docs: [WIP] Initial work on intent tracker example

Author: evanlinjin

wallet/Cargo.toml

@@ -44,6 +44,8 @@ bdk_chain = { version = "0.23.0", features = ["rusqlite"] }
 bdk_wallet = { path = ".", features = ["rusqlite", "file_store", "test-utils"] }
 anyhow = "1"
 rand = "^0.8"
+bdk_testenv = "0.13"
+bdk_bitcoind_rpc = { version = "0.20"  }
 
 [package.metadata.docs.rs]
 all-features = true
@@ -58,3 +60,7 @@ required-features = ["all-keys"]
 name = "miniscriptc"
 path = "examples/compiler.rs"
 required-features = ["compiler"]
+
+[[example]]
+name = "intent_tracker"
+path = "examples/intent_tracker.rs"

wallet/examples/intent_tracker.rs

@@ -0,0 +1,84 @@
+use std::{str::FromStr, sync::Arc, time::Duration};
+
+use anyhow::Context;
+use bdk_testenv::{bitcoincore_rpc::RpcApi, TestEnv};
+use bdk_wallet::{KeychainKind, SignOptions, Wallet};
+use bitcoin::{Amount, Network, Txid};
+
+const DESCRIPTOR: &str = bdk_testenv::utils::DESCRIPTORS[3];
+
+fn main() -> anyhow::Result<()> {
+    let env = TestEnv::new().context("failed to start testenv")?;
+    env.mine_blocks(101, None)
+        .context("failed to mine blocks")?;
+
+    let mut wallet = Wallet::create_single(DESCRIPTOR)
+        .network(Network::Regtest)
+        .create_wallet_no_persist()
+        .context("failed to construct wallet")?;
+
+    let mut emitter = bdk_bitcoind_rpc::Emitter::new(
+        env.rpc_client(),
+        wallet.latest_checkpoint(),
+        0,
+        wallet
+            .transactions()
+            .filter(|tx| tx.chain_position.is_unconfirmed())
+            .map(|tx| tx.tx_node.txid),
+    );
+    while let Some(block_event) = emitter.next_block()? {
+        wallet.apply_block(&block_event.block, block_event.block_height())?;
+    }
+
+    // Receive an unconfirmed tx, spend from it, and the unconfirmed tx get's RBF'ed.
+    // Our API should be able to recognise that the outgoing tx became evicted and allow the caller
+    // to respond accordingly.
+    let wallet_addr = wallet.next_unused_address(KeychainKind::External).address;
+    let remote_addr = env
+        .rpc_client()
+        .get_new_address(None, None)?
+        .assume_checked();
+    let incoming_txid = env.send(&wallet_addr, Amount::ONE_BTC)?;
+
+    let mempool_event = emitter.mempool()?;
+    wallet.apply_evicted_txs(mempool_event.evicted_ats());
+    wallet.apply_unconfirmed_txs(mempool_event.new_txs);
+    assert_eq!(wallet.balance().total(), Amount::ONE_BTC);
+
+    // Create & broadcast outgoing tx.
+    let mut tx_builder = wallet.build_tx();
+    tx_builder.add_recipient(remote_addr, Amount::ONE_BTC / 2);
+    let mut psbt = tx_builder.finish()?;
+    assert!(wallet.sign(&mut psbt, SignOptions::default())?);
+    let outgoing_tx = psbt.extract_tx()?;
+    wallet.track_tx(outgoing_tx.clone());
+    assert_eq!(wallet.uncanonical_txs().count(), 1);
+
+    // Sync.
+    let outgoing_txid = env.rpc_client().send_raw_transaction(&outgoing_tx)?;
+    env.wait_until_electrum_sees_txid(outgoing_txid, Duration::from_secs(5))?;
+    let mempool_event = emitter.mempool()?;
+    // TODO: Why is `outgoing_txid` not emitted?
+    println!("mempool_event: {mempool_event:#?}");
+    wallet.apply_evicted_txs(mempool_event.evicted_ats());
+    wallet.apply_unconfirmed_txs(mempool_event.new_txs);
+    let tx = wallet
+        .canonical_txs()
+        .find(|tx| tx.tx_node.txid == outgoing_txid)
+        .expect("must find outgoing tx");
+    assert_eq!(wallet.uncanonical_txs().count(), 0);
+
+    // RBF incoming tx.
+    let res = env
+        .rpc_client()
+        .call::<serde_json::Value>("bumpfee", &[incoming_txid.to_string().into()])?;
+    let incoming_replacement_txid = Txid::from_str(res.get("txid").unwrap().as_str().unwrap())?;
+
+    let mempool_event = emitter.mempool()?;
+    wallet.apply_evicted_txs(mempool_event.evicted_ats());
+    wallet.apply_unconfirmed_txs(mempool_event.new_txs);
+
+    for uncanonical_tx in wallet.uncanonical_txs() {}
+
+    Ok(())
+}