feat: add js tests (#361)

# 🤖 Linear

Closes AZT-XXX

## Description 
add js tests

Author: 0xLeopoldo

src/ts/test/multitoken.test.ts

@@ -0,0 +1,369 @@
+import { Fr } from '@aztec/aztec.js/fields';
+import { AztecAddress } from '@aztec/aztec.js/addresses';
+import { type EmbeddedWallet } from '@aztec/wallets/embedded';
+import { SetPublicAuthwitContractInteraction, lookupValidity } from '@aztec/aztec.js/authorization';
+import { type ContractFunctionInteractionCallIntent } from '@aztec/aztec.js/authorization';
+
+import { describe, it, expect, beforeAll, beforeEach, afterAll } from 'vitest';
+
+import {
+  setupTestSuite,
+  AMOUNT,
+  PRIVATE_ADDRESS,
+  MULTITOKEN_NAME,
+  MULTITOKEN_SYMBOL,
+  ID_A,
+  fieldFromShortString,
+  compressedStringToBigInt,
+  deployMultiTokenWithMinter,
+  initializeMultiTokenTransferCommitment,
+  expectMultiTokenTransferEvents,
+} from './utils.js';
+
+import { MultiTokenContract } from '../../../src/artifacts/MultiToken.js';
+
+const TEST_TIMEOUT = 300_000;
+
+// Scope of this suite: ONE end-to-end happy-path per main (state-mutating) function, exercised through
+// the real client stack (deploy -> call -> read via SDK, with real authwit + additionalScopes), asserting
+// the resulting balances and the decoded event. It answers "does each function work end-to-end?".
+// Correctness details — reverts, overflow/underflow, per-id isolation, id=0, note lifecycle, the ARC-403
+// authorization hook, boundaries — are covered by the Noir/TXE suite (src/multitoken_contract/src/test/*).
+describe('MultiToken', () => {
+  let cleanup: () => Promise<void>;
+
+  let wallet: EmbeddedWallet;
+  let accounts: AztecAddress[];
+
+  let alice: AztecAddress;
+  let bob: AztecAddress;
+  let carl: AztecAddress;
+
+  let multitoken: MultiTokenContract;
+
+  beforeAll(async () => {
+    ({ cleanup, wallet, accounts } = await setupTestSuite());
+
+    [alice, bob, carl] = accounts;
+  });
+
+  beforeEach(async () => {
+    // Default deploy: minter = alice, auth_contract = ZERO (ARC-403 hook disabled). The hook's behavior
+    // is covered exhaustively by the Noir suite (authorization.nr); here every path runs with it off.
+    multitoken = await deployMultiTokenWithMinter(wallet, alice, alice, AztecAddress.ZERO);
+  });
+
+  afterAll(async () => {
+    await cleanup();
+  });
+
+  // --- deploy / views ---
+
+  it(
+    'deploys with a minter and reads back name/symbol/minter/auth_contract',
+    async () => {
+      const nameField = fieldFromShortString(MULTITOKEN_NAME);
+      const symbolField = fieldFromShortString(MULTITOKEN_SYMBOL);
+
+      const mt = await deployMultiTokenWithMinter(wallet, alice, alice, AztecAddress.ZERO);
+
+      const nameResult = (await mt.methods.name().simulate({ from: alice })).result;
+      const symbolResult = (await mt.methods.symbol().simulate({ from: alice })).result;
+      expect(compressedStringToBigInt(nameResult)).toBe(nameField.toBigInt());
+      expect(compressedStringToBigInt(symbolResult)).toBe(symbolField.toBigInt());
+
+      const minter = (await mt.methods.get_minter().simulate({ from: alice })).result;
+      expect(minter.equals(alice)).toBe(true);
+
+      const authContract = (await mt.methods.get_auth_contract().simulate({ from: alice })).result;
+      expect(authContract.equals(AztecAddress.ZERO)).toBe(true);
+    },
+    TEST_TIMEOUT,
+  );
+
+  // --- mint_to_private ---
+
+  it(
+    'mints to a private recipient balance and leaks nothing publicly',
+    async () => {
+      const id = ID_A;
+      const { receipt: mintTx } = await multitoken.methods.mint_to_private(bob, id, AMOUNT).send({ from: alice });
+      // mint_to_private: (no public events)
+      await expectMultiTokenTransferEvents(mintTx.txHash, multitoken.address, []);
+      // recipient sees its private balance; no public balance was written.
+      expect((await multitoken.methods.balance_of_private(bob, id).simulate({ from: bob })).result).toBe(AMOUNT);
+      expect((await multitoken.methods.balance_of_public(bob, id).simulate({ from: bob })).result).toBe(0n);
+      // an uninvolved third party never observes another account's private notes.
+      expect((await multitoken.methods.balance_of_private(bob, id).simulate({ from: carl })).result).toBe(0n);
+    },
+    TEST_TIMEOUT,
+  );
+
+  // --- mint_to_public ---
+
+  it(
+    'mints to public and emits a 4-field TransferSingle event',
+    async () => {
+      const id = ID_A;
+
+      const { receipt: mintTx } = await multitoken.methods.mint_to_public(alice, id, AMOUNT).send({ from: alice });
+
+      // mint_to_public: TransferSingle(0x0, alice, id, AMOUNT)
+      await expectMultiTokenTransferEvents(mintTx.txHash, multitoken.address, [
+        { from: AztecAddress.ZERO, to: alice, id, amount: AMOUNT },
+      ]);
+
+      expect((await multitoken.methods.balance_of_public(alice, id).simulate({ from: alice })).result).toBe(AMOUNT);
+      // No private note written for the public mint.
+      expect((await multitoken.methods.balance_of_private(alice, id).simulate({ from: alice })).result).toBe(0n);
+    },
+    TEST_TIMEOUT,
+  );
+
+  // --- mint_to_commitment ---
+
+  it(
+    'mints to a recipient-prepared commitment and credits the recipient privately',
+    async () => {
+      const id = ID_A;
+
+      // Recipient (bob) prepares the commitment for himself in his own settled tx, bound to the minter (alice) as completer.
+      const commitment = await initializeMultiTokenTransferCommitment(multitoken, bob, bob, alice);
+
+      // Minter (alice = msg_sender) completes the commitment by minting into it.
+      const { receipt: mintTx } = await multitoken.methods
+        .mint_to_commitment(id, commitment, AMOUNT)
+        .send({ from: alice });
+
+      // mint_to_commitment: TransferSingle(0x0, PRIVATE, id, AMOUNT)
+      await expectMultiTokenTransferEvents(mintTx.txHash, multitoken.address, [
+        { from: AztecAddress.ZERO, to: PRIVATE_ADDRESS, id, amount: AMOUNT },
+      ]);
+
+      // bob holds the tokens privately for this id.
+      expect((await multitoken.methods.balance_of_private(bob, id).simulate({ from: bob })).result).toBe(AMOUNT);
+    },
+    TEST_TIMEOUT,
+  );
+
+  // --- transfer_public_to_public (happy-path carries the PUBLIC authwit demo) ---
+
+  it(
+    'transfers public to public with a public authwit',
+    async () => {
+      const id = ID_A;
+
+      const { receipt: mintTx } = await multitoken
+        .withWallet(wallet)
+        .methods.mint_to_public(alice, id, AMOUNT)
+        .send({ from: alice });
+
+      // mint_to_public: TransferSingle(0x0, alice, id, AMOUNT)
+      await expectMultiTokenTransferEvents(mintTx.txHash, multitoken.address, [
+        { from: AztecAddress.ZERO, to: alice, id, amount: AMOUNT },
+      ]);
+
+      // Build the transfer; carl will submit it under alice's public authwit.
+      const nonce = Fr.random();
+      const action = multitoken.withWallet(wallet).methods.transfer_public_to_public(alice, bob, id, AMOUNT, nonce);
+
+      const intent: ContractFunctionInteractionCallIntent = {
+        caller: carl,
+        action,
+      };
+      const authWitness = await wallet.createAuthWit(alice, {
+        caller: intent.caller,
+        call: await intent.action.getFunctionCall(),
+      });
+      const setPublicAuthwitInteraction = await SetPublicAuthwitContractInteraction.create(wallet, alice, intent, true);
+      await setPublicAuthwitInteraction.send();
+
+      const validity = await lookupValidity(wallet, alice, intent, authWitness);
+      expect(validity.isValidInPrivate).toBeTruthy();
+      expect(validity.isValidInPublic).toBeTruthy();
+
+      const { receipt: transferTx } = await action.send({ from: carl, authWitnesses: [authWitness] });
+
+      // transfer_public_to_public: TransferSingle(alice, bob, id, AMOUNT)
+      await expectMultiTokenTransferEvents(transferTx.txHash, multitoken.address, [
+        { from: alice, to: bob, id, amount: AMOUNT },
+      ]);
+
+      expect((await multitoken.methods.balance_of_public(alice, id).simulate({ from: carl })).result).toBe(0n);
+      expect((await multitoken.methods.balance_of_public(bob, id).simulate({ from: carl })).result).toBe(AMOUNT);
+    },
+    TEST_TIMEOUT,
+  );
+
+  // --- transfer_public_to_private (happy-path carries the PRIVATE authwit + additionalScopes demo) ---
+
+  it(
+    'transfers public to private under a third-party private authwit with additionalScopes',
+    async () => {
+      const id = ID_A;
+
+      await multitoken.methods.mint_to_public(alice, id, AMOUNT).send({ from: alice });
+
+      // Third party (bob) submits alice -> carl spending alice's PUBLIC balance; gate is a private authwit by alice.
+      const action = multitoken.methods.transfer_public_to_private(alice, carl, id, AMOUNT, 1n);
+
+      const intent: ContractFunctionInteractionCallIntent = {
+        caller: bob,
+        action,
+      };
+      const witness = await wallet.createAuthWit(alice, {
+        caller: intent.caller,
+        call: await intent.action.getFunctionCall(),
+      });
+
+      // additionalScopes includes alice so bob's PXE can read alice's account-contract notes
+      // (signing key) needed for private authwit verification.
+      const { receipt: transferTx } = await action.send({
+        from: bob,
+        authWitnesses: [witness],
+        additionalScopes: [alice],
+      });
+
+      // transfer_public_to_private: TransferSingle(alice, PRIVATE, id, AMOUNT)  (hidden recipient side is the sentinel)
+      await expectMultiTokenTransferEvents(transferTx.txHash, multitoken.address, [
+        { from: alice, to: PRIVATE_ADDRESS, id, amount: AMOUNT },
+      ]);
+
+      expect((await multitoken.methods.balance_of_public(alice, id).simulate({ from: bob })).result).toBe(0n);
+      expect((await multitoken.methods.balance_of_private(carl, id).simulate({ from: carl })).result).toBe(AMOUNT);
+    },
+    TEST_TIMEOUT,
+  );
+
+  // --- transfer_public_to_commitment ---
+
+  it(
+    'transfers public to a recipient commitment as a self-spend',
+    async () => {
+      const id = ID_A;
+      // bob prepares the commitment for himself in his own settled tx, bound to alice (the payer) as completer.
+      const commitment = await initializeMultiTokenTransferCommitment(multitoken, bob, bob, alice);
+      await multitoken.methods.mint_to_public(alice, id, AMOUNT).send({ from: alice });
+      const { receipt: transferTx } = await multitoken.methods
+        .transfer_public_to_commitment(alice, id, commitment, AMOUNT, 0)
+        .send({ from: alice });
+      // transfer_public_to_commitment: TransferSingle(alice, PRIVATE, id, AMOUNT)
+      await expectMultiTokenTransferEvents(transferTx.txHash, multitoken.address, [
+        { from: alice, to: PRIVATE_ADDRESS, id, amount: AMOUNT },
+      ]);
+      expect((await multitoken.methods.balance_of_public(alice, id).simulate({ from: alice })).result).toBe(0n);
+      expect((await multitoken.methods.balance_of_private(bob, id).simulate({ from: bob })).result).toBe(AMOUNT);
+    },
+    TEST_TIMEOUT,
+  );
+
+  // --- transfer_private_to_private ---
+
+  it(
+    'transfers private to private as a self-spend and leaks nothing publicly',
+    async () => {
+      const id = ID_A;
+      await multitoken.methods.mint_to_private(alice, id, AMOUNT).send({ from: alice });
+      const { receipt: transferTx } = await multitoken.methods
+        .transfer_private_to_private(alice, bob, id, AMOUNT, 0)
+        .send({ from: alice });
+      // transfer_private_to_private: (no public events)
+      await expectMultiTokenTransferEvents(transferTx.txHash, multitoken.address, []);
+      expect((await multitoken.methods.balance_of_private(alice, id).simulate({ from: alice })).result).toBe(0n);
+      expect((await multitoken.methods.balance_of_private(bob, id).simulate({ from: bob })).result).toBe(AMOUNT);
+      expect((await multitoken.methods.balance_of_public(alice, id).simulate({ from: alice })).result).toBe(0n);
+      expect((await multitoken.methods.balance_of_public(bob, id).simulate({ from: alice })).result).toBe(0n);
+      // Third party never observes bob's new private notes.
+      expect((await multitoken.methods.balance_of_private(bob, id).simulate({ from: carl })).result).toBe(0n);
+    },
+    TEST_TIMEOUT,
+  );
+
+  // --- transfer_private_to_public ---
+
+  it(
+    'transfers private to public as a self-spend and credits the recipient publicly',
+    async () => {
+      const id = ID_A;
+      await multitoken.methods.mint_to_private(alice, id, AMOUNT).send({ from: alice });
+      const { receipt: transferTx } = await multitoken.methods
+        .transfer_private_to_public(alice, bob, id, AMOUNT, 0)
+        .send({ from: alice });
+      // transfer_private_to_public: TransferSingle(PRIVATE, bob, id, AMOUNT)
+      await expectMultiTokenTransferEvents(transferTx.txHash, multitoken.address, [
+        { from: PRIVATE_ADDRESS, to: bob, id, amount: AMOUNT },
+      ]);
+      expect((await multitoken.methods.balance_of_private(alice, id).simulate({ from: alice })).result).toBe(0n);
+      expect((await multitoken.methods.balance_of_public(bob, id).simulate({ from: alice })).result).toBe(AMOUNT);
+    },
+    TEST_TIMEOUT,
+  );
+
+  // --- transfer_private_to_commitment ---
+
+  it(
+    'transfers private to a settled commitment as a self-spend with no public event',
+    async () => {
+      const id = ID_A;
+      // bob prepares the commitment for himself in a PRIOR settled tx, bound to alice (payer) as completer.
+      // complete_from_private requires the validity commitment to be from a prior settled tx (the helper settles it).
+      const commitment = await initializeMultiTokenTransferCommitment(multitoken, bob, bob, alice);
+      await multitoken.methods.mint_to_private(alice, id, AMOUNT).send({ from: alice });
+      const { receipt: transferTx } = await multitoken.methods
+        .transfer_private_to_commitment(alice, id, commitment, AMOUNT, 0)
+        .send({ from: alice });
+      // transfer_private_to_commitment: (no public events) — private completion uses a private log, not a public write.
+      await expectMultiTokenTransferEvents(transferTx.txHash, multitoken.address, []);
+      expect((await multitoken.methods.balance_of_private(alice, id).simulate({ from: alice })).result).toBe(0n);
+      expect((await multitoken.methods.balance_of_private(bob, id).simulate({ from: bob })).result).toBe(AMOUNT);
+    },
+    TEST_TIMEOUT,
+  );
+
+  // --- burn_private ---
+
+  it(
+    'burns from a private balance as a self-spend',
+    async () => {
+      const id = ID_A;
+      await multitoken.methods.mint_to_private(alice, id, AMOUNT).send({ from: alice });
+      await multitoken.methods.burn_private(alice, id, AMOUNT, 0).send({ from: alice });
+      expect((await multitoken.methods.balance_of_private(alice, id).simulate({ from: alice })).result).toBe(0n);
+      expect((await multitoken.methods.balance_of_public(alice, id).simulate({ from: alice })).result).toBe(0n);
+    },
+    TEST_TIMEOUT,
+  );
+
+  // --- burn_public ---
+
+  it(
+    'burns from a public balance and emits a burn event',
+    async () => {
+      const id = ID_A;
+      await multitoken.methods.mint_to_public(alice, id, AMOUNT).send({ from: alice });
+      const { receipt: burnTx } = await multitoken.methods.burn_public(alice, id, AMOUNT, 0).send({ from: alice });
+      // burn_public: TransferSingle(alice, 0x0, id, AMOUNT)
+      await expectMultiTokenTransferEvents(burnTx.txHash, multitoken.address, [
+        { from: alice, to: AztecAddress.ZERO, id, amount: AMOUNT },
+      ]);
+      expect((await multitoken.methods.balance_of_public(alice, id).simulate({ from: alice })).result).toBe(0n);
+    },
+    TEST_TIMEOUT,
+  );
+
+  // --- initialize_transfer_commitment ---
+
+  it(
+    'initializes a transfer commitment (non-zero, no authwit, no balance change)',
+    async () => {
+      const id = ID_A;
+      // Uses the sanctioned wallet-internals commitment helper (the ONLY sanctioned PXE/wallet-internals escape hatch).
+      const commitment = await initializeMultiTokenTransferCommitment(multitoken, alice, bob, alice);
+      expect(commitment).not.toBe(0n);
+      // No id is bound at initialization; no balance is credited to the recipient or completer.
+      expect((await multitoken.methods.balance_of_private(bob, id).simulate({ from: bob })).result).toBe(0n);
+      expect((await multitoken.methods.balance_of_public(bob, id).simulate({ from: bob })).result).toBe(0n);
+    },
+    TEST_TIMEOUT,
+  );
+});