeam node and print its address
4. Run export CONTRACT_ADDRESS=<?>
   • replace <?> with the actual Contract address
   • this env variable is used in other scripts to interact with the Contract
5. Run node get.js
   • the number should be 51
6. Run node increment.js
   • the number will be increased by 3
   • when running get.js again it should print 54
7. Run node reset.js
   • will set the number to 0

Use Truffle to write, test and deploy Smart Contracts

Moonbeam provides a Truffle box with a sample ERC20 token contract which is already "unboxed" in the folder truffle-box.

Instead of having to run the Moonbeam node using the docker-compose file it is also possible to run it by executing commands with the provided moonbeam-truffle-plugin. You can read more about the Truffle integration at https://docs.moonbeam.network/integrations/trufflebox/.

For playing around with the default box:

1. Switch to folder truffle-box
2. Run npm install to install the required dependencies
3. Run truffle compile to compile the Contract
4. Run truffle test to execute the tests written in Javascript
5. Run truffle migrate --network dev to deploy the Contract on the local node started previously using the compose file

Official documentation

There are lots of other tutorials and informations about Moonbeam. Checkout the official documentation to learn more.