feat(client): implement Client::get_prune_height

Implement `Client::get_prune_height`, returning:
  - `None`, if `bitcoind` is not pruned,
  - `Some(u32)` with the prune height, if `bitcoind` is pruned,

This information is sourced from `getblockchaininfo`.

Author: luisschwab

src/client.rs

@@ -263,6 +263,25 @@ impl Client {
             self.call("getblock", &[json!(block_hash), json!(1)])?;
         block_info.into_model().map_err(Error::GetBlockVerboseOne)
     }
+
+    /// Retrives the prune height of the `bitcoind` instance this client is connected to.
+    ///
+    /// # Returns
+    ///
+    /// The prune height of the `bitcoind` instance, as an `Option<u32>`.
+    pub fn get_prune_height(&self) -> Result<Option<u32>, Error> {
+        let res = {
+            let res: v30::GetBlockchainInfo = self.call("getblockchaininfo", &[])?;
+            res.into_model().map_err(Error::GetBlockchainInfo)?
+        };
+
+        match res.pruned {
+            true => Ok(Some(
+                res.prune_height.expect("pruned=true implies a pruneheight"),
+            )),
+            false => Ok(None),
+        }
+    }
 }
 
 #[cfg(test)]

src/client/v28.rs

@@ -44,4 +44,23 @@ impl Client {
             self.call("getblock", &[json!(block_hash), json!(1)])?;
         block_info.into_model().map_err(Error::GetBlockVerboseOne)
     }
+
+    /// Retrives the prune height of the `bitcoind` instance this client is connected to.
+    ///
+    /// # Returns
+    ///
+    /// The prune height of the `bitcoind` instance, as an `Option<u32>`.
+    pub fn get_prune_height(&self) -> Result<Option<u32>, Error> {
+        let res = {
+            let res: v28::GetBlockchainInfo = self.call("getblockchaininfo", &[])?;
+            res.into_model().map_err(Error::GetBlockchainInfo)?
+        };
+
+        match res.pruned {
+            true => Ok(Some(
+                res.prune_height.expect("pruned=true implies a pruneheight"),
+            )),
+            false => Ok(None),
+        }
+    }
 }

src/error.rs

@@ -3,8 +3,12 @@
 use bitcoin::{consensus::encode::FromHexError, hex::HexToArrayError};
 #[cfg(feature = "28_0")]
 use corepc_types::v17::{GetBlockHeaderVerboseError, GetBlockVerboseOneError};
+#[cfg(feature = "28_0")]
+use corepc_types::v19::GetBlockchainInfoError;
 #[cfg(not(feature = "28_0"))]
-use corepc_types::v30::{GetBlockHeaderVerboseError, GetBlockVerboseOneError};
+use corepc_types::v30::{
+    GetBlockHeaderVerboseError, GetBlockVerboseOneError, GetBlockchainInfoError,
+};
 use corepc_types::{bitcoin, v30::GetBlockFilterError};
 use jsonrpc::serde_json;
 use std::{fmt, io, num::TryFromIntError};
@@ -27,6 +31,9 @@ pub enum Error {
     /// Error modeling [`GetBlockFilter`](corepc_types::model::GetBlockFilter)
     GetBlockFilter(GetBlockFilterError),
 
+    /// Error modeling [`GetBlockchainInfo`](corepc_types::model::GetBlockchainInfo).
+    GetBlockchainInfo(GetBlockchainInfoError),
+
     /// Invalid or corrupted cookie file.
     InvalidCookieFile,
 
@@ -56,6 +63,7 @@ impl fmt::Display for Error {
             Error::GetBlockVerboseOne(e) => write!(f, "block verbose error: {e}"),
             Error::GetBlockHeaderVerbose(e) => write!(f, "block header verbose error: {e}"),
             Error::GetBlockFilter(e) => write!(f, "block filter error: {e}"),
+            Error::GetBlockchainInfo(e) => write!(f, "getblockchaininfo error: {e}"),
             Error::InvalidCookieFile => write!(f, "invalid or missing cookie file"),
             Error::InvalidUrl(e) => write!(f, "invalid RPC URL: {e}"),
             Error::HexToArray(e) => write!(f, "hash parsing error: {e}"),

tests/test_rpc_client.rs

@@ -3,6 +3,7 @@
 //! These tests require a running Bitcoin Core node in regtest mode. To setup refer to [`corepc_node`].
 
 use bdk_bitcoind_client::{Auth, Client, Error};
+use corepc_node::Conf;
 use corepc_types::bitcoin::{Amount, BlockHash, Txid};
 use std::str::FromStr;
 
@@ -306,3 +307,36 @@ fn test_get_block_filter() {
 
     assert!(!result.filter.is_empty());
 }
+
+#[test]
+fn test_get_prune_height() {
+    // Spawn an unpruned node.
+    let env_unpruned = TestEnv::new();
+
+    // Assert that `getblockchaininfo.pruned` is `None`.
+    let unpruned_res = env_unpruned.client.get_prune_height().unwrap();
+    assert_eq!(unpruned_res, None);
+
+    // Spawn a node with manual pruning enabled.
+    let mut node_config = Conf::default();
+    node_config.args.push("-prune=1");
+    node_config.args.push("-fastprune");
+    let env_pruned = TestEnv::new_with_config(&node_config);
+
+    // Mine 1000 blocks.
+    let block_count = 1000;
+    let _hashes = env_pruned.mine_blocks(block_count as usize, None);
+
+    // Assert that `getblockchaininfo.pruned` is `Some(0)`.
+    let pruned_res = env_pruned.client.get_prune_height().unwrap();
+    assert_eq!(pruned_res, Some(0));
+
+    // Prune the last 2 blocks.
+    let _ = env_pruned.corepc_client.prune_blockchain(block_count - 2);
+
+    // Assert that `getblockchaininfo.pruned` is > 0.
+    // We can't assert on a specific block height because Bitcoin Core prunes
+    // at the block file level (`blkXXXX.dat`), and not at block height level.
+    let pruned_res = env_pruned.client.get_prune_height().unwrap();
+    assert!(pruned_res.unwrap() > 0);
+}