Truffle cost

This module allows to log used gas of transactions in your Truffle tests, and optionally price in fiat.

Usage

Works with Truffle v5 and v4!

1) Install

yarn add truffle-cost

(or npm instead of yarn)

2) Edit truffle-config.js / truffle.js

For Truffle v4, add a mocha section to your truffle.js /truffle-config.js. For Truffle v5, it already exists.

In the mocha section, use the reporter mocha-truffle-reporter:

mocha: {
  reporter: "mocha-truffle-reporter"
},

3) Use in your Truffle tests

Add it on top of your .js test:

const truffleCost = require('truffle-cost');

Use it like this:

result = await truffleCost.log(
  yourContract.yourFunction()
);

In result you will have the same thing as if you just did

result = await yourContract.yourFunction();

To have the price in fiat, as well, add one of these fiat symbols: 'USD', 'EUR', 'RUR' or 'GBP':

result = await truffleCost.log(
  yourContract.yourFunction(),
  'USD'
);

You can also use from without any problem and of course just await:

await truffleCost.log(
  yourContract.yourFunction({from: accounts[1]})
);

Colors

The colors are defined in the (Mocha reporter)[https://github.com/guix77/mocha-truffle-reporter/blob/81a482e0f111b3404bd01c294fc40c3f29292407/lib/reporters/truffle-cost.js#L47] and depend on the used gas:

• below 100000: green
• above 4700000: red
• in-between: yellow

Examples

• Truffle 5
• Truffle 4

Limitations

• If you add a fiat symbol, at the beginning of each test truffle-cost will have to make 2 API calls (EthgasStation to get the gas price and Cryptonator to get the Ether price in your fiat. Those prices are then cached, but you need a connection to fetch them once, and it can slow down your tests.

• Cryptonator's API only has USD, EUR, RUR and GBP. I'd be interested in knowing a public API that has more currencies and ideally, which would allow to get all prices and the Ether gas price in one call.

• truffleCost does not work for all Truffle test commands, for instance it can not return a Truffle contract. This will fail:

  const myContract = await truffleCost.log( MyContract.new() );

• In the same test, if you log more the cost, only the last will be taken into account.

Donations

Donations in Ethereum and / or tokens are warmly accepted if you use and like this project:

0x3e486ad2ca1e5b4a9b9088a1126f2961325aeaa7