test(tx_graph): Add test list_canonical_txs

crates/chain/tests/test_tx_graph.rs

@@ -1098,6 +1098,52 @@ fn update_last_seen_unconfirmed() {
     );
 }
 
+#[test]
+fn list_canonical_txs() {
+    use bdk_chain::local_chain::CheckPoint;
+    let mut graph = TxGraph::<BlockId>::default();
+
+    // insert three new txs
+    // all graph transactions are present, but not canonical
+    let txs = vec![new_tx(0), new_tx(1), new_tx(2)];
+    let txids: Vec<_> = txs.iter().map(Transaction::txid).collect();
+    for tx in txs {
+        let _ = graph.insert_tx(tx);
+    }
+    let full_txs: Vec<_> = graph.full_txs().collect();
+    assert_eq!(full_txs.len(), 3);
+
+    let cp = CheckPoint::from_block_ids(
+        [(0, BlockHash::all_zeros()), (2, BlockHash::all_zeros())]
+            .into_iter()
+            .map(BlockId::from),
+    )
+    .unwrap();
+    let anchor: BlockId = cp.iter().next().unwrap().block_id();
+    let chain = LocalChain::from_tip(cp).unwrap();
+
+    let canonical_txs: Vec<_> = graph
+        .canonical_transactions(&chain, chain.tip().block_id())
+        .collect();
+    assert!(canonical_txs.is_empty());
+
+    // insert seen_at for tx0, it should be returned by `canonical_transactions`
+    let _ = graph.insert_seen_at(txids[0], 0);
+    let canonical_txs: Vec<_> = graph
+        .canonical_transactions(&chain, chain.tip().block_id())
+        .collect();
+    assert_eq!(canonical_txs.len(), 1);
+    assert_eq!(canonical_txs.first().unwrap().tx_node.txid, txids[0]);
+
+    // insert anchor for tx1, it is now also canonical
+    let _ = graph.insert_anchor(txids[1], anchor);
+    let canonical_txs: BTreeSet<_> = graph
+        .canonical_transactions(&chain, chain.tip().block_id())
+        .collect();
+    assert_eq!(canonical_txs.len(), 2);
+    assert_eq!(canonical_txs.first().unwrap().tx_node.txid, txids[1]);
+}
+
 #[test]
 /// The `map_anchors` allow a caller to pass a function to reconstruct the [`TxGraph`] with any [`Anchor`],
 /// even though the function is non-deterministic.