feat: FieldNote (AztecProtocol#3037)

1. Fixes AztecProtocol#2948
2. Removed redundant dependency from `TokenContract`.
3. No camel case in `TestContract`

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

@@ -385,8 +385,10 @@ describe('Private Execution test suite', () => {
 
     beforeAll(async () => {
       // These args should match the ones hardcoded in importer contract
-      const dummyNote = { amount: 1, secretHash: 2 };
-      const deepStruct = { aField: 1, aBool: true, aNote: dummyNote, manyNotes: [dummyNote, dummyNote, dummyNote] };
+      // eslint-disable-next-line camelcase
+      const dummyNote = { amount: 1, secret_hash: 2 };
+      // eslint-disable-next-line camelcase
+      const deepStruct = { a_field: 1, a_bool: true, a_note: dummyNote, many_notes: [dummyNote, dummyNote, dummyNote] };
       args = [1, true, 1, [1, 2], dummyNote, deepStruct];
       testCodeGenArtifact = getFunctionArtifact(TestContractArtifact, 'test_code_gen');
       const serializedArgs = encodeArguments(testCodeGenArtifact, args);

yarn-project/aztec-nr/field-note/Nargo.toml

@@ -0,0 +1,8 @@
+[package]
+name = "field_note"
+authors = ["aztec-labs"]
+compiler_version = "0.7.1"
+type = "lib"
+
+[dependencies]
+aztec = { path = "../aztec" }

yarn-project/aztec-nr/field-note/src/field_note.nr

@@ -0,0 +1,90 @@
+use dep::aztec::{
+    note::{
+        note_header::NoteHeader,
+        note_interface::NoteInterface,
+    },
+    hash::pedersen_hash,
+    context::PrivateContext,
+};
+
+global FIELD_NOTE_LEN: Field = 1;
+
+// A note which stores a field and is expected to be passed around using the `addNote` function.
+// WARNING: This Note is not private as it does not contain randomness and hence it can be easy to perform preimage
+// attack on it.
+struct FieldNote {
+    value: Field,
+    header: NoteHeader,
+}
+
+impl FieldNote {
+    pub fn new(value: Field) -> Self {
+        FieldNote {
+            value,
+            header: NoteHeader::empty(),
+        }
+    }
+
+    pub fn serialize(self) -> [Field; FIELD_NOTE_LEN]{
+        [self.value]
+    }
+
+    pub fn deserialize(preimage: [Field; FIELD_NOTE_LEN]) -> Self {
+        FieldNote {
+            value: preimage[0],
+            header: NoteHeader::empty(),
+        }
+    }
+
+    pub fn compute_note_hash(self) -> Field {
+        // TODO(#1205) Should use a non-zero generator index.
+        pedersen_hash(self.serialize(), 0)
+    }
+
+    pub fn compute_nullifier(self) -> Field {
+        // This note is expected to be shared between users and for this reason can't be nullified using a secret.
+        0
+    }
+
+    pub fn set_header(&mut self, header: NoteHeader) {
+        self.header = header;
+    }
+}
+
+fn deserialize(preimage: [Field; FIELD_NOTE_LEN]) -> FieldNote {
+    FieldNote::deserialize(preimage)
+}
+
+fn serialize(note: FieldNote) -> [Field; FIELD_NOTE_LEN]{
+    note.serialize()
+}
+
+fn compute_note_hash(note: FieldNote) -> Field {
+    note.compute_note_hash()
+}
+
+fn compute_nullifier(note: FieldNote) -> Field {
+    note.compute_nullifier()
+}
+
+fn get_header(note: FieldNote) -> NoteHeader {
+    note.header
+}
+
+fn set_header(note: &mut FieldNote, header: NoteHeader) {
+    note.set_header(header);
+}
+
+fn broadcast(context: &mut PrivateContext, slot: Field, note: FieldNote) {
+    assert(false, "FieldNote does not support broadcast. Add it to PXE directly using the `.addNote` function.");
+}
+
+global FieldNoteMethods = NoteInterface {
+    deserialize,
+    serialize,
+    compute_note_hash,
+    compute_nullifier,
+    get_header,
+    set_header,
+    broadcast,
+};

yarn-project/aztec-nr/field-note/src/lib.nr

@@ -0,0 +1 @@
+mod field_note;

yarn-project/end-to-end/src/e2e_non_contract_account.test.ts

@@ -4,7 +4,7 @@ import { siloNullifier } from '@aztec/circuits.js/abis';
 import { DebugLogger } from '@aztec/foundation/log';
 import { toBigInt } from '@aztec/foundation/serialize';
 import { TestContract } from '@aztec/noir-contracts/types';
-import { AztecNode, PXE, TxStatus } from '@aztec/types';
+import { AztecNode, NotePreimage, PXE, TxStatus } from '@aztec/types';
 
 import { setup } from './fixtures/utils.js';
 
@@ -17,9 +17,9 @@ describe('e2e_non_contract_account', () => {
   let logger: DebugLogger;
 
   let contract: TestContract;
+  let wallet: Wallet;
 
   beforeEach(async () => {
-    let wallet: Wallet;
     ({ teardown, aztecNode, pxe, wallet, logger } = await setup(1));
     nonContractAccountWallet = new SignerlessWallet(pxe);
 
@@ -59,4 +59,24 @@ describe('e2e_non_contract_account', () => {
     const msgSender = toBigInt(logs[0].log.data);
     expect(msgSender).toBe(0n);
   }, 120_000);
+
+  // Note: This test doesn't really belong here as it doesn't have anything to do with non-contract accounts. I needed
+  // to test the FieldNote functionality and it doesn't really fit anywhere else. Creating a separate e2e test for this
+  // seems wasteful. Move this test if a better place is found.
+  it('can set and get a constant', async () => {
+    const value = 123n;
+
+    const receipt = await contract.methods.set_constant(value).send().wait({ interval: 0.1 });
+
+    // check that 1 commitment was created
+    const tx = await pxe.getTx(receipt.txHash);
+    const nonZeroCommitments = tx?.newCommitments.filter(c => c.value > 0);
+    expect(nonZeroCommitments?.length).toBe(1);
+
+    // Add the note
+    const preimage = new NotePreimage([new Fr(value)]);
+    await wallet.addNote(wallet.getCompleteAddress().address, contract.address, new Fr(1), preimage, receipt.txHash);
+
+    expect(await contract.methods.get_constant().view()).toEqual(value);
+  });
 });

yarn-project/noir-contracts/src/contracts/import_test_contract/src/main.nr

@@ -32,15 +32,15 @@ contract ImportTest {
             true,
             1 as u32,
             [1, 2],
-            AStructTestCodeGenStruct { amount: 1, secretHash: 2 },
+            AStructTestCodeGenStruct { amount: 1, secret_hash: 2 },
             ADeepStructTestCodeGenStruct {
-                aField: 1, 
-                aBool: true, 
-                aNote: ANoteADeepStructTestCodeGenStruct { amount: 1, secretHash: 2 },
-                manyNotes: [
-                    ManyNotesADeepStructTestCodeGenStruct { amount: 1, secretHash: 2 },
-                    ManyNotesADeepStructTestCodeGenStruct { amount: 1, secretHash: 2 },
-                    ManyNotesADeepStructTestCodeGenStruct { amount: 1, secretHash: 2 },
+                a_field: 1, 
+                a_bool: true, 
+                a_note: ANoteADeepStructTestCodeGenStruct { amount: 1, secret_hash: 2 },
+                many_notes: [
+                    ManyNotesADeepStructTestCodeGenStruct { amount: 1, secret_hash: 2 },
+                    ManyNotesADeepStructTestCodeGenStruct { amount: 1, secret_hash: 2 },
+                    ManyNotesADeepStructTestCodeGenStruct { amount: 1, secret_hash: 2 },
                 ]
             }
         );

yarn-project/noir-contracts/src/contracts/test_contract/Nargo.toml

@@ -6,4 +6,5 @@ type = "contract"
 
 [dependencies]
 aztec = { path = "../../../../aztec-nr/aztec" }
+field_note = { path = "../../../../aztec-nr/field-note" }
 token_portal_content_hash_lib = { path = "../token_portal_content_hash_lib" }

yarn-project/noir-contracts/src/contracts/test_contract/src/interface.nr

@@ -6,24 +6,24 @@ use dep::aztec::constants_gen::RETURN_VALUES_LENGTH;
 
 struct AStructTestCodeGenStruct {
   amount: Field,
-  secretHash: Field,
+  secret_hash: Field,
 }
 
 struct ADeepStructTestCodeGenStruct {
-  aField: Field,
-  aBool: bool,
-  aNote: ANoteADeepStructTestCodeGenStruct,
-  manyNotes: [ManyNotesADeepStructTestCodeGenStruct;3],
+  a_field: Field,
+  a_bool: bool,
+  a_note: ANoteADeepStructTestCodeGenStruct,
+  many_notes: [ManyNotesADeepStructTestCodeGenStruct;3],
 }
 
 struct ANoteADeepStructTestCodeGenStruct {
   amount: Field,
-  secretHash: Field,
+  secret_hash: Field,
 }
 
 struct ManyNotesADeepStructTestCodeGenStruct {
   amount: Field,
-  secretHash: Field,
+  secret_hash: Field,
 }
 
 
@@ -83,11 +83,11 @@ impl TestPrivateContextInterface {
     self,
     context: &mut PrivateContext,
     amount: Field,
-    secretHash: Field
+    secret_hash: Field
   ) {
     let mut serialized_args = [0; 2];
     serialized_args[0] = amount;
-    serialized_args[1] = secretHash;
+    serialized_args[1] = secret_hash;
 
     context.call_public_function(self.address, 0x9749ca06, serialized_args)
   }
@@ -97,11 +97,11 @@ impl TestPrivateContextInterface {
     self,
     context: &mut PrivateContext,
     amount: Field,
-    secretHash: Field
+    secret_hash: Field
   ) {
     let mut serialized_args = [0; 2];
     serialized_args[0] = amount;
-    serialized_args[1] = secretHash;
+    serialized_args[1] = secret_hash;
 
     context.call_public_function(self.address, 0xdf02db8d, serialized_args)
   }
@@ -197,34 +197,46 @@ impl TestPrivateContextInterface {
   }
 
 
+  pub fn set_constant(
+    self,
+    context: &mut PrivateContext,
+    value: Field
+  ) -> [Field; RETURN_VALUES_LENGTH] {
+    let mut serialized_args = [0; 1];
+    serialized_args[0] = value;
+
+    context.call_private_function(self.address, 0x1b3b9e18, serialized_args)
+  }
+
+
   pub fn test_code_gen(
     self,
     context: &mut PrivateContext,
-    aField: Field,
-    aBool: bool,
-    aNumber: u32,
-    anArray: [Field;2],
-    aStruct: AStructTestCodeGenStruct,
-    aDeepStruct: ADeepStructTestCodeGenStruct
+    a_field: Field,
+    a_bool: bool,
+    a_number: u32,
+    an_array: [Field;2],
+    a_struct: AStructTestCodeGenStruct,
+    a_deep_struct: ADeepStructTestCodeGenStruct
   ) -> [Field; RETURN_VALUES_LENGTH] {
     let mut serialized_args = [0; 17];
-    serialized_args[0] = aField;
-    serialized_args[1] = aBool as Field;
-    serialized_args[2] = aNumber as Field;
-    serialized_args[3] = anArray[0];
-    serialized_args[4] = anArray[1];
-    serialized_args[5] = aStruct.amount;
-    serialized_args[6] = aStruct.secretHash;
-    serialized_args[7] = aDeepStruct.aField;
-    serialized_args[8] = aDeepStruct.aBool as Field;
-    serialized_args[9] = aDeepStruct.aNote.amount;
-    serialized_args[10] = aDeepStruct.aNote.secretHash;
-    serialized_args[11] = aDeepStruct.manyNotes[0].amount;
-    serialized_args[12] = aDeepStruct.manyNotes[0].secretHash;
-    serialized_args[13] = aDeepStruct.manyNotes[1].amount;
-    serialized_args[14] = aDeepStruct.manyNotes[1].secretHash;
-    serialized_args[15] = aDeepStruct.manyNotes[2].amount;
-    serialized_args[16] = aDeepStruct.manyNotes[2].secretHash;
+    serialized_args[0] = a_field;
+    serialized_args[1] = a_bool as Field;
+    serialized_args[2] = a_number as Field;
+    serialized_args[3] = an_array[0];
+    serialized_args[4] = an_array[1];
+    serialized_args[5] = a_struct.amount;
+    serialized_args[6] = a_struct.secret_hash;
+    serialized_args[7] = a_deep_struct.a_field;
+    serialized_args[8] = a_deep_struct.a_bool as Field;
+    serialized_args[9] = a_deep_struct.a_note.amount;
+    serialized_args[10] = a_deep_struct.a_note.secret_hash;
+    serialized_args[11] = a_deep_struct.many_notes[0].amount;
+    serialized_args[12] = a_deep_struct.many_notes[0].secret_hash;
+    serialized_args[13] = a_deep_struct.many_notes[1].amount;
+    serialized_args[14] = a_deep_struct.many_notes[1].secret_hash;
+    serialized_args[15] = a_deep_struct.many_notes[2].amount;
+    serialized_args[16] = a_deep_struct.many_notes[2].secret_hash;
 
     context.call_private_function(self.address, 0x0f054f9b, serialized_args)
   }
@@ -270,11 +282,11 @@ impl TestPublicContextInterface {
     self,
     context: PublicContext,
     amount: Field,
-    secretHash: Field
+    secret_hash: Field
   ) -> [Field; RETURN_VALUES_LENGTH] {
     let mut serialized_args = [0; 2];
     serialized_args[0] = amount;
-    serialized_args[1] = secretHash;
+    serialized_args[1] = secret_hash;
 
     context.call_public_function(self.address, 0x9749ca06, serialized_args)
   }
@@ -284,11 +296,11 @@ impl TestPublicContextInterface {
     self,
     context: PublicContext,
     amount: Field,
-    secretHash: Field
+    secret_hash: Field
   ) -> [Field; RETURN_VALUES_LENGTH] {
     let mut serialized_args = [0; 2];
     serialized_args[0] = amount;
-    serialized_args[1] = secretHash;
+    serialized_args[1] = secret_hash;
 
     context.call_public_function(self.address, 0xdf02db8d, serialized_args)
   }