feat(provider): expose ProviderBuilder via fn builder() (#858)

* feat(provider): expose `ProviderBuilder` via `fn builder()`

* feat(provider): free builder<N>() fn

* nit

* AnyNetwork test for builder fn

crates/provider/src/lib.rs

@@ -40,7 +40,8 @@ pub use heart::{PendingTransaction, PendingTransactionBuilder, PendingTransactio
 
 mod provider;
 pub use provider::{
-    EthCall, FilterPollerBuilder, Provider, RootProvider, RpcWithBlock, SendableTx, WalletProvider,
+    builder, EthCall, FilterPollerBuilder, Provider, RootProvider, RpcWithBlock, SendableTx,
+    WalletProvider,
 };
 
 pub mod utils;

crates/provider/src/provider/mod.rs

@@ -2,7 +2,7 @@ mod call;
 pub use call::EthCall;
 
 mod root;
-pub use root::RootProvider;
+pub use root::{builder, RootProvider};
 
 mod sendable;
 pub use sendable::SendableTx;

crates/provider/src/provider/root.rs

@@ -1,6 +1,7 @@
 use crate::{
     chain::ChainStreamPoller,
     heart::{Heartbeat, HeartbeatHandle},
+    Identity, ProviderBuilder,
 };
 use alloy_network::{Ethereum, Network};
 use alloy_rpc_client::{BuiltInConnectionString, ClientBuilder, ClientRef, RpcClient, WeakClient};
@@ -36,6 +37,12 @@ impl<T: fmt::Debug, N> fmt::Debug for RootProvider<T, N> {
     }
 }
 
+/// Helper function to directly access [`ProviderBuilder`] with minimal
+/// generics.
+pub fn builder<N: Network>() -> ProviderBuilder<Identity, Identity, N> {
+    ProviderBuilder::default()
+}
+
 #[cfg(feature = "reqwest")]
 impl<N: Network> RootProvider<Http<reqwest::Client>, N> {
     /// Creates a new HTTP root provider from the given URL.

crates/provider/src/provider/trait.rs

@@ -2,8 +2,8 @@
 
 use crate::{
     utils::{self, Eip1559Estimation, EstimatorFunction},
-    EthCall, PendingTransaction, PendingTransactionBuilder, PendingTransactionConfig, RootProvider,
-    RpcWithBlock, SendableTx,
+    EthCall, Identity, PendingTransaction, PendingTransactionBuilder, PendingTransactionConfig,
+    ProviderBuilder, RootProvider, RpcWithBlock, SendableTx,
 };
 use alloy_eips::eip2718::Encodable2718;
 use alloy_json_rpc::{RpcError, RpcParam, RpcReturn};
@@ -70,6 +70,14 @@ pub trait Provider<T: Transport + Clone = BoxTransport, N: Network = Ethereum>:
     /// Returns the root provider.
     fn root(&self) -> &RootProvider<T, N>;
 
+    /// Returns the [`ProviderBuilder`](crate::ProviderBuilder) to build on.
+    fn builder() -> ProviderBuilder<Identity, Identity, N>
+    where
+        Self: Sized,
+    {
+        ProviderBuilder::default()
+    }
+
     /// Returns the RPC client used to send requests.
     ///
     /// NOTE: this method should not be overridden.
@@ -948,7 +956,8 @@ impl<T: Transport + Clone, N: Network> Provider<T, N> for RootProvider<T, N> {
 #[cfg(test)]
 mod tests {
     use super::*;
-    use crate::{ProviderBuilder, WalletProvider};
+    use crate::{builder, ProviderBuilder, WalletProvider};
+    use alloy_network::AnyNetwork;
     use alloy_node_bindings::Anvil;
     use alloy_primitives::{address, b256, bytes};
     use alloy_rpc_types_eth::request::TransactionRequest;
@@ -957,6 +966,33 @@ mod tests {
         let _ = tracing_subscriber::fmt::try_init();
     }
 
+    #[tokio::test]
+    async fn test_provider_builder() {
+        init_tracing();
+        let provider =
+            RootProvider::<BoxTransport, Ethereum>::builder().with_recommended_fillers().on_anvil();
+        let num = provider.get_block_number().await.unwrap();
+        assert_eq!(0, num);
+    }
+
+    #[tokio::test]
+    async fn test_builder_helper_fn() {
+        init_tracing();
+        let provider = builder().with_recommended_fillers().on_anvil();
+        let num = provider.get_block_number().await.unwrap();
+        assert_eq!(0, num);
+    }
+
+    #[tokio::test]
+    async fn test_builder_helper_fn_any_network() {
+        init_tracing();
+        let anvil = Anvil::new().spawn();
+        let provider =
+            builder::<AnyNetwork>().with_recommended_fillers().on_http(anvil.endpoint_url());
+        let num = provider.get_block_number().await.unwrap();
+        assert_eq!(0, num);
+    }
+
     #[cfg(feature = "reqwest")]
     #[tokio::test]
     async fn object_safety() {