commands: add a 'spend_info' field to the 'listcoins' entries

doc/API.md

@@ -81,11 +81,20 @@ This command does not take any parameter for now.
 
 #### Response
 
-| Field          | Type          | Description                                                      |
-| -------------- | ------------- | ---------------------------------------------------------------- |
-| `amount`       | int           | Value of the TxO in satoshis                                     |
-| `outpoint`     | string        | Transaction id and output index of this coin                     |
-| `block_height` | int or null   | Blockheight the transaction was confirmed at, or `null`          |
+| Field          | Type          | Description                                                                                                        |
+| -------------- | ------------- | ------------------------------------------------------------------------------------------------------------------ |
+| `amount`       | int           | Value of the TxO in satoshis.                                                                                      |
+| `outpoint`     | string        | Transaction id and output index of this coin.                                                                      |
+| `block_height` | int or null   | Blockheight the transaction was confirmed at, or `null`.                                                           |
+| `spend_info`   | object        | Information about the transaction spending this coin. See [Spending transaction info](#spending_transaction_info). |
+
+
+##### Spending transaction info
+
+| Field      | Type        | Description                                                    |
+| ---------- | ----------- | -------------------------------------------------------------- |
+| `txid`     | str         | Spending transaction's id.                                     |
+| `height`   | int or null | Block height the spending tx was included at, if confirmed.    |
 
 
 ### `createspend`

src/commands/mod.rs

@@ -169,10 +169,7 @@ impl DaemonControl {
     pub fn get_info(&self) -> GetInfoResult {
         let mut db_conn = self.db.connection();
 
-        let blockheight = db_conn
-            .chain_tip()
-            .map(|tip| tip.height)
-            .unwrap_or(0);
+        let blockheight = db_conn.chain_tip().map(|tip| tip.height).unwrap_or(0);
         GetInfoResult {
             version: VERSION.to_string(),
             network: self.config.bitcoin_config.network,
@@ -211,12 +208,19 @@ impl DaemonControl {
                     amount,
                     outpoint,
                     block_height,
+                    spend_txid,
+                    spend_block,
                     ..
                 } = coin;
+                let spend_info = spend_txid.map(|txid| LCSpendInfo {
+                    txid,
+                    height: spend_block.map(|b| b.height),
+                });
                 ListCoinsEntry {
                     amount,
                     outpoint,
                     block_height,
+                    spend_info,
                 }
             })
             .collect();
@@ -464,7 +468,14 @@ pub struct GetAddressResult {
     pub address: bitcoin::Address,
 }
 
-#[derive(Debug, Clone, Serialize, Deserialize)]
+#[derive(Debug, Clone, Copy, Serialize, Deserialize)]
+pub struct LCSpendInfo {
+    pub txid: bitcoin::Txid,
+    /// The block height this spending transaction was confirmed at.
+    pub height: Option<i32>,
+}
+
+#[derive(Debug, Clone, Copy, Serialize, Deserialize)]
 pub struct ListCoinsEntry {
     #[serde(
         serialize_with = "ser_amount",
@@ -473,6 +484,8 @@ pub struct ListCoinsEntry {
     pub amount: bitcoin::Amount,
     pub outpoint: bitcoin::OutPoint,
     pub block_height: Option<i32>,
+    /// Information about the transaction spending this coin.
+    pub spend_info: Option<LCSpendInfo>,
 }
 
 #[derive(Debug, Clone, Serialize, Deserialize)]

tests/test_framework/utils.py

@@ -8,6 +8,9 @@ import subprocess
 import threading
 import time
 
+from io import BytesIO
+from .serializations import CTransaction, PSBT
+
 TIMEOUT = int(os.getenv("TIMEOUT", 20))
 EXECUTOR_WORKERS = int(os.getenv("EXECUTOR_WORKERS", 20))
 VERBOSE = os.getenv("VERBOSE", "0") == "1"
@@ -43,6 +46,35 @@ def wait_for(success, timeout=TIMEOUT, debug_fn=None):
         raise ValueError("Error waiting for {}", success)
 
 
+def get_txid(hex_tx):
+    """Get the txid (as hex) of the given (as hex) transaction."""
+    tx = CTransaction()
+    tx.deserialize(BytesIO(bytes.fromhex(hex_tx)))
+    return tx.txid().hex()
+
+
+def spend_coins(minisafed, bitcoind, coins):
+    """Spend these coins, no matter how.
+    This will create a single transaction spending them all at once at the minimum
+    feerate. This will broadcast but not confirm the transaction.
+
+    :param coins: a list of dict as returned by listcoins. The coins must all exist.
+    :returns: the broadcasted transaction, as hex.
+    """
+    total_value = sum(c["amount"] for c in coins)
+    destinations = {
+        bitcoind.rpc.getnewaddress(): total_value - 11 - 31 - 300 * len(coins)
+    }
+    res = minisafed.rpc.createspend([c["outpoint"] for c in coins], destinations, 1)
+
+    psbt = PSBT()
+    psbt.deserialize(res["psbt"])
+    tx = minisafed.sign_psbt(psbt)
+    bitcoind.rpc.sendrawtransaction(tx)
+
+    return tx
+
+
 class RpcError(ValueError):
     def __init__(self, method: str, params: dict, error: str):
         super(ValueError, self).__init__(

tests/test_rpc.py

@@ -1,6 +1,6 @@
 from fixtures import *
 from test_framework.serializations import PSBT
-from test_framework.utils import wait_for, COIN
+from test_framework.utils import wait_for, COIN, get_txid, spend_coins
 
 
 def test_getinfo(minisafed):
@@ -34,6 +34,7 @@ def test_listcoins(minisafed, bitcoind):
     assert txid == res[0]["outpoint"][:64]
     assert res[0]["amount"] == 1 * COIN
     assert res[0]["block_height"] is None
+    assert res[0]["spend_info"] is None
 
     # If the coin gets confirmed, it'll be marked as such.
     bitcoind.generate_block(1, wait_for_mempool=txid)
@@ -42,6 +43,22 @@ def test_listcoins(minisafed, bitcoind):
         lambda: minisafed.rpc.listcoins()["coins"][0]["block_height"] == block_height
     )
 
+    # Same if the coin gets spent.
+    spend_tx = spend_coins(minisafed, bitcoind, (res[0],))
+    spend_txid = get_txid(spend_tx)
+    wait_for(lambda: minisafed.rpc.listcoins()["coins"][0]["spend_info"] is not None)
+    spend_info = minisafed.rpc.listcoins()["coins"][0]["spend_info"]
+    assert spend_info["txid"] == spend_txid
+    assert spend_info["height"] is None
+
+    # And if this spending tx gets confirmed.
+    bitcoind.generate_block(1, wait_for_mempool=spend_txid)
+    curr_height = bitcoind.rpc.getblockcount()
+    wait_for(lambda: minisafed.rpc.getinfo()["blockheight"] == curr_height)
+    spend_info = minisafed.rpc.listcoins()["coins"][0]["spend_info"]
+    assert spend_info["txid"] == spend_txid
+    assert spend_info["height"] == curr_height
+
 
 def test_jsonrpc_server(minisafed, bitcoind):
     """Test passing parameters as a list or a mapping."""