Library for writing and testing smart contracts.

Sweeter, simpler, faster. Works with ethers-js. Documentation available here.

Philosophy

• Simpler: minimalistic, a couple of helpers, matchers and tasks rather than a framework, few dependencies.
• Sweeter: Nice syntax, fast, easy to extend.
• Faster: Focus on the speed of tests execution, the goal is to have subsecond feedback loop when doing TDD with smart contracts.

Versions and ethers compatibility

• Use version 0.2.3+ with ethers 3.* and solidity 4.*
• Use version 1.0.0+ with ethers 4.* and solidity 4.*
• Use version 2.0.5-beta with ethers 4.*; solidity 4, 5 and to use experimental native solc and dockerized solc.

Install:

To start using with npm, type:

npm i ethereum-waffle

or with Yarn:

yarn add ethereum-waffle

Step by step guide

Example contract

Below is example contract written in Solidity. Place it in contracts directory of your project:

pragma solidity ^0.5.1;

import "../BasicToken.sol";

contract BasicTokenMock is BasicToken {

  constructor(address initialAccount, uint256 initialBalance) public {
    balances[initialAccount] = initialBalance;
    totalSupply_ = initialBalance;
  }

}

Example test

Belows is example test written for the contract above written with Waffle. Place it in test directory of your project:

import chai from 'chai';
import {createMockProvider, deployContract, getWallets, solidity} from 'ethereum-waffle';
import BasicTokenMock from './build/BasicTokenMock';

chai.use(solidity);

const {expect} = chai;

describe('Example', () => {
  let provider;
  let token;
  let wallet;
  let walletTo;

  beforeEach(async () => {
    provider = createMockProvider();
    [wallet, walletTo] = await getWallets(provider);
    token = await deployContract(wallet, BasicTokenMock, [wallet.address, 1000]);
  });

  it('Assigns initial balance', async () => {
    expect(await token.balanceOf(wallet.address)).to.eq(1000);
  });

  it('Transfer adds amount to destination account', async () => {
    await token.transfer(walletTo.address, 7);
    expect(await token.balanceOf(wallet.address)).to.eq(993);
    expect(await token.balanceOf(walletTo.address)).to.eq(7);
  });

  it('Transfer emits event', async () => {
    await expect(token.transfer(walletTo.address, 7))
      .to.emit(token, 'Transfer')
      .withArgs(wallet.address, walletTo.address, 7);
  });

  it('Can not transfer from empty account', async () => {
    const tokenFromOtherWallet = contractWithWallet(token, walletTo);
    await expect(tokenFromOtherWallet.transfer(wallet.address, 1))
      .to.be.revertedWith('Not enough balance on sender account');
  });
});

Compile

To compile contracts simply type:

npx waffle

To compile using custom configuration file:

npx waffle config.json

Example configuration file looks like this:

{
  "sourcesPath": "./custom_contracts",
  "targetPath": "./custom_build",
  "npmPath": "./custom_node_modules"
}

Run tests

To run test type in the console:

mocha

Adding a task

For convince, you can add a task to your package.json. In the sections scripts, add following line:

  "test": "waffle && test"

Now you can build and test your contracts with one command:

npm test

Documentation

For detailed feature walkthrough checkout documentation.

Contributing

Contributions are always welcome, no matter how large or small. Before contributing, please read the code of conduct and contribution policy.

Before you issue pull request:

Make sure all tests and linters pass. Make sure you have test coverage for any new features.

Running tests

Note: To make end to end test pass, you need to:

• have docker installed, up and running
• have native solidity 0.5.* installed

To run tests type:

yarn test

To run linter type:

yarn lint

License

Universal Login SDK is released under the MIT License.

Roadmap

• New matcher: changeBalance (see #9)
• Faster testing with native geth (aside from ganache)
• Faster compilation with native and dockerized solc (aside from solcjs)
• Documentation
• Debugging and profiling