test(tx_graph): Add test list_canonical_transactions

crates/chain/tests/test_tx_graph.rs

@@ -1091,6 +1091,45 @@ fn update_last_seen_unconfirmed() {
     );
 }
 
+#[test]
+fn list_canonical_transactions() {
+    // Transactions inserted into a TxGraph won't be considered canonical
+    // until given an anchor (in best chain) or a last_seen time.
+    let txs = vec![new_tx(0), new_tx(1)];
+    let txids: Vec<Txid> = txs.iter().map(Transaction::txid).collect();
+
+    // graph
+    let mut graph = TxGraph::<BlockId>::new(txs);
+    let full_txs: Vec<_> = graph.full_txs().collect();
+    assert_eq!(full_txs.len(), 2);
+
+    // chain
+    let blocks: BTreeMap<u32, BlockHash> = [(0, h!("g")), (1, h!("A")), (2, h!("B"))]
+        .into_iter()
+        .collect();
+    let chain = LocalChain::from_blocks(blocks).unwrap();
+    let canonical_txs: Vec<_> = graph
+        .list_canonical_transactions(&chain, chain.tip().block_id())
+        .collect();
+    assert!(canonical_txs.is_empty());
+
+    // tx0 with seen_at should be returned by canonical txs
+    let _ = graph.insert_seen_at(txids[0], 2);
+    let mut canonical_txs = graph.list_canonical_transactions(&chain, chain.tip().block_id());
+    assert_eq!(
+        canonical_txs.next().map(|tx| tx.tx_node.txid).unwrap(),
+        txids[0]
+    );
+    drop(canonical_txs);
+
+    // tx1 with anchor is also canonical
+    let _ = graph.insert_anchor(txids[1], block_id!(2, "B"));
+    let mut canonical_txs = graph.list_canonical_transactions(&chain, chain.tip().block_id());
+    assert!(canonical_txs
+        .find(|tx| tx.tx_node.txid == txids[1])
+        .is_some());
+}
+
 #[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.