Smock is the Solidity mocking library. It's a plugin for
hardhat that can be used to create mock Solidity
contracts entirely in JavaScript (or TypeScript!). With Smock, it's
easier than ever to test your smart contracts. You'll never have to
write another mock contract in Solidity again.
Smock is inspired by sinon,
sinon-chai, and Python's
unittest.mock.
Although Smock is currently only compatible with
hardhat, we plan to extend support to other
testing frameworks like Truffle.
If you wanna chat about the future of Solidity Mocking, join our
Discord!
Features
- Get rid of your folder of "mock" contracts and just use
JavaScript.
- Keep your tests simple with a sweet set of chai matchers.
- Fully compatible with TypeScript and TypeChain.
- Manipulate the behavior of functions on the fly with fakes.
- Modify functions and internal variables of a real contract with
mocks.
- Make assertions about calls, call arguments, and call counts.
- We've got extensive documentation and a complete test suite.
Documentation
Detailed documentation can be found
here.
Quick Start
Installation
You can install Smock via npm or yarn:
npm install @defi-wonderland/smock
Note: Starting from v2.4.0, Smock is only compatible with
Hardhat v2.21.0 or later. If you are using an older version of Hardhat,
please install Smock v2.3.5.
Basic Usage
Smock is dead simple to use. Here's a basic example of how you might use
it to streamline your tests.
...
import { FakeContract, smock } from '@defi-wonderland/smock';
chai.should();
chai.use(smock.matchers);
describe('MyContract', () => {
let myContractFake: FakeContract<MyContract>;
beforeEach(async () => {
...
myContractFake = await smock.fake('MyContract');
});
it('some test', () => {
myContractFake.bark.returns('woof');
...
myContractFake.bark.atCall(0).should.be.calledWith('Hello World');
});
});
License
Smock is released under the MIT license. Feel free to use, modify,
and/or redistribute this software as you see fit. See the
LICENSE
file for more information.
Contributors
Maintained with love by Optimism PBC and DeFi
Wonderland. Made possible by viewers like you.