From 63f1742357226e3f7fca468610c4d2fe93f1c3b1 Mon Sep 17 00:00:00 2001
From: Matthias Seitz <matthias.seitz@outlook.de>
Date: Thu, 15 Sep 2022 21:44:52 +0200
Subject: [PATCH] feat(etherscan): add blocked by cloudflare error (#1703)

---
 ethers-etherscan/src/errors.rs |  9 +++++++++
 ethers-etherscan/src/lib.rs    | 18 ++++++++++++++----
 2 files changed, 23 insertions(+), 4 deletions(-)

diff --git a/ethers-etherscan/src/errors.rs b/ethers-etherscan/src/errors.rs
index 060b518f..2ff4d0c6 100644
--- a/ethers-etherscan/src/errors.rs
+++ b/ethers-etherscan/src/errors.rs
@@ -37,4 +37,13 @@ pub enum EtherscanError {
     MissingSolcVersion(String),
     #[error("Invalid API Key")]
     InvalidApiKey,
+    #[error("Sorry, you have been blocked by Cloudflare, See also https://community.cloudflare.com/t/sorry-you-have-been-blocked/110790")]
+    BlockedByCloudflare,
+}
+
+/// etherscan/polyscan is protected by cloudflare, which can lead to html responses like `Sorry, you have been blocked` See also <https://community.cloudflare.com/t/sorry-you-have-been-blocked/110790>
+///
+/// This returns true if the `txt` is a cloudflare error response
+pub(crate) fn is_blocked_by_cloudflare_response(txt: &str) -> bool {
+    txt.to_lowercase().contains("sorry, you have been blocked")
 }
diff --git a/ethers-etherscan/src/lib.rs b/ethers-etherscan/src/lib.rs
index 1f08e0b0..33fd37cf 100644
--- a/ethers-etherscan/src/lib.rs
+++ b/ethers-etherscan/src/lib.rs
@@ -1,5 +1,6 @@
 //! Bindings for [etherscan.io web api](https://docs.etherscan.io/)
 
+use crate::errors::is_blocked_by_cloudflare_response;
 use contract::ContractMetadata;
 use errors::EtherscanError;
 use ethers_core::{
@@ -15,6 +16,7 @@ use std::{
     time::{Duration, SystemTime, UNIX_EPOCH},
 };
 use tracing::{error, trace};
+
 pub mod account;
 pub mod contract;
 pub mod errors;
@@ -168,10 +170,14 @@ impl Client {
             .text()
             .await?;
 
-        Ok(serde_json::from_str(&response).map_err(|err| {
+        serde_json::from_str(&response).map_err(|err| {
             error!(target: "etherscan", ?response, "Failed to deserialize response: {}", err);
-            err
-        })?)
+            if is_blocked_by_cloudflare_response(&response) {
+                EtherscanError::BlockedByCloudflare
+            } else {
+                EtherscanError::Serde(err)
+            }
+        })
     }
 
     /// Execute an API GET request with parameters
@@ -189,7 +195,11 @@ impl Client {
 
         let response: ResponseData<T> = serde_json::from_str(&response).map_err(|err| {
             error!(target: "etherscan", ?response, "Failed to deserialize response: {}", err);
-            err
+            if is_blocked_by_cloudflare_response(&response) {
+                EtherscanError::BlockedByCloudflare
+            } else {
+                EtherscanError::Serde(err)
+            }
         })?;
 
         match response {