migration-from-truffle-guide.rst

Migration from Truffle to Etherlime

Install & Initialize Etherlime

npm i -g etherlime

Install the global etherlime to allow you to run etherlime commands.

etherlime init

The command will add to your project structure the following parts:

• ./contracts/LimeFactory.sol
• ./deployment/deploy.js
• ./test/exampleTest.js

Note! These are added just to give you an example. You can remove them.

Write new scripts for deployment using the template provided

• require etherlime module
• require the compiled contract from ./build folder not the contract itself

with Truffle :: const LimeFactory = artifacts.require("./LimeFactory.sol");

with Etherlime :: const etherlime = require('etherlime') const LimeFactory = require('../build/LimeFactory.json');

• set the deployer and then deploy the contract

Local deployment with Etherlime :: const etherlime = require('etherlime') const LimeFactory = require('../build/LimeFactory.json'); const InterfaceFactory = require('../build/InterfaceFactory.json')

const deployer = new etherlime.EtherlimeGanacheDeployer(); const limeFactory = await deployer.deploy(LimeFactory);

//example how to wrap deployed contract and to pass its address const contractInstance = await etherlime.ContractAt(InterfaceFactory, limeFactory.contractAddress)

Find more examples for deployment here.

---

Modify tests

In order to modify the tests from Truffle to Etherlime, slight changes are needed to be done:

with Truffle :: const LimeFactory = artifacts.require("./LimeFactory.sol");

contract('LimeFactory tests', async (accounts) => {

let owner = accounts[0];

beforeEach(async function() {

limeFactory = await LimeFactory.new();

});

it('should do something', () => {

})

}

with Etherlime :: // step1: require Etherlime module const etherlime = require('etherlime')

// step2: require compiled contract from ./build not the .sol file (as in deployment scripts) const LimeFactory = require('../build/LimeFactory.json')

// step4: replace 'contract' descriptor to 'describe' then remove (accounts) param in async function describe('LimeFactory tests', async () => {

// step5: initialize account let owner = accounts[0];

// step6: set the deployer in before/beforeEach and fix the deployment scripts as we did before beforeEach(async function() {

deployer = new etherlime.EtherlimeGanacheDeployer(owner.secretKey); limeFactory = await deployer.deploy(LimeFactory);

});

it('should do something', () => {

})

})

Flexibility

• in case you want to use an address of an account, you must extend it to let owner = accounts[0].signer.address
• when a contract’s method is called, the default sender is set to accounts[0]. If you want to execute it from another account, replace {from: anotherAccount} object with .from(anotherAccount).

with Truffle :: await limeFactory.createLime(newLime' 0, 10, 12, {from: accounts[1]})

with Etherlime :: await limeFactory.from(2).createLime('newLime' 0, 10, 12);

// as a param you may also use: await limeFactory.from(accounts[1]).createLime('newLime' 0, 10, 12); await limeFactory.from(accounts[1].signer).createLime('newLime' 0, 10, 12); await limeFactory.from(accounts[1].signer.address).createLime('newLime' 0, 10, 12); await limeFactory.from(customSigner).createLime('newLime' 0, 10, 12);

• when you need to execute payable function, pass the value as an object contract.somePayableFunction(arg1, arg2, {value: 100})
• don't use “.call” when calling view functions.
• to timeTravel - replace web3 increaseTime with global options utils.timeTravel(provider, seconds)

Assertions and available utils

For more convenience Etherlime provides some additional assertions and global utils object:

assert it is an address :: it('should be valid address', async () => { assert.isAddress(limeFactory.contractAddress, "The contract was not deployed"); })

assert a function revert :: it('should revert if try to create lime with 0 carbohydrates', async () => { let carbohydrates = 0; await assert.revert(limeFactoryInstance.createLime("newLime2", carbohydrates, 8, 2), "Carbohydrates are not set to 0"); });

test an event

with Truffle:

let expectedEvent = 'FreshLime';
let result = await limeFactory.createLime('newLime' 8, 10, 12);
assert.lengthOf(result.logs, 1, "There should be 1 event emitted from new product!");
assert.strictEqual(result.logs[0].event, expectedEvent, `The event emitted was ${result.logs[0].event} instead of ${expectedEvent}`);

with Etherlime

let expectedEvent = 'FreshLime'
let transaction = await limeFactory.createLime('newLime' 8, 10, 12);
const transactionReceipt = await limeFactory.verboseWaitForTransaction(transaction)

// check the transaction has such an event
let isEmitted = utils.hasEvent(transactionReceipt, LimeFactory, expectedEvent);
assert(isEmitted, 'Event FreshLime was not emitted');

// parse logs
let logs = utils.parseLogs(transactionReceipt, LimeFactory, expectedEvent);
assert.equal(logs[0].name, 'newLime, "LimeFactory" with name "newLime" was not created');

Find more test examples here.

---

Final steps:

• delete ./migrations folder
• delete truffle.js/truffle-config.js file
• delete truffle from package.json
• delete node_modules
• run npm install
• open a fresh terminal tab and enter etherlime ganache
• run etherlime test