Add unit test coverage for get_nullifier_from_note

src/transaction.rs

@@ -23,6 +23,7 @@ use pivx_primitives::transaction::components::{OutPoint, TxOut};
 pub use pivx_primitives::transaction::fees::fixed::FeeRule;
 pub use pivx_primitives::transaction::Transaction;
 pub use pivx_primitives::zip32::AccountId;
+use pivx_primitives::zip32::ExtendedFullViewingKey;
 pub use pivx_primitives::zip32::ExtendedSpendingKey;
 pub use pivx_primitives::zip32::Scope;
 pub use pivx_proofs::prover::LocalTxProver;
@@ -276,17 +277,26 @@ pub fn get_nullifier_from_note(
 ) -> Result<JsValue, JsValue> {
     let extfvk =
         decode_extended_full_viewing_key(&enc_extfvk, is_testnet).map_err(|e| e.to_string())?;
+    let (note, hex_witness): (Note, String) = serde_wasm_bindgen::from_value(note_data)?;
+    let ser_nullifiers =
+        get_nullifier_from_note_internal(extfvk, note, hex_witness).map_err(|e| e.to_string())?;
+    Ok(serde_wasm_bindgen::to_value(&ser_nullifiers)?)
+}
+
+pub fn get_nullifier_from_note_internal(
+    extfvk: ExtendedFullViewingKey,
+    note: Note,
+    hex_witness: String,
+) -> Result<String, Box<dyn Error>> {
     let nullif_key = extfvk
         .to_diversifiable_full_viewing_key()
         .to_nk(Scope::External);
-    let (note, hex_witness): (Note, String) = serde_wasm_bindgen::from_value(note_data)?;
     let witness = Cursor::new(hex::decode(hex_witness).map_err(|e| e.to_string())?);
     let path = IncrementalWitness::<Node>::read(witness)
         .map_err(|_| "Cannot read witness from buffer")?
         .path()
         .ok_or("Cannot find witness path")?;
-    let ser_nullifiers = hex::encode(note.nf(&nullif_key, path.position).0);
-    Ok(serde_wasm_bindgen::to_value(&ser_nullifiers)?)
+    Ok(hex::encode(note.nf(&nullif_key, path.position).0))
 }
 
 #[derive(Serialize, Deserialize)]

src/transaction/test.rs

@@ -1,6 +1,6 @@
 #![cfg(test)]
 
-use crate::transaction::create_transaction_internal;
+use crate::transaction::{create_transaction_internal, get_nullifier_from_note_internal};
 
 use super::handle_transaction_internal;
 use either::Either;
@@ -15,6 +15,7 @@ use pivx_primitives::sapling::value::NoteValue;
 use pivx_primitives::sapling::Node;
 use pivx_primitives::sapling::Note;
 use pivx_primitives::sapling::Rseed::BeforeZip212;
+use pivx_primitives::zip32::Scope;
 use std::error::Error;
 use std::io::Cursor;
 
@@ -92,7 +93,7 @@ pub async fn test_create_transaction() -> Result<(), Box<dyn Error>> {
     path.write(&mut path_vec)?;
     let path = hex::encode(path_vec);
     let tx = create_transaction_internal(
-        Either::Left(vec![(note.clone(), path)]),
+        Either::Left(vec![(note.clone(), path.clone())]),
         &extended_spending_key,
         output,
         address,
@@ -108,7 +109,15 @@ pub async fn test_create_transaction() -> Result<(), Box<dyn Error>> {
         nullifier,
         "5269442d8022af933774f9f22775566d92089a151ba733f6d751f5bb65a7f56d"
     );
-    // When we implement mempool, test that new notes work correctly
+    // Verify that get_nullifier_from_note_internal yields the same nullifier
+    assert_eq!(
+        get_nullifier_from_note_internal(
+            extended_spending_key.to_extended_full_viewing_key(),
+            note.clone(),
+            path
+        )?,
+        "5269442d8022af933774f9f22775566d92089a151ba733f6d751f5bb65a7f56d"
+    );
 
     Ok(())
 }