# Foundry 2 Echidna

The purpose of this tool is to transform the foundry broadcast JSON file to an Etheno-like JSON file for seamless Foundry integration with Echidna.

### Demo

![Demo GIF](https://github.com/ChmielewskiKamil/foundry2echidna/blob/master/Foundry2Echidna%20demo.gif)

### Installation

Make sure you have [Rust installed](https://www.rust-lang.org/tools/install).

Install from crates.io:
`cargo install foundry2echidna`

Install from source:

```shell
git clone https://github.com/ChmielewskiKamil/foundry2echidna/foundry2echidna &&
cd foundry2echidna &&
cargo install --path .
```

### How to use it

Once you have `foundry2echidna` installed, you are ready to transform broadcast files.

1. In the root of your Foundry project, run the command `foundry2echidna`. By default, if no arguments were passed, the tool will look for the following:

  - Your broadcast in `broadcast/*.s.sol/31337/run-latest.json`
  - And will output to `src/crytic/init.json`

  You can pass custom input and output paths like this:

  `foundry2echidna --input-path path/to/broadcast.json --output-path path/to/init.json`

  Or, for short:
  `foundry2echidna -i path/to/broadcast.json -o path/to/init.json`
 

2. Seed Echidna with the generated `init.json` file. Add the following to your `echidna_config.yaml`:

- `initialize: path/to/init.json` (for your custom output path)
- or `initialize: src/crytic/init.json` (for the default output path, if no arguments were provided)

3. Update your `EchidnaTest` contract,
just like you would be interacting with the contracts deployed on the blockchain.

- Get the appropriate contract addresses from the broadcast file generated by Foundry (`run-latest.json`).

```solidity
// Get address of the Counter contract from the broadcast file
counter = Counter(0x1234...);

// This works for contracts deployed by Factories and function calls as well
counterFactory = CounterFactory(0x456...);
anotherCounterDeployedByFactory = AnotherCounter(0x678...);
```

4. Run Echidna.

### Integrate foundry2echinda with your project

[Here you can find dev documentation on docs.rs](https://docs.rs/foundry2echidna/0.1.0/foundry2echidna/).

You can use the `transform_broadcast` function that takes two arguments:

- input_path
- output_path

to deserialize and serialize broadcast files.

---

### Data Model (inner workings)

Etheno handles two main groups of events* (via `EventSummaryPlugin`):

- Contract creations
- Function calls

`ContractCreated` event has the following fields:

- `event` - this is just the name of the type of the event -> `ContractCreated`
- `from` - this is the address of the contract creator
- `contract_address` - deployed contract address
- `gas_used` - the amount of gas used in the transaction
- `gas_price` - gas price used in the transaction
- `data` - transaction data
- `value` - Ether sent in the transaction

`FunctionCall` event has the following fields:

- `event` - this is just the name of the type of the event -> `FunctionCall`
- `from` - address of an account that made the call
- `to` - address of an account that has been called
- `gas_used` - the amount of gas used in the transaction
- `gas_price` - gas price used in the transaction
- `data` - transaction data
- `value` - Ether sent in the transaction

*_There is also block mined event, but it's not crucial for Echidna setup (?)_

Foundry broadcast structure is more complicated than that, but we only care about a couple of fields.
Since we want to transform the broadcast into this Etheno-like structure, the appropriate fields must be mapped together.

| Etheno field | Foundry field |
| --- | --- |
| `event` | `transactions[i].transaction_type` |
| `from` | `transactions[i].transaction.from`|
| `to` |  `transactions[i].transaction.to` |
| `contract_address` |  `transactions[i].contract_address`|
| `gas_used` | `receipts[i].gas_used` |
| `gas_price` | `receipts[i].effective_gas_price` |
| `data` | `transactions[i].transaction.data` |
| `value` | `transactions[i].transaction.value` |