Hands-On Smart Contract Development with Solidity and Ethereum

Chapter 7. FundraiserFactory

In the last chapter, we created the Fundraiser contract and implemented the functionality to support creating donations and withdrawing funds. The Fundraiser contract has a lot of functionality, but currently it has no means of being created. In this chapter, we are going to add the contract that will create the individual instances of Fundraiser using a pattern that is likely familiar: the Factory pattern.

At the end of the chapter, we will also walk through grabbing the UI from the GitHub repo and deploying to Ganache. Once it has been deployed, we can launch the app in our browser, create new fundraisers, make donations, and withdraw the funds.

Migrating Our FundraiserFactory

Our Fundraiser contract from the last chapter was designed with the idea that it would be initialized from another contract, the FundraiserFactory, and therefore did not require its own migration. The FundraiserFactory, however, will need to be deployed so that our users can interact with the factory and create their own fundraisers.

Create a new file in the test directory using the following command:

$ touch test/fundraiser_factory_test.js

Let’s add a deployment test case to our new file:

const FundraiserFactoryContract = artifacts.require("FundraiserFactory");

contract("FundraiserFactory: deployment", () => {
  it("has been deployed", async () => {
    const fundraiserFactory = FundraiserFactoryContract.deployed();
    assert(fundraiserFactory, "fundraiser factory was not deployed" ...