Make corepc-node optional in payjoin-test-utils

Test constants (ORIGINAL_PSBT, EXAMPLE_URL, etc.) and the
TestServices infrastructure don't require bitcoind. Only
init_bitcoind* functions need the corepc-node crate, which
downloads a ~40MB binary at build time.

Gate corepc-node behind a `bitcoind` feature (default = on)
so downstream consumers can import payjoin-test-utils for
constants without triggering the bitcoind download. This
unblocks nix environments and CI setups that provide their
own bitcoind via BITCOIND_EXE.

Author: DanGould

payjoin-test-utils/Cargo.toml

@@ -8,10 +8,14 @@ repository = "https://github.com/payjoin/rust-payjoin"
 rust-version = "1.85"
 license = "MIT"
 
+[features]
+default = ["bitcoind"]
+bitcoind = ["dep:corepc-node"]
+
 [dependencies]
 axum-server = { version = "0.8", features = ["tls-rustls-no-provider"] }
 bitcoin = { version = "0.32.7", features = ["base64"] }
-corepc-node = { version = "0.10.0", features = ["download", "29_0"] }
+corepc-node = { version = "0.10.0", features = ["download", "29_0"], optional = true }
 http = "1.3.1"
 ohttp = { package = "bitcoin-ohttp", version = "0.6.0" }
 once_cell = "1.21.3"

payjoin-test-utils/src/lib.rs

@@ -4,9 +4,7 @@ use std::sync::Arc;
 use std::time::Duration;
 
 use axum_server::tls_rustls::RustlsConfig;
-use bitcoin::{Amount, Psbt};
-pub use corepc_node; // re-export for convenience
-use corepc_node::AddressType;
+use bitcoin::Psbt;
 use http::StatusCode;
 use ohttp::hpke::{Aead, Kdf, Kem};
 use ohttp::{KeyId, SymmetricSuite};
@@ -19,9 +17,17 @@ use rustls::pki_types::CertificateDer;
 use rustls::RootCertStore;
 use tempfile::tempdir;
 use tokio::task::JoinHandle;
-use tracing::Level;
 use tracing_subscriber::{EnvFilter, FmtSubscriber};
 
+#[cfg(feature = "bitcoind")]
+use bitcoin::Amount;
+#[cfg(feature = "bitcoind")]
+pub use corepc_node;
+#[cfg(feature = "bitcoind")]
+use corepc_node::AddressType;
+#[cfg(feature = "bitcoind")]
+use tracing::Level;
+
 pub type BoxError = Box<dyn std::error::Error + 'static>;
 pub type BoxSendSyncError = Box<dyn std::error::Error + Send + Sync>;
 
@@ -173,6 +179,7 @@ pub fn local_cert_key() -> rcgen::CertifiedKey<rcgen::KeyPair> {
         .expect("Failed to generate cert")
 }
 
+#[cfg(feature = "bitcoind")]
 pub fn init_bitcoind() -> Result<corepc_node::Node, BoxError> {
     let bitcoind_exe = corepc_node::exe_path()?;
     let mut conf = corepc_node::Conf::default();
@@ -182,6 +189,7 @@ pub fn init_bitcoind() -> Result<corepc_node::Node, BoxError> {
     Ok(bitcoind)
 }
 
+#[cfg(feature = "bitcoind")]
 pub fn init_bitcoind_sender_receiver(
     sender_address_type: Option<AddressType>,
     receiver_address_type: Option<AddressType>,
@@ -197,6 +205,7 @@ pub fn init_bitcoind_sender_receiver(
     Ok((bitcoind, receiver, sender))
 }
 
+#[cfg(feature = "bitcoind")]
 fn create_and_fund_wallets<W: AsRef<str>>(
     bitcoind: &corepc_node::Node,
     wallets: Vec<(W, Option<AddressType>)>,
@@ -231,6 +240,7 @@ pub fn http_agent(cert_der: Vec<u8>) -> Result<Client, BoxSendSyncError> {
     Ok(http_agent_builder(cert_der).build()?)
 }
 
+#[cfg(feature = "bitcoind")]
 pub fn init_bitcoind_multi_sender_single_reciever(
     number_of_senders: usize,
 ) -> Result<(corepc_node::Node, Vec<corepc_node::Client>, corepc_node::Client), BoxError> {