test: add unit tests and minor fixes

contracts/finance/ConfidentialVestingWallet.sol

@@ -5,8 +5,6 @@ import "fhevm/lib/TFHE.sol";
 
 import { IConfidentialERC20 } from "../token/ERC20/IConfidentialERC20.sol";
 
-import "hardhat/console.sol";
-
 /**
  * @title  ConfidentialVestingWallet
  * @notice This contract offers a simple vesting wallet for ConfidentialERC20 tokens.
@@ -36,9 +34,8 @@ abstract contract ConfidentialVestingWallet {
 
     /// @notice Constant for zero using TFHE.
     /// @dev    Since it is expensive to compute 0, it is stored instead.
-    ///         However, is not possible to define it as constant due to TFHE constraints.
     /* solhint-disable var-name-mixedcase*/
-    euint64 internal _EUINT64_ZERO;
+    euint64 internal immutable _EUINT64_ZERO;
 
     /// @notice Total encrypted amount released (to the beneficiary).
     euint64 internal _amountReleased;
@@ -56,7 +53,7 @@ abstract contract ConfidentialVestingWallet {
         END_TIMESTAMP = startTimestamp_ + duration_;
         BENEFICIARY = beneficiary_;
 
-        /// @dev Store this constant-like variable in the storage.
+        /// @dev Store this constant variable in the storage.
         _EUINT64_ZERO = TFHE.asEuint64(0);
         _amountReleased = _EUINT64_ZERO;
 
@@ -70,12 +67,11 @@ abstract contract ConfidentialVestingWallet {
      */
     function release() public virtual {
         euint64 amount = _releasable();
-
         euint64 amountReleased = TFHE.add(_amountReleased, amount);
         _amountReleased = amountReleased;
+
         TFHE.allow(amountReleased, BENEFICIARY);
         TFHE.allowThis(amountReleased);
-
         TFHE.allowTransient(amount, address(CONFIDENTIAL_ERC20));
         CONFIDENTIAL_ERC20.transfer(BENEFICIARY, amount);
 

contracts/finance/ConfidentialVestingWalletCliff.sol

@@ -13,33 +13,32 @@ import { ConfidentialVestingWallet } from "./ConfidentialVestingWallet.sol";
  * @dev    This implementation is a linear vesting curve with a cliff.
  *         To use with the native asset, it is necessary to wrap the native asset to a ConfidentialERC20-like token.
  */
-
-abstract contract VestingWalletCliff is ConfidentialVestingWallet {
+abstract contract ConfidentialVestingWalletCliff is ConfidentialVestingWallet {
     /// @notice Returned if the cliff duration is greater than the vesting duration.
     error InvalidCliffDuration(uint64 cliffSeconds, uint64 durationSeconds);
 
-    /// @notice Cliff duration (in seconds).
+    /// @notice Cliff timestamp.
     uint64 public immutable CLIFF;
 
     /**
      * @param beneficiary_      Beneficiary address.
      * @param token_            Confidential token address.
      * @param startTimestamp_   Start timestamp.
      * @param duration_         Duration (in seconds).
-     * @param cliff_            Cliff (in seconds).
+     * @param cliffSeconds_     Cliff (in seconds).
      */
     constructor(
         address beneficiary_,
         address token_,
         uint64 startTimestamp_,
         uint64 duration_,
-        uint64 cliff_
+        uint64 cliffSeconds_
     ) ConfidentialVestingWallet(beneficiary_, token_, startTimestamp_, duration_) {
-        if (cliff_ > duration_) {
-            revert InvalidCliffDuration(cliff_, duration_);
+        if (cliffSeconds_ > duration_) {
+            revert InvalidCliffDuration(cliffSeconds_, duration_);
         }
 
-        CLIFF = startTimestamp_ + cliff_;
+        CLIFF = startTimestamp_ + cliffSeconds_;
     }
 
     /**

contracts/test/finance/TestConfidentialVestingWallet.sol

@@ -0,0 +1,16 @@
+// SPDX-License-Identifier: BSD-3-Clause-Clear
+pragma solidity ^0.8.24;
+
+import { ConfidentialVestingWallet } from "../../finance/ConfidentialVestingWallet.sol";
+import { SepoliaZamaFHEVMConfig } from "fhevm/config/ZamaFHEVMConfig.sol";
+
+contract TestConfidentialVestingWallet is SepoliaZamaFHEVMConfig, ConfidentialVestingWallet {
+    constructor(
+        address beneficiary_,
+        address token_,
+        uint64 startTimestamp_,
+        uint64 duration_
+    ) ConfidentialVestingWallet(beneficiary_, token_, startTimestamp_, duration_) {
+        //
+    }
+}

contracts/test/finance/TestConfidentialVestingWalletCliff.sol

@@ -0,0 +1,17 @@
+// SPDX-License-Identifier: BSD-3-Clause-Clear
+pragma solidity ^0.8.24;
+
+import { ConfidentialVestingWalletCliff } from "../../finance/ConfidentialVestingWalletCliff.sol";
+import { SepoliaZamaFHEVMConfig } from "fhevm/config/ZamaFHEVMConfig.sol";
+
+contract TestConfidentialVestingWalletCliff is SepoliaZamaFHEVMConfig, ConfidentialVestingWalletCliff {
+    constructor(
+        address beneficiary_,
+        address token_,
+        uint64 startTimestamp_,
+        uint64 duration_,
+        uint64 cliff_
+    ) ConfidentialVestingWalletCliff(beneficiary_, token_, startTimestamp_, duration_, cliff_) {
+        //
+    }
+}

test/finance/ConfidentialVestingWallet.fixture.ts

@@ -0,0 +1,30 @@
+import { Signer } from "ethers";
+import { FhevmInstance } from "fhevmjs/node";
+import { ethers } from "hardhat";
+
+import type { ConfidentialVestingWallet, TestConfidentialVestingWallet } from "../../types";
+import { reencryptEuint64 } from "../reencrypt";
+
+export async function deployConfidentialVestingWalletFixture(
+  account: Signer,
+  beneficiaryAddress: string,
+  token: string,
+  startTimestamp: bigint,
+  duration: bigint,
+): Promise<TestConfidentialVestingWallet> {
+  const contractFactory = await ethers.getContractFactory("TestConfidentialVestingWallet");
+  const contract = await contractFactory.connect(account).deploy(beneficiaryAddress, token, startTimestamp, duration);
+  await contract.waitForDeployment();
+  return contract;
+}
+
+export async function reencryptReleased(
+  account: Signer,
+  instance: FhevmInstance,
+  vestingWallet: ConfidentialVestingWallet,
+  vestingWalletAddress: string,
+): Promise<bigint> {
+  const releasedHandled = await vestingWallet.released();
+  const releasedAmount = await reencryptEuint64(account, instance, releasedHandled, vestingWalletAddress);
+  return releasedAmount;
+}

test/finance/ConfidentialVestingWallet.test.ts

@@ -0,0 +1,158 @@
+import { expect } from "chai";
+import { parseUnits } from "ethers";
+import { ethers } from "hardhat";
+
+import { deployConfidentialERC20Fixture, reencryptBalance } from "../confidentialERC20/ConfidentialERC20.fixture";
+import { createInstance } from "../instance";
+import { getSigners, initSigners } from "../signers";
+import { deployConfidentialVestingWalletFixture, reencryptReleased } from "./ConfidentialVestingWallet.fixture";
+
+describe("ConfidentialVestingWallet", function () {
+  before(async function () {
+    await initSigners();
+    this.signers = await getSigners();
+    this.instance = await createInstance();
+  });
+
+  beforeEach(async function () {
+    const latestBlockNumber = await ethers.provider.getBlockNumber();
+    const block = await ethers.provider.getBlock(latestBlockNumber);
+
+    this.beneficiary = this.signers.bob;
+    this.beneficiaryAddress = this.signers.bob.address;
+
+    const contractConfidentialERC20 = await deployConfidentialERC20Fixture(
+      this.signers.alice,
+      "Naraggara",
+      "NARA",
+      this.signers.alice.address,
+    );
+    this.confidentialERC20Address = await contractConfidentialERC20.getAddress();
+    this.confidentialERC20 = contractConfidentialERC20;
+    this.startTimestamp = BigInt(block!.timestamp + 3600);
+    this.duration = BigInt(36_000); // 36,000 seconds
+
+    const contractConfidentialVestingWallet = await deployConfidentialVestingWalletFixture(
+      this.signers.alice,
+      this.beneficiaryAddress,
+      this.confidentialERC20Address,
+      this.startTimestamp,
+      this.duration,
+    );
+
+    this.confidentialVestingWallet = contractConfidentialVestingWallet;
+    this.confidentialVestingWalletAddress = await contractConfidentialVestingWallet.getAddress();
+  });
+
+  it("post-deployment state", async function () {
+    expect(await this.confidentialVestingWallet.BENEFICIARY()).to.equal(this.beneficiaryAddress);
+    expect(await this.confidentialVestingWallet.CONFIDENTIAL_ERC20()).to.equal(this.confidentialERC20);
+    expect(await this.confidentialVestingWallet.DURATION()).to.equal(this.duration);
+    expect(await this.confidentialVestingWallet.END_TIMESTAMP()).to.be.eq(this.startTimestamp + this.duration);
+    expect(await this.confidentialVestingWallet.START_TIMESTAMP()).to.be.eq(this.startTimestamp);
+    expect(
+      await reencryptReleased(
+        this.beneficiary,
+        this.instance,
+        this.confidentialVestingWallet,
+        this.confidentialVestingWalletAddress,
+      ),
+    ).to.be.eq(0n);
+  });
+
+  it("can release", async function () {
+    // 10M
+    const amount = parseUnits("10000000", 6);
+
+    let tx = await this.confidentialERC20.connect(this.signers.alice).mint(this.signers.alice, amount);
+    await tx.wait();
+
+    const input = this.instance.createEncryptedInput(this.confidentialERC20Address, this.signers.alice.address);
+    input.add64(amount);
+    const encryptedTransferAmount = await input.encrypt();
+
+    tx = await this.confidentialERC20
+      .connect(this.signers.alice)
+      [
+        "transfer(address,bytes32,bytes)"
+      ](this.confidentialVestingWalletAddress, encryptedTransferAmount.handles[0], encryptedTransferAmount.inputProof);
+
+    await tx.wait();
+
+    let nextTimestamp = this.startTimestamp;
+    await ethers.provider.send("evm_setNextBlockTimestamp", [nextTimestamp.toString()]);
+
+    tx = await this.confidentialVestingWallet.connect(this.beneficiary).release();
+    await expect(tx).to.emit(this.confidentialVestingWallet, "ConfidentialERC20Released");
+
+    // It should be equal to 0 because the vesting has not started.
+    expect(
+      await reencryptReleased(
+        this.beneficiary,
+        this.instance,
+        this.confidentialVestingWallet,
+        this.confidentialVestingWalletAddress,
+      ),
+    ).to.be.eq(0n);
+
+    nextTimestamp = this.startTimestamp + this.duration / BigInt(4);
+    await ethers.provider.send("evm_setNextBlockTimestamp", [nextTimestamp.toString()]);
+
+    tx = await this.confidentialVestingWallet.connect(this.beneficiary).release();
+    await tx.wait();
+
+    // It should be equal to 1/4 of the amount vested.
+    expect(
+      await reencryptReleased(
+        this.beneficiary,
+        this.instance,
+        this.confidentialVestingWallet,
+        this.confidentialVestingWalletAddress,
+      ),
+    ).to.be.eq(BigInt(amount) / BigInt(4));
+
+    expect(
+      await reencryptBalance(this.beneficiary, this.instance, this.confidentialERC20, this.confidentialERC20Address),
+    ).to.be.eq(BigInt(amount) / BigInt(4));
+
+    nextTimestamp = this.startTimestamp + this.duration / BigInt(2);
+    await ethers.provider.send("evm_setNextBlockTimestamp", [nextTimestamp.toString()]);
+
+    tx = await this.confidentialVestingWallet.connect(this.beneficiary).release();
+    await tx.wait();
+
+    // It should be equal to 1/4 of the amount vested since 1/4 was already collected.
+    expect(
+      await reencryptReleased(
+        this.beneficiary,
+        this.instance,
+        this.confidentialVestingWallet,
+        this.confidentialVestingWalletAddress,
+      ),
+    ).to.be.eq(BigInt(amount) / BigInt(2));
+
+    expect(
+      await reencryptBalance(this.beneficiary, this.instance, this.confidentialERC20, this.confidentialERC20Address),
+    ).to.be.eq(BigInt(amount) / BigInt(2));
+
+    nextTimestamp = this.startTimestamp + this.duration;
+    await ethers.provider.send("evm_setNextBlockTimestamp", [nextTimestamp.toString()]);
+
+    tx = await this.confidentialVestingWallet.connect(this.beneficiary).release();
+    await tx.wait();
+
+    // It should be equal to 1/2 of the amount vested since 2/4 was already collected.
+    expect(
+      await reencryptReleased(
+        this.beneficiary,
+        this.instance,
+        this.confidentialVestingWallet,
+        this.confidentialVestingWalletAddress,
+      ),
+    ).to.be.eq(BigInt(amount));
+
+    expect(
+      await reencryptBalance(this.beneficiary, this.instance, this.confidentialERC20, this.confidentialERC20Address),
+    ).to.be.eq(BigInt(amount));
+  });
+});

test/finance/ConfidentialVestingWalletCliff.fixture.ts

@@ -0,0 +1,20 @@
+import { Signer } from "ethers";
+import { ethers } from "hardhat";
+
+import type { TestConfidentialVestingWalletCliff } from "../../types";
+
+export async function deployConfidentialVestingWalletCliffFixture(
+  account: Signer,
+  beneficiaryAddress: string,
+  token: string,
+  startTimestamp: bigint,
+  duration: bigint,
+  cliffSeconds: bigint,
+): Promise<TestConfidentialVestingWalletCliff> {
+  const contractFactory = await ethers.getContractFactory("TestConfidentialVestingWalletCliff");
+  const contract = await contractFactory
+    .connect(account)
+    .deploy(beneficiaryAddress, token, startTimestamp, duration, cliffSeconds);
+  await contract.waitForDeployment();
+  return contract;
+}