/Doppelganger

Smart contract mocking tool

Primary LanguageJavaScriptMIT LicenseMIT

Doppelganger

doppelgänger /ˈdɒp(ə)lˌɡaŋə,ˈdɒp(ə)lˌɡɛŋə/ - an apparition or double of a living person

Build Status

Library for mocking smart contract dependencies during unit testing.

Install

To start using with npm, type:

npm i -D ethereum-doppelganger

or with Yarn:

yarn add --dev ethereum-doppelganger

Doppelganger is currently developed to work with ethers-js exclusively. Support for other framework will be added in a future version.

Usage

Create a instance of Doppelganger providing the ABI/interface of the smart contract you want to mock:

import Doppelganger from 'ethereum-doppelganger';

...

const doppelganger = new Doppelganger(abi);

Deploy a instance of the Doppelganger smart contract:

await doppelganger.deploy(wallet);

Doppelganger can now be passed into other contracts by using the address attribute.

Return values for mocked functions can be set using:

await doppelganger.<nameOfMethod>.returns(<value>)