@drizzle-utils/test-chain

Utils for spawning a test blockchain to run automated tests on.

Usage

Getting started

Install via NPM:

npm install @drizzle-utils/test-chain

Usage example (taken from @drizzle-utils/new-block-stream/__tests__/node_env.js):

/**
 * @jest-environment node
 */
const Web3 = require("web3");
const initTestChain = require("@drizzle-utils/test-chain");

describe("new-block-stream tests in node environment", () => {
  let provider;
  let web3;
  let accounts;
  let contractInstance;

  beforeAll(async () => {
    // Assign results from initTestChain to be accessed by all tests
    ({ provider, web3, accounts, contractInstance } = await initTestChain({
      contract: {
        dirname: __dirname, // contracts folder is a sibling to this .test.js file
        filename: "SimpleStorage.sol",
        contractName: "SimpleStorage",
      },
      ganacheOptions: {
        port: "1234",
      },
    }));
  });

  afterAll(async () => {
    // Make sure to close the provider after all tests are done
    provider.close();
  });

  test("fromPolling can track blocks", async done => {
    // Do your other test stuff up here...

    // Call your contract instance
    await contractInstance.methods.set(0).send({ from: accounts[0] });
    await contractInstance.methods.set(5).send({ from: accounts[0] });
  });
});

API

initTestChain

Intializes the test chain with an optional contract deployed to it.

Parameters

1. options - Object (optional)
   • contract - Object (optional)
     • dirname - String: The directory to search for a contracts folder.
     • filename - String: The Solidity filename.
     • contractName - String: The contract name.
   • ganacheOptions - Object: Ganache options object

Returns

Object

• provider: A web3 provider.
• web3: A web3 instance.
• accounts - String[]: An array of address strings.
• contractInstance: (if contract was specified in options parameter) A web3 contract instance.
• contractArtifact: (if contract was specified in options parameter) The json contract artifact.