Description

This solidity project shows how can invoke functions in deployed smart contract with the function hash.

The ContractParser.js javascript class helps to get the function hashes for a specific ABI.

Get Started

• Download truffle v4.1.13 or up from here

npm install -g truffle

• Execute in the root folder

npm install

• Execute the test cases executing:

truffle test

How do I get set up?

Install NPM Dependencies

Run npm install at the root folder.

Working with Truffle

Once you are located at the root folder, you can execute any truffle command, for instance truffle compile.

How to run tests

In order to can run the tests with Truffle, execute the below command in your project root folder:

truffle test

Smart Contract Details

ERC20Caller

balanceOf(bytes4 _hash, address owner) public

Calls the balanceOf function in the ERC20 injected by constructor.

Arguments:

• _hash function hash to invoke.
• owner address to get the balance of.

function transfer(bytes4 _hash, address _to, uint _value) public

Call the transfer function in the ERC20 instance injected by constructor.

Arguments:

• _hash function hash to invoke.
• _to destination address.
• _value amount of tokens to be transfered.

ExternalContractCaller

function callFunction(bytes4 _functionSignature) public

Call the myFunction function in the smart contract injected by constructor.

Arguments:

• _functionSignature function hash to invoke.

function callFunctionUint(bytes4 _functionSignature, uint _value) public

Call the myOtherFunction function in the smart contract injected by constructor.

Arguments:

• _functionSignature function hash to invoke.
• _value value to pass in the function to invoke.

Mocks and Other Smart Contracts

This project uses some external smart contracts from OpenZeppelin.

• contracts/interface/ERC20.sol
• contracts/interface/ERC20Basic.sol
• contracts/mock/BasicToken.sol
• contracts/mock/StandardToken.sol
• contracts/mock/StandardTokenMock.sol
• contracts/util/SafeMath.sol

You can take the latest version from the URL below:

https://github.com/OpenZeppelin/openzeppelin-solidity

Do you want to contact me?

You can send me an email to guillesalazar@gmail.com.