eth-saddle

Saddle

Saddle is a simple framework for developing Ethereum Smart Contracts. Think of it like a lean and mean version of truffle.

Philosophy

What saddle does

• Allows you to compile and deploy your contracts.
• Add fast, parallelized tests for your contracts.

** What saddle does not**

• Migrations. It's just "deploy".
• Solidity-language tests
• npm-based Solidity plugins
• solcjs
• complex configuration
• bloat

** What saddle wants to do... one day**

• Smart code coverage (via vm trace's)
• Smart revert messages (e.g. backtraces for Solidity errors)
• Verify your contracts on Etherscan

Installing Saddle

To install saddle, simply create a new npm or yarn project and run:

yarn add eth-saddle
# or
npm install eth-saddle --save

Using Saddle

After you've installed saddle, you can compile, test or deploy your contracts. See saddle help for more information. See configuration below for configuration help.

Let's assume you define a simple Ethereum contract:

contracts/MyContract.sol

pragma solidity ^0.5.9;

contract MyContract {
	function myFunc() pure external returns (uint256) {
		return 55;
	}
}

Now, you can compile your contract with:

npx saddle compile

saddle compile will compile your contracts and store the built output in ./build/contracts.json. This is the raw output of solc compile.

After you've compiled, you can deploy your contracts:

npx saddle deploy -n development

This will deploy your comiled contracts to development (for this, you should have ganache running). For more information on configuring your deployment for rinkeby or mainnet, see the configuration section below.

After you have deployed, you will also see the contract address listed in ./build/development.json, if you want to keep track of your deployments.

Testing Smart Contracts

Note: before testing, you currently have to compile your contracts. To run your tests, then, run:

npx saddle compile && npx saddle test

saddle test runs your tests. To add tests, create a directory /tests and add some simple tests, e.g.

tests/MyTest.js

describe('View', () => {
  test('deploy and read contract', async () => {
    let ctx = await deploy('MyContract', []);

    expect(await call(ctx.methods.myFunc())).toEqual(55);
  });
}

Saddle provides a few helper functions for your tests, which are:

• web3 - A web3 instance connected to the chosen provider
• account - The default account for web3
• accounts - A list of unlocked accounts for web3
• deploy(contract: string, args: any[], sendOptions: SendOptions={}) - Deploys a contract
• call(callable, callOptions: CallOptions={}) - Call a function on a contract
• send(sendable, sendOptions: SendOptions={}) - Send a transaction on a contract

You can really get by without using most of these functions (except maybe deploy), since they are light wrappers around web3 functions, but the wrappers will allow saddle to provide better helpers and diagnostics in the future.

Configuration

Saddle comes with reasonable default configuration, but you can override it. The core of the configuration is a list of "sources" for any given configuration-item, allowing the framework to look at say an environment variable for a provider, or if that is missing, a file with the provider information, or if that is missing, use a default http endpoint. This would be described as:

...
provider: [{env: "PROVIDER"}, {file: "~/.ethereum-provider"}, {http: "http://rinkeby.infura.io"}]

To set your own configuration, simply run: saddle init and this will create a file saddle.config.js. Make any changes to the configuration you need in that file

Contributing

Please create an issue for any questions. In the interest of keeping saddle as simple as possible, we will not try to mimic all features of more complex frameworks-- so it's better to discuss first before submitting PRs.

Thanks and enjoy!