refactor: update note_getter to NOT fail if returning 0 notes

noir-projects/aztec-nr/aztec/src/note/note_getter/mod.nr

@@ -161,8 +161,6 @@ fn constrain_get_notes_internal<Note, N, M, FILTER_ARGS>(
         assert(filtered_notes[i].is_none(), "Got more notes than limit.");
     }
 
-    assert(returned_notes.len() != 0, "Cannot return zero notes");
-
     returned_notes
 }
 

noir-projects/aztec-nr/aztec/src/note/note_getter/test.nr

@@ -92,17 +92,6 @@ fn collapses_notes_at_the_beginning_of_the_array() {
     assert_equivalent_vec_and_array(returned, expected);
 }
 
-#[test(should_fail_with="Cannot return zero notes")]
-fn rejects_zero_notes() {
-    let mut env = setup();
-    let mut context = env.private();
-
-    let opt_notes: [Option<MockNote>; MAX_NOTE_HASH_READ_REQUESTS_PER_CALL] = [Option::none(); MAX_NOTE_HASH_READ_REQUESTS_PER_CALL];
-
-    let options = NoteGetterOptions::new();
-    let _ = constrain_get_notes_internal(&mut context, storage_slot, opt_notes, options);
-}
-
 #[test(should_fail_with="Got more notes than limit.")]
 fn rejects_mote_notes_than_limit() {
     let mut env = setup();

noir-projects/noir-contracts/contracts/benchmarking_contract/src/main.nr

@@ -31,7 +31,7 @@ contract Benchmarking {
         let owner_notes = storage.notes.at(owner);
         let mut getter_options = NoteGetterOptions::new();
         let notes = owner_notes.get_notes(getter_options.set_limit(1).set_offset(index));
-        let note = notes.get_unchecked(0);
+        let note = notes.get(0);
         owner_notes.remove(note);
         increment(owner_notes, note.value, owner, outgoing_viewer);
     }

noir-projects/noir-contracts/contracts/child_contract/src/main.nr

@@ -65,7 +65,7 @@ contract Child {
         let mut options = NoteGetterOptions::new();
         options = options.select(ValueNote::properties().value, amount, Option::none()).set_limit(1);
         let notes = storage.a_map_with_private_values.at(owner).get_notes(options);
-        notes.get_unchecked(0).value
+        notes.get(0).value
     }
 
     // Increments `current_value` by `new_value`

noir-projects/noir-contracts/contracts/delegated_on_contract/src/main.nr

@@ -35,7 +35,7 @@ contract DelegatedOn {
         let mut options = NoteGetterOptions::new();
         options = options.select(ValueNote::properties().value, amount, Option::none()).set_limit(1);
         let notes = storage.a_map_with_private_values.at(owner).get_notes(options);
-        notes.get_unchecked(0).value
+        notes.get(0).value
     }
 
     unconstrained fn view_public_value() -> pub Field {

noir-projects/noir-contracts/contracts/delegator_contract/src/main.nr

@@ -35,7 +35,7 @@ contract Delegator {
         let mut options = NoteGetterOptions::new();
         options = options.select(ValueNote::properties().value, amount, Option::none()).set_limit(1);
         let notes = storage.a_map_with_private_values.at(owner).get_notes(options);
-        notes.get_unchecked(0).value
+        notes.get(0).value
     }
 
     unconstrained fn view_public_value() -> pub Field {

noir-projects/noir-contracts/contracts/inclusion_proofs_contract/src/main.nr

@@ -55,7 +55,7 @@ contract InclusionProofs {
         if (nullified) {
             options = options.set_status(NoteStatus.ACTIVE_OR_NULLIFIED);
         }
-        let note = private_values.get_notes(options).get_unchecked(0);
+        let note = private_values.get_notes(options).get(0);
         // docs:end:get_note_from_pxe
 
         // 2) Prove the note inclusion
@@ -106,7 +106,7 @@ contract InclusionProofs {
         if (fail_case) {
             options = options.set_status(NoteStatus.ACTIVE_OR_NULLIFIED);
         }
-        let note = private_values.get_notes(options).get_unchecked(0);
+        let note = private_values.get_notes(options).get(0);
 
         let header = if (use_block_number) {
             context.get_header_at(block_number)

noir-projects/noir-contracts/contracts/pending_note_hashes_contract/src/main.nr

@@ -59,19 +59,14 @@ contract PendingNoteHashes {
         let options = NoteGetterOptions::with_filter(filter_notes_min_sum, amount);
         // get note (note inserted at bottom of function shouldn't exist yet)
         let notes = owner_balance.get_notes(options);
-
-        // TODO https://github.com/AztecProtocol/aztec-packages/issues/7059: clean this test up - we won't actually hit 
-        // this assert because the same one exists in get_notes (we always return at least one note), so all lines after 
-        // this one are effectively dead code. We should find a different way to test what this function attempts to 
-        // test.
         assert(notes.len() == 0);
 
         let header = context.get_header();
         let owner_npk_m_hash = header.get_npk_m_hash(&mut context, owner);
 
         // Insert note
         let mut note = ValueNote::new(amount, owner_npk_m_hash);
-        owner_balance.insert(&mut note).emit(encode_and_encrypt_note(&mut context, context.msg_sender(), owner));
+        owner_balance.insert(&mut note).discard();
 
         0
     }

noir-projects/noir-contracts/contracts/static_child_contract/src/main.nr

@@ -73,7 +73,7 @@ contract StaticChild {
             Option::none()
         ).set_limit(1);
         let notes = storage.a_private_value.get_notes(options);
-        notes.get_unchecked(0).value
+        notes.get(0).value
     }
 
     // Increments `current_value` by `new_value`

noir-projects/noir-contracts/contracts/test_contract/src/main.nr

@@ -472,7 +472,7 @@ contract Test {
         let mut options = NoteGetterOptions::new();
         options = options.select(TestNote::properties().value, secret_hash, Option::none()).set_limit(1);
         let notes = notes_set.get_notes(options);
-        let note = notes.get_unchecked(0);
+        let note = notes.get(0);
         notes_set.remove(note);
     }
 

noir-projects/noir-contracts/contracts/token_blacklist_contract/src/main.nr

@@ -173,7 +173,7 @@ contract TokenBlacklist {
             Option::none()
         ).set_limit(1);
         let notes = pending_shields.get_notes(options);
-        let note = notes.get_unchecked(0);
+        let note = notes.get(0);
         // Remove the note from the pending shields set
         pending_shields.remove(note);
 

noir-projects/noir-contracts/contracts/token_contract/src/main.nr

@@ -295,7 +295,8 @@ contract Token {
             Option::none()
         ).set_limit(1);
         let notes = pending_shields.get_notes(options);
-        let note = notes.get_unchecked(0);
+        assert(notes.len() == 1, "No pending shield found");
+        let note = notes.get(0);
         // Remove the note from the pending shields set
         pending_shields.remove(note);
 
@@ -354,7 +355,6 @@ contract Token {
      * Accumulate value by spending notes until we hit the missing amount
      * If not enough notes are available, recurse to do it again.
      * Will use MORE notes than the transfer directly since there are much smaller usual overhead on this function.
-     * Will fail with `Cannot return zero notes` if there are not enough notes to cover the amount.
      */
     #[aztec(private)]
     #[aztec(internal)]

noir-projects/noir-contracts/contracts/token_contract/src/test/minting.nr

@@ -88,7 +88,7 @@ unconstrained fn mint_private_success() {
     utils::check_private_balance(token_contract_address, owner, mint_amount);
 }
 
-#[test(should_fail_with="Cannot return zero notes")]
+#[test(should_fail_with="No pending shield found")]
 unconstrained fn mint_private_failure_double_spend() {
     // Setup without account contracts. We are not using authwits here, so dummy accounts are enough
     let (env, token_contract_address, owner, recipient) = utils::setup(/* with_account_contracts */ false);

noir-projects/noir-contracts/contracts/token_contract/src/types/balances_map.nr

@@ -123,7 +123,7 @@ impl<T> BalancesMap<T, &mut PrivateContext> {
         let options = NoteGetterOptions::with_filter(filter_notes_min_sum, subtrahend).set_limit(limit);
         let notes = self.map.at(owner).get_notes(options);
 
-        assert(notes.len() > 0, "No notes found");
+        assert(notes.len() > 0, "Balance too low");
 
         let mut minuend: U128 = U128::from_integer(0);
         for i in 0..options.limit {

yarn-project/end-to-end/src/e2e_blacklist_token_contract/minting.test.ts

@@ -111,7 +111,7 @@ describe('e2e_blacklist_token_contract mint', () => {
           'The note has been destroyed.',
         );
         await expect(asset.methods.redeem_shield(wallets[0].getAddress(), amount, secret).prove()).rejects.toThrow(
-          `Assertion failed: Cannot return zero notes`,
+          "Cannot satisfy constraint 'index < self.len'",
         );
       });
 

yarn-project/end-to-end/src/e2e_card_game.test.ts

@@ -183,7 +183,7 @@ describe('e2e_card_game', () => {
           .join_game(GAME_ID, [cardToField(firstPlayerCollection[0]), cardToField(firstPlayerCollection[1])])
           .send()
           .wait(),
-      ).rejects.toThrow(`Assertion failed: Cannot return zero notes`);
+      ).rejects.toThrow("Cannot satisfy constraint 'index < self.len'");
 
       const collection = await contract.methods.view_collection_cards(firstPlayer, 0).simulate({ from: firstPlayer });
       expect(boundedVecToArray(collection)).toHaveLength(1);

yarn-project/end-to-end/src/e2e_note_getter.test.ts

@@ -182,7 +182,7 @@ describe('e2e_note_getter', () => {
         'index < self.len', // from BoundedVec::get
       );
       await expect(contract.methods.call_get_notes(storageSlot, activeOrNullified).prove()).rejects.toThrow(
-        `Assertion failed: Cannot return zero notes`,
+        "Cannot satisfy constraint 'index < self.len'",
       );
     }
 

yarn-project/end-to-end/src/e2e_pending_note_hashes_contract.test.ts

@@ -109,7 +109,7 @@ describe('e2e_pending_note_hashes_contract', () => {
       .send()
       .wait();
     await expect(deployedContract.methods.get_note_zero_balance(owner).prove()).rejects.toThrow(
-      `Assertion failed: Cannot return zero notes`,
+      "Cannot satisfy constraint 'index < self.len'",
     );
 
     await expectNoteHashesSquashedExcept(0);
@@ -245,7 +245,7 @@ describe('e2e_pending_note_hashes_contract', () => {
       .send()
       .wait();
     await expect(deployedContract.methods.get_note_zero_balance(owner).prove()).rejects.toThrow(
-      `Assertion failed: Cannot return zero notes`,
+      "Cannot satisfy constraint 'index < self.len'",
     );
 
     // second TX creates 1 note, but it is squashed!

yarn-project/end-to-end/src/e2e_token_contract/minting.test.ts

@@ -101,7 +101,7 @@ describe('e2e_token_contract minting', () => {
           'The note has been destroyed.',
         );
         await expect(asset.methods.redeem_shield(accounts[0].address, amount, secret).simulate()).rejects.toThrow(
-          `Assertion failed: Cannot return zero notes`,
+          "Cannot satisfy constraint 'index < self.len'",
         );
       });
 

yarn-project/end-to-end/src/e2e_token_contract/odd_transfer_private.test.ts

@@ -72,7 +72,7 @@ describe('e2e_token_contract transfer private', () => {
       const amount = balance0 + 1n;
       expect(amount).toBeGreaterThan(0n);
       await expect(asset.methods.transfer(accounts[1].address, amount).simulate()).rejects.toThrow(
-        "Assertion failed: Cannot return zero notes 'returned_notes.len() != 0'",
+        'Assertion failed: Balance too low',
       );
     });
   });

yarn-project/end-to-end/src/e2e_token_contract/transfer_private.test.ts

@@ -108,7 +108,7 @@ describe('e2e_token_contract transfer private', () => {
       const amount = balance0 + 1n;
       expect(amount).toBeGreaterThan(0n);
       await expect(asset.methods.transfer(accounts[1].address, amount).simulate()).rejects.toThrow(
-        "Assertion failed: Cannot return zero notes 'returned_notes.len() != 0'",
+        'Assertion failed: Balance too low',
       );
     });
 

yarn-project/end-to-end/src/guides/dapp_testing.test.ts

@@ -215,18 +215,14 @@ describe('guides/dapp/testing', () => {
       it('asserts a local transaction simulation fails by calling simulate', async () => {
         // docs:start:local-tx-fails
         const call = token.methods.transfer(recipient.getAddress(), 200n);
-        await expect(call.prove()).rejects.toThrow(
-          "Assertion failed: Cannot return zero notes 'returned_notes.len() != 0'",
-        );
+        await expect(call.prove()).rejects.toThrow('Assertion failed: Balance too low');
         // docs:end:local-tx-fails
       });
 
       it('asserts a local transaction simulation fails by calling send', async () => {
         // docs:start:local-tx-fails-send
         const call = token.methods.transfer(recipient.getAddress(), 200n);
-        await expect(call.send().wait()).rejects.toThrow(
-          "Assertion failed: Cannot return zero notes 'returned_notes.len() != 0'",
-        );
+        await expect(call.send().wait()).rejects.toThrow('Assertion failed: Balance too low');
         // docs:end:local-tx-fails-send
       });
 

yarn-project/simulator/src/client/private_execution.test.ts

@@ -1109,13 +1109,13 @@ describe('Private Execution test suite', () => {
       const artifact = getFunctionArtifact(PendingNoteHashesContractArtifact, 'test_bad_get_then_insert_flat');
 
       const args = [amountToTransfer, owner];
-      await expect(() =>
-        runSimulator({
-          args: args,
-          artifact: artifact,
-          contractAddress,
-        }),
-      ).rejects.toThrow(`Assertion failed: Cannot return zero notes`);
+
+      // This will throw if we can read the note before it was inserted.
+      await runSimulator({
+        args: args,
+        artifact: artifact,
+        contractAddress,
+      });
     });
   });
 
@@ -1143,7 +1143,7 @@ describe('Private Execution test suite', () => {
       oracle.getNotes.mockResolvedValue([]);
 
       await expect(() => runSimulator({ artifact, args })).rejects.toThrow(
-        `Assertion failed: Cannot return zero notes`,
+        "Cannot satisfy constraint 'index < self.len'",
       );
     });
   });