ethers-rs/ethers-etherscan/src/lib.rs

513 lines
17 KiB
Rust

#![doc = include_str!("../README.md")]
#![deny(unsafe_code, rustdoc::broken_intra_doc_links)]
use crate::errors::{is_blocked_by_cloudflare_response, is_cloudflare_security_challenge};
use contract::ContractMetadata;
use errors::EtherscanError;
use ethers_core::{
abi::{Abi, Address},
types::{Chain, H256},
};
use reqwest::{header, IntoUrl, Url};
use serde::{de::DeserializeOwned, Deserialize, Serialize};
use std::{
borrow::Cow,
io::Write,
path::PathBuf,
time::{Duration, SystemTime, UNIX_EPOCH},
};
use tracing::{error, trace};
pub mod account;
pub mod contract;
pub mod errors;
pub mod gas;
pub mod source_tree;
pub mod transaction;
pub mod utils;
pub mod verify;
pub(crate) type Result<T> = std::result::Result<T, EtherscanError>;
/// The Etherscan.io API client.
#[derive(Clone, Debug)]
pub struct Client {
/// Client that executes HTTP requests
client: reqwest::Client,
/// Etherscan API key
api_key: Option<String>,
/// Etherscan API endpoint like <https://api(-chain).etherscan.io/api>
etherscan_api_url: Url,
/// Etherscan base endpoint like <https://etherscan.io>
etherscan_url: Url,
/// Path to where ABI files should be cached
cache: Option<Cache>,
}
impl Client {
/// Creates a `ClientBuilder` to configure a `Client`.
///
/// This is the same as `ClientBuilder::default()`.
///
/// # Example
///
/// ```rust
/// use ethers_core::types::Chain;
/// use ethers_etherscan::Client;
/// let client = Client::builder().with_api_key("<API KEY>").chain(Chain::Mainnet).unwrap().build().unwrap();
/// ```
pub fn builder() -> ClientBuilder {
ClientBuilder::default()
}
/// Creates a new instance that caches etherscan requests
pub fn new_cached(
chain: Chain,
api_key: impl Into<String>,
cache_root: Option<PathBuf>,
cache_ttl: Duration,
) -> Result<Self> {
let mut this = Self::new(chain, api_key)?;
this.cache = cache_root.map(|root| Cache::new(root, cache_ttl));
Ok(this)
}
/// Create a new client with the correct endpoints based on the chain and provided API key
pub fn new(chain: Chain, api_key: impl Into<String>) -> Result<Self> {
Client::builder().with_api_key(api_key).chain(chain)?.build()
}
/// Create a new client with the correct endpoints based on the chain and API key
/// from the default environment variable defined in [`Chain`].
pub fn new_from_env(chain: Chain) -> Result<Self> {
let api_key = match chain {
// Extra aliases
Chain::Fantom | Chain::FantomTestnet => std::env::var("FMTSCAN_API_KEY")
.or_else(|_| std::env::var("FANTOMSCAN_API_KEY"))
.map_err(Into::into),
// Backwards compatibility, ideally these should return an error.
Chain::XDai |
Chain::Chiado |
Chain::Sepolia |
Chain::Rsk |
Chain::Sokol |
Chain::Poa |
Chain::Oasis |
Chain::Emerald |
Chain::EmeraldTestnet |
Chain::Evmos |
Chain::EvmosTestnet => Ok(String::new()),
Chain::AnvilHardhat | Chain::Dev => Err(EtherscanError::LocalNetworksNotSupported),
_ => chain
.etherscan_api_key_name()
.ok_or_else(|| EtherscanError::ChainNotSupported(chain))
.and_then(|key_name| std::env::var(key_name).map_err(Into::into)),
}?;
Self::new(chain, api_key)
}
/// Create a new client with the correct endpoints based on the chain and API key
/// from the default environment variable defined in [`Chain`].
///
/// If the environment variable is not set, create a new client without it.
pub fn new_from_opt_env(chain: Chain) -> Result<Self> {
match Self::new_from_env(chain) {
Ok(client) => Ok(client),
Err(EtherscanError::EnvVarNotFound(_)) => {
Self::builder().chain(chain).and_then(|c| c.build())
}
Err(e) => Err(e),
}
}
/// Sets the root to the cache dir and the ttl to use
pub fn set_cache(&mut self, root: impl Into<PathBuf>, ttl: Duration) -> &mut Self {
self.cache = Some(Cache { root: root.into(), ttl });
self
}
pub fn etherscan_api_url(&self) -> &Url {
&self.etherscan_api_url
}
pub fn etherscan_url(&self) -> &Url {
&self.etherscan_url
}
/// Return the URL for the given block number
pub fn block_url(&self, block: u64) -> String {
format!("{}block/{block}", self.etherscan_url)
}
/// Return the URL for the given address
pub fn address_url(&self, address: Address) -> String {
format!("{}address/{address:?}", self.etherscan_url)
}
/// Return the URL for the given transaction hash
pub fn transaction_url(&self, tx_hash: H256) -> String {
format!("{}tx/{tx_hash:?}", self.etherscan_url)
}
/// Return the URL for the given token hash
pub fn token_url(&self, token_hash: Address) -> String {
format!("{}token/{token_hash:?}", self.etherscan_url)
}
/// Execute an GET request with parameters.
async fn get_json<T: DeserializeOwned, Q: Serialize>(&self, query: &Q) -> Result<Response<T>> {
let res = self.get(query).await?;
self.sanitize_response(res)
}
/// Execute a GET request with parameters, without sanity checking the response.
async fn get<Q: Serialize>(&self, query: &Q) -> Result<String> {
trace!(target: "etherscan", "GET {}", self.etherscan_api_url);
let response = self
.client
.get(self.etherscan_api_url.clone())
.header(header::ACCEPT, "application/json")
.query(query)
.send()
.await?
.text()
.await?;
Ok(response)
}
/// Execute a POST request with a form.
async fn post_form<T: DeserializeOwned, F: Serialize>(&self, form: &F) -> Result<Response<T>> {
let res = self.post(form).await?;
self.sanitize_response(res)
}
/// Execute a POST request with a form, without sanity checking the response.
async fn post<F: Serialize>(&self, form: &F) -> Result<String> {
trace!(target: "etherscan", "POST {}", self.etherscan_api_url);
let response = self
.client
.post(self.etherscan_api_url.clone())
.form(form)
.send()
.await?
.text()
.await?;
Ok(response)
}
/// Perform sanity checks on a response and deserialize it into a [Response].
fn sanitize_response<T: DeserializeOwned>(&self, res: impl AsRef<str>) -> Result<Response<T>> {
let res = res.as_ref();
let res: ResponseData<T> = serde_json::from_str(res).map_err(|err| {
error!(target: "etherscan", ?res, "Failed to deserialize response: {}", err);
if res == "Page not found" {
EtherscanError::PageNotFound
} else if is_blocked_by_cloudflare_response(res) {
EtherscanError::BlockedByCloudflare
} else if is_cloudflare_security_challenge(res) {
EtherscanError::CloudFlareSecurityChallenge
} else {
EtherscanError::Serde(err)
}
})?;
match res {
ResponseData::Error { result, .. } => {
if result.starts_with("Max rate limit reached") {
Err(EtherscanError::RateLimitExceeded)
} else if result.to_lowercase() == "invalid api key" {
Err(EtherscanError::InvalidApiKey)
} else {
Err(EtherscanError::Unknown(result))
}
}
ResponseData::Success(res) => Ok(res),
}
}
fn create_query<T: Serialize>(
&self,
module: &'static str,
action: &'static str,
other: T,
) -> Query<T> {
Query {
apikey: self.api_key.as_deref().map(Cow::Borrowed),
module: Cow::Borrowed(module),
action: Cow::Borrowed(action),
other,
}
}
}
#[derive(Clone, Debug, Default)]
pub struct ClientBuilder {
/// Client that executes HTTP requests
client: Option<reqwest::Client>,
/// Etherscan API key
api_key: Option<String>,
/// Etherscan API endpoint like <https://api(-chain).etherscan.io/api>
etherscan_api_url: Option<Url>,
/// Etherscan base endpoint like <https://etherscan.io>
etherscan_url: Option<Url>,
/// Path to where ABI files should be cached
cache: Option<Cache>,
}
// === impl ClientBuilder ===
impl ClientBuilder {
/// Configures the etherscan url and api url for the given chain
///
/// # Errors
///
/// Fails if the chain is not supported by etherscan
pub fn chain(self, chain: Chain) -> Result<Self> {
fn urls(
api: impl IntoUrl,
url: impl IntoUrl,
) -> (reqwest::Result<Url>, reqwest::Result<Url>) {
(api.into_url(), url.into_url())
}
let (etherscan_api_url, etherscan_url) = chain
.etherscan_urls()
.map(|(api, base)| urls(api, base))
.ok_or_else(|| EtherscanError::ChainNotSupported(chain))?;
self.with_api_url(etherscan_api_url?)?.with_url(etherscan_url?)
}
/// Configures the etherscan url
///
/// # Errors
///
/// Fails if the `etherscan_url` is not a valid `Url`
pub fn with_url(mut self, etherscan_url: impl IntoUrl) -> Result<Self> {
self.etherscan_url = Some(ensure_url(etherscan_url)?);
Ok(self)
}
/// Configures the `reqwest::Client`
pub fn with_client(mut self, client: reqwest::Client) -> Self {
self.client = Some(client);
self
}
/// Configures the etherscan api url
///
/// # Errors
///
/// Fails if the `etherscan_api_url` is not a valid `Url`
pub fn with_api_url(mut self, etherscan_api_url: impl IntoUrl) -> Result<Self> {
self.etherscan_api_url = Some(ensure_url(etherscan_api_url)?);
Ok(self)
}
/// Configures the etherscan api key
pub fn with_api_key(mut self, api_key: impl Into<String>) -> Self {
self.api_key = Some(api_key.into()).filter(|s| !s.is_empty());
self
}
/// Configures cache for etherscan request
pub fn with_cache(mut self, cache_root: Option<PathBuf>, cache_ttl: Duration) -> Self {
self.cache = cache_root.map(|root| Cache::new(root, cache_ttl));
self
}
/// Returns a Client that uses this ClientBuilder configuration.
///
/// # Errors
///
/// If the following required fields are missing:
/// - `etherscan_api_url`
/// - `etherscan_url`
pub fn build(self) -> Result<Client> {
let ClientBuilder { client, api_key, etherscan_api_url, etherscan_url, cache } = self;
let client = Client {
client: client.unwrap_or_default(),
api_key,
etherscan_api_url: etherscan_api_url
.ok_or_else(|| EtherscanError::Builder("etherscan api url".to_string()))?,
etherscan_url: etherscan_url
.ok_or_else(|| EtherscanError::Builder("etherscan url".to_string()))?,
cache,
};
Ok(client)
}
}
/// A wrapper around an Etherscan cache object with an expiry
#[derive(Clone, Debug, Deserialize, Serialize)]
struct CacheEnvelope<T> {
expiry: u64,
data: T,
}
/// Simple cache for etherscan requests
#[derive(Clone, Debug)]
struct Cache {
root: PathBuf,
ttl: Duration,
}
impl Cache {
fn new(root: PathBuf, ttl: Duration) -> Self {
Self { root, ttl }
}
fn get_abi(&self, address: Address) -> Option<Option<ethers_core::abi::Abi>> {
self.get("abi", address)
}
fn set_abi(&self, address: Address, abi: Option<&Abi>) {
self.set("abi", address, abi)
}
fn get_source(&self, address: Address) -> Option<Option<ContractMetadata>> {
self.get("sources", address)
}
fn set_source(&self, address: Address, source: Option<&ContractMetadata>) {
self.set("sources", address, source)
}
fn set<T: Serialize>(&self, prefix: &str, address: Address, item: T) {
let path = self.root.join(prefix).join(format!("{address:?}.json"));
let writer = std::fs::File::create(path).ok().map(std::io::BufWriter::new);
if let Some(mut writer) = writer {
let _ = serde_json::to_writer(
&mut writer,
&CacheEnvelope {
expiry: SystemTime::now()
.checked_add(self.ttl)
.expect("cache ttl overflowed")
.duration_since(UNIX_EPOCH)
.expect("system time is before unix epoch")
.as_secs(),
data: item,
},
);
let _ = writer.flush();
}
}
fn get<T: DeserializeOwned>(&self, prefix: &str, address: Address) -> Option<T> {
let path = self.root.join(prefix).join(format!("{address:?}.json"));
let reader = std::io::BufReader::new(std::fs::File::open(path).ok()?);
if let Ok(inner) = serde_json::from_reader::<_, CacheEnvelope<T>>(reader) {
// If this does not return None then we have passed the expiry
if SystemTime::now()
.duration_since(UNIX_EPOCH)
.expect("system time is before unix epoch")
.checked_sub(Duration::from_secs(inner.expiry))
.is_some()
{
return None
}
return Some(inner.data)
}
None
}
}
/// The API response type
#[derive(Debug, Clone, Deserialize)]
pub struct Response<T> {
pub status: String,
pub message: String,
pub result: T,
}
#[derive(Deserialize, Debug, Clone)]
#[serde(untagged)]
pub enum ResponseData<T> {
Success(Response<T>),
Error { status: String, message: String, result: String },
}
/// The type that gets serialized as query
#[derive(Clone, Debug, Serialize)]
struct Query<'a, T: Serialize> {
#[serde(skip_serializing_if = "Option::is_none")]
apikey: Option<Cow<'a, str>>,
module: Cow<'a, str>,
action: Cow<'a, str>,
#[serde(flatten)]
other: T,
}
/// Ensures that the url is well formatted to be used by the Client's functions that join paths.
fn ensure_url(url: impl IntoUrl) -> std::result::Result<Url, reqwest::Error> {
let url_str = url.as_str();
// ensure URL ends with `/`
if url_str.ends_with('/') {
url.into_url()
} else {
into_url(format!("{url_str}/"))
}
}
/// This is a hack to work around `IntoUrl`'s sealed private functions, which can't be called
/// normally.
#[inline]
fn into_url(url: impl IntoUrl) -> std::result::Result<Url, reqwest::Error> {
url.into_url()
}
#[cfg(test)]
mod tests {
use crate::{Client, EtherscanError};
use ethers_core::types::{Address, Chain, H256};
#[test]
fn test_api_paths() {
let client = Client::new(Chain::Goerli, "").unwrap();
assert_eq!(client.etherscan_api_url.as_str(), "https://api-goerli.etherscan.io/api/");
assert_eq!(client.block_url(100), "https://goerli.etherscan.io/block/100");
}
#[test]
fn stringifies_block_url() {
let etherscan = Client::new(Chain::Mainnet, "").unwrap();
let block: u64 = 1;
let block_url: String = etherscan.block_url(block);
assert_eq!(block_url, format!("https://etherscan.io/block/{block}"));
}
#[test]
fn stringifies_address_url() {
let etherscan = Client::new(Chain::Mainnet, "").unwrap();
let addr: Address = Address::zero();
let address_url: String = etherscan.address_url(addr);
assert_eq!(address_url, format!("https://etherscan.io/address/{addr:?}"));
}
#[test]
fn stringifies_transaction_url() {
let etherscan = Client::new(Chain::Mainnet, "").unwrap();
let tx_hash = H256::zero();
let tx_url: String = etherscan.transaction_url(tx_hash);
assert_eq!(tx_url, format!("https://etherscan.io/tx/{tx_hash:?}"));
}
#[test]
fn stringifies_token_url() {
let etherscan = Client::new(Chain::Mainnet, "").unwrap();
let token_hash = Address::zero();
let token_url: String = etherscan.token_url(token_hash);
assert_eq!(token_url, format!("https://etherscan.io/token/{token_hash:?}"));
}
#[test]
fn local_networks_not_supported() {
let err = Client::new_from_env(Chain::Dev).unwrap_err();
assert!(matches!(err, EtherscanError::LocalNetworksNotSupported));
}
}