Solidity unit tests & code coverage with Etherlime

An easy way to test your solidity smart contracts.

Published in

LimeChain

2 min readAug 24, 2018

Written by: Veselin Savov of LimeChain

Hey all, I want to share with you an easy way to test your smart contracts. Currently Ethereum ecosystem is still in development. A lot of tools are still missing. But for our luck there is Etherlime. Now I will show how to write tests and run code coverage with Etherlime.

First you need to install Etherlime. Open your project folder and run this commands.

npm i -g etherlime
etherlime init

Let’s write a simple contract that we will be test.

Write tests

When you open test/exampleTest.js you will find this code

Add some requires.
SimpleContract — path to your compiled contract
ethers — ether js lib
expectThrow — if you have cases where you want expect errors you may copy code from below.

If you are getting out of gas exception you will need to override default gasLimit.

Etherlime passes 10 accounts with million ethers. Each account object contains privateKey and wallet.

Let’t add beforeEach which will be called before test.
EtherlimeGanacheDeployer takes 3 params:
- private key of wallet which will be used to deploy contracts
- port of ganache
- overrideOptions

And this is our first test case.

One more test and full code of exampleTest.js

If you want to call contract from a different account you may use ethers js

var contract = new ethers.Contract(simpleContractDeployed.contract.address, SimpleContract.abi, secondAccount.wallet);

Run tests

To run exampleTest.js you need to start ganache. Open your cmd/terminal and run this command:

etherlime ganache

Open one more cmd/terminal and go to your project directory.
Run etherlime test command. Before each run all contract are recompiled. If you want to compiler to optimize your code pass runs={number}