Allow passing metadata to a melt (#1148)

crates/cdk-integration-tests/tests/happy_path_mint_wallet.rs

@@ -9,6 +9,7 @@
 //! whether to use real Lightning Network payments (regtest mode) or simulated payments.
 
 use core::panic;
+use std::collections::HashMap;
 use std::env;
 use std::fmt::Debug;
 use std::path::PathBuf;
@@ -161,9 +162,23 @@ async fn test_happy_mint_melt_round_trip() {
 
     assert_eq!(response_json, expected_json);
 
-    let melt_response = wallet.melt(&melt.id).await.unwrap();
+    let mut metadata = HashMap::new();
+    metadata.insert("test".to_string(), "value".to_string());
+
+    let melt_response = wallet
+        .melt_with_metadata(&melt.id, metadata.clone())
+        .await
+        .unwrap();
     assert!(melt_response.preimage.is_some());
-    assert!(melt_response.state == MeltQuoteState::Paid);
+    assert_eq!(melt_response.state, MeltQuoteState::Paid);
+
+    let txs = wallet.list_transactions(None).await.unwrap();
+    let tx = txs
+        .into_iter()
+        .find(|tx| tx.quote_id == Some(melt.id.clone()))
+        .unwrap();
+    assert_eq!(tx.amount, melt.amount);
+    assert_eq!(tx.metadata, metadata);
 
     let (sub_id, payload) = get_notification(&mut reader, Duration::from_millis(15000)).await;
     // first message is the current state

crates/cdk/src/wallet/melt/melt_bolt11.rs

@@ -129,6 +129,18 @@ impl Wallet {
     /// Melt specific proofs
     #[instrument(skip(self, proofs))]
     pub async fn melt_proofs(&self, quote_id: &str, proofs: Proofs) -> Result<Melted, Error> {
+        self.melt_proofs_with_metadata(quote_id, proofs, HashMap::new())
+            .await
+    }
+
+    /// Melt specific proofs
+    #[instrument(skip(self, proofs))]
+    pub async fn melt_proofs_with_metadata(
+        &self,
+        quote_id: &str,
+        proofs: Proofs,
+        metadata: HashMap<String, String>,
+    ) -> Result<Melted, Error> {
         let quote_info = self
             .localstore
             .get_melt_quote(quote_id)
@@ -284,7 +296,7 @@ impl Wallet {
                 ys: proofs.ys()?,
                 timestamp: unix_time(),
                 memo: None,
-                metadata: HashMap::new(),
+                metadata,
                 quote_id: Some(quote_id.to_string()),
             })
             .await?;
@@ -320,6 +332,44 @@ impl Wallet {
     /// }
     #[instrument(skip(self))]
     pub async fn melt(&self, quote_id: &str) -> Result<Melted, Error> {
+        self.melt_with_metadata(quote_id, HashMap::new()).await
+    }
+
+    /// Melt with additional metadata to be saved locally with the transaction
+    /// # Synopsis
+    /// ```rust, no_run
+    ///  use std::sync::Arc;
+    ///
+    ///  use cdk_sqlite::wallet::memory;
+    ///  use cdk::nuts::CurrencyUnit;
+    ///  use cdk::wallet::Wallet;
+    ///  use rand::random;
+    ///
+    /// #[tokio::main]
+    /// async fn main() -> anyhow::Result<()> {
+    ///  let seed = random::<[u8; 64]>();
+    ///  let mint_url = "https://fake.thesimplekid.dev";
+    ///  let unit = CurrencyUnit::Sat;
+    ///
+    ///  let localstore = memory::empty().await?;
+    ///  let wallet = Wallet::new(mint_url, unit, Arc::new(localstore), seed, None).unwrap();
+    ///  let bolt11 = "lnbc100n1pnvpufspp5djn8hrq49r8cghwye9kqw752qjncwyfnrprhprpqk43mwcy4yfsqdq5g9kxy7fqd9h8vmmfvdjscqzzsxqyz5vqsp5uhpjt36rj75pl7jq2sshaukzfkt7uulj456s4mh7uy7l6vx7lvxs9qxpqysgqedwz08acmqwtk8g4vkwm2w78suwt2qyzz6jkkwcgrjm3r3hs6fskyhvud4fan3keru7emjm8ygqpcrwtlmhfjfmer3afs5hhwamgr4cqtactdq".to_string();
+    ///  let quote = wallet.melt_quote(bolt11, None).await?;
+    ///  let quote_id = quote.id;
+    ///
+    ///  let mut metadata = std::collections::HashMap::new();
+    ///  metadata.insert("my key".to_string(), "my value".to_string());
+    ///
+    ///  let _ = wallet.melt_with_metadata(&quote_id, metadata).await?;
+    ///
+    ///  Ok(())
+    /// }
+    #[instrument(skip(self))]
+    pub async fn melt_with_metadata(
+        &self,
+        quote_id: &str,
+        metadata: HashMap<String, String>,
+    ) -> Result<Melted, Error> {
         let quote_info = self
             .localstore
             .get_melt_quote(quote_id)
@@ -368,6 +418,7 @@ impl Wallet {
             input_proofs.extend_from_slice(&new_proofs);
         }
 
-        self.melt_proofs(quote_id, input_proofs).await
+        self.melt_proofs_with_metadata(quote_id, input_proofs, metadata)
+            .await
     }
 }