cast/cmd/
constructor_args.rs

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1use super::{
2    creation_code::fetch_creation_code,
3    interface::{fetch_abi_from_etherscan, load_abi_from_file},
4};
5use alloy_dyn_abi::DynSolType;
6use alloy_primitives::{Address, Bytes};
7use alloy_provider::Provider;
8use clap::{command, Parser};
9use eyre::{eyre, OptionExt, Result};
10use foundry_block_explorers::Client;
11use foundry_cli::{
12    opts::{EtherscanOpts, RpcOpts},
13    utils::{self, LoadConfig},
14};
15
16/// CLI arguments for `cast creation-args`.
17#[derive(Parser)]
18pub struct ConstructorArgsArgs {
19    /// An Ethereum address, for which the bytecode will be fetched.
20    contract: Address,
21
22    /// Path to file containing the contract's JSON ABI. It's necessary if the target contract is
23    /// not verified on Etherscan
24    #[arg(long)]
25    abi_path: Option<String>,
26
27    #[command(flatten)]
28    etherscan: EtherscanOpts,
29
30    #[command(flatten)]
31    rpc: RpcOpts,
32}
33
34impl ConstructorArgsArgs {
35    pub async fn run(self) -> Result<()> {
36        let Self { contract, mut etherscan, rpc, abi_path } = self;
37
38        let config = rpc.load_config()?;
39        let provider = utils::get_provider(&config)?;
40        let api_key = etherscan.key().unwrap_or_default();
41        let chain = provider.get_chain_id().await?;
42        etherscan.chain = Some(chain.into());
43        let client = Client::new(chain.into(), api_key)?;
44
45        let bytecode = fetch_creation_code(contract, client, provider).await?;
46
47        let args_arr = parse_constructor_args(bytecode, contract, &etherscan, abi_path).await?;
48        for arg in args_arr {
49            let _ = sh_println!("{arg}");
50        }
51
52        Ok(())
53    }
54}
55
56/// Fetches the constructor arguments values and types from the creation bytecode and ABI.
57async fn parse_constructor_args(
58    bytecode: Bytes,
59    contract: Address,
60    etherscan: &EtherscanOpts,
61    abi_path: Option<String>,
62) -> Result<Vec<String>> {
63    let abi = if let Some(abi_path) = abi_path {
64        load_abi_from_file(&abi_path, None)?
65    } else {
66        fetch_abi_from_etherscan(contract, etherscan).await?
67    };
68
69    let abi = abi.into_iter().next().ok_or_eyre("No ABI found.")?;
70    let (abi, _) = abi;
71
72    let constructor = abi.constructor.ok_or_else(|| eyre!("No constructor found."))?;
73
74    if constructor.inputs.is_empty() {
75        return Err(eyre!("No constructor arguments found."));
76    }
77
78    let args_size = constructor.inputs.len() * 32;
79    let args_bytes = Bytes::from(bytecode[bytecode.len() - args_size..].to_vec());
80
81    let display_args: Vec<String> = args_bytes
82        .chunks(32)
83        .enumerate()
84        .map(|(i, arg)| {
85            format_arg(&constructor.inputs[i].ty, arg).expect("Failed to format argument.")
86        })
87        .collect();
88
89    Ok(display_args)
90}
91
92fn format_arg(ty: &str, arg: &[u8]) -> Result<String> {
93    let arg_type: DynSolType = ty.parse().expect("Invalid ABI type.");
94    let decoded = arg_type.abi_decode(arg)?;
95    let bytes = Bytes::from(arg.to_vec());
96
97    Ok(format!("{bytes} → {decoded:?}"))
98}
cast/cmd/constructor_args.rs

cast/cmd/
constructor_args.rs
