fix(provider): Prevent panic from having 0 keys when calling on_anvil_with_wallet_and_config

crates/node-bindings/src/anvil.rs

@@ -119,6 +119,10 @@ pub enum AnvilError {
     /// An error occurred while parsing a hex string.
     #[error(transparent)]
     FromHexError(#[from] hex::FromHexError),
+
+    /// No keys available in anvil instance.
+    #[error("no keys available in anvil instance")]
+    NoKeysAvailable,
 }
 
 /// Builder for launching `anvil`.

crates/provider/src/builder.rs

@@ -10,7 +10,6 @@ use alloy_chains::NamedChain;
 use alloy_network::{Ethereum, Network};
 use alloy_primitives::ChainId;
 use alloy_rpc_client::{BuiltInConnectionString, ClientBuilder, RpcClient};
-
 use alloy_transport::{BoxTransport, Transport, TransportError, TransportResult};
 use std::marker::PhantomData;
 
@@ -347,6 +346,11 @@ impl<L, F, N> ProviderBuilder<L, F, N> {
     }
 }
 
+type JoinedEthereumWalletFiller<F> = JoinFill<F, WalletFiller<alloy_network::EthereumWallet>>;
+
+#[cfg(any(test, feature = "anvil-node"))]
+type AnvilProviderResult<T> = Result<T, alloy_node_bindings::anvil::AnvilError>;
+
 // Enabled when the `anvil` feature is enabled, or when both in test and the
 // `reqwest` feature is enabled.
 #[cfg(any(test, feature = "anvil-node"))]
@@ -372,7 +376,7 @@ impl<L, F> ProviderBuilder<L, F, Ethereum> {
     /// use in tests.
     pub fn on_anvil_with_wallet(
         self,
-    ) -> <JoinFill<F, WalletFiller<alloy_network::EthereumWallet>> as ProviderLayer<
+    ) -> <JoinedEthereumWalletFiller<F> as ProviderLayer<
         L::Provider,
         alloy_transport_http::Http<reqwest::Client>,
     >>::Provider
@@ -413,17 +417,42 @@ impl<L, F> ProviderBuilder<L, F, Ethereum> {
         self.layer(anvil_layer).on_http(url)
     }
 
-    /// Build this provider with anvil, using an Reqwest HTTP transport. The
-    /// given function is used to configure the anvil instance. This
-    /// function configures a wallet backed by anvil keys, and is intended for
-    /// use in tests.
+    /// Build this provider with anvil, using an Reqwest HTTP transport.
+    /// This calls `try_on_anvil_with_wallet_and_config` and panics on error.
     pub fn on_anvil_with_wallet_and_config(
         self,
         f: impl FnOnce(alloy_node_bindings::Anvil) -> alloy_node_bindings::Anvil,
-    ) -> <JoinFill<F, WalletFiller<alloy_network::EthereumWallet>> as ProviderLayer<
+    ) -> <JoinedEthereumWalletFiller<F> as ProviderLayer<
         L::Provider,
         alloy_transport_http::Http<reqwest::Client>,
     >>::Provider
+    where
+        F: TxFiller<Ethereum>
+            + ProviderLayer<L::Provider, alloy_transport_http::Http<reqwest::Client>, Ethereum>,
+        L: crate::builder::ProviderLayer<
+            crate::layers::AnvilProvider<
+                crate::provider::RootProvider<alloy_transport_http::Http<reqwest::Client>>,
+                alloy_transport_http::Http<reqwest::Client>,
+            >,
+            alloy_transport_http::Http<reqwest::Client>,
+        >,
+    {
+        self.try_on_anvil_with_wallet_and_config(f).unwrap()
+    }
+
+    /// Build this provider with anvil, using an Reqwest HTTP transport. The
+    /// given function is used to configure the anvil instance. This
+    /// function configures a wallet backed by anvil keys, and is intended for
+    /// use in tests.
+    pub fn try_on_anvil_with_wallet_and_config(
+        self,
+        f: impl FnOnce(alloy_node_bindings::Anvil) -> alloy_node_bindings::Anvil,
+    ) -> AnvilProviderResult<
+        <JoinedEthereumWalletFiller<F> as ProviderLayer<
+            L::Provider,
+            alloy_transport_http::Http<reqwest::Client>,
+        >>::Provider,
+    >
     where
         F: TxFiller<Ethereum>
             + ProviderLayer<L::Provider, alloy_transport_http::Http<reqwest::Client>, Ethereum>,
@@ -439,7 +468,9 @@ impl<L, F> ProviderBuilder<L, F, Ethereum> {
         let url = anvil_layer.endpoint_url();
 
         let default_keys = anvil_layer.instance().keys().to_vec();
-        let (default_key, remaining_keys) = default_keys.split_first().expect("no keys available");
+        let (default_key, remaining_keys) = default_keys
+            .split_first()
+            .ok_or(alloy_node_bindings::anvil::AnvilError::NoKeysAvailable)?;
 
         let default_signer = alloy_signer_local::LocalSigner::from(default_key.clone());
         let mut wallet = alloy_network::EthereumWallet::from(default_signer);
@@ -448,7 +479,7 @@ impl<L, F> ProviderBuilder<L, F, Ethereum> {
             wallet.register_signer(alloy_signer_local::LocalSigner::from(key.clone()))
         });
 
-        self.wallet(wallet).layer(anvil_layer).on_http(url)
+        Ok(self.wallet(wallet).layer(anvil_layer).on_http(url))
     }
 }