A mocha reporter for Truffle.

• Gas usage per unit test.
• Average gas usage per method.
• Contract deployment costs.
• Real currency costs.

npm install --save-dev eth-gas-reporter

module.exports = {
  networks: {
    ...etc...
  },
  mocha: {
    reporter: 'eth-gas-reporter',
    reporterOptions : {
      currency: 'CHF',
      gasPrice: 21
    }
  }
};

• gnosis/gnosis-contracts
• windingtree/LifToken

• Requires Node >= 8.
• Method calls that throw are filtered from the stats.
• Not currently shown in the deployments table:
  • Contracts that never get instantiated within the tests (e.g: only deployed in migrations)
  • Contracts that are only ever created by other contracts within Solidity.
• Your ethereum client has to be run in separate process (e.g. reporter will not work if you connect to ganache through a provider in your truffle.js). This because mocha's reporter is sync and we have to collect gas data synchronously from the client as your tests run. Sync requests fail with an in memory provider because they block the thread and prevent a response. (Pro-tip courtesy of @fosgate29).

All the ideas in this utility have been borrowed from elsewhere. Many thanks to:

• @maurelian - Mocha reporting gas instead of time is his idea.
• @cag - The table borrows from / is based his gas statistics work for the Gnosis contracts.
• Neufund - Block limit size ratios for contract deployments and euro pricing are borrowed from their ico-contracts test suite.

• @cgewecke
• @rmuslimov
• @area