From 1450cd1e0dc45f6f66eda984acaa1071cd5f4728 Mon Sep 17 00:00:00 2001
From: Mitch <mitchell@aztecprotocol.com>
Date: Sun, 29 Sep 2024 16:46:47 -0400
Subject: [PATCH] compensate for balance inquiries beyond the delay window

---
 .../src/core/ProofCommitmentEscrow.sol        | 11 +++++++++-
 l1-contracts/src/core/Rollup.sol              |  2 +-
 l1-contracts/test/Rollup.t.sol                |  3 +--
 .../test/prover-coordination/EscrowERC20.sol  |  3 +--
 .../ProofCommitmentEscrow.t.sol               | 20 ++++++++++++++++---
 .../test/prover-coordination/Signatures.t.sol |  2 +-
 6 files changed, 31 insertions(+), 10 deletions(-)

diff --git a/l1-contracts/src/core/ProofCommitmentEscrow.sol b/l1-contracts/src/core/ProofCommitmentEscrow.sol
index 9bb9132ec45e..147cd2c69dba 100644
--- a/l1-contracts/src/core/ProofCommitmentEscrow.sol
+++ b/l1-contracts/src/core/ProofCommitmentEscrow.sol
@@ -1,5 +1,5 @@
 // SPDX-License-Identifier: Apache-2.0
-// Copyright 2023 Aztec Labs.
+// Copyright 2024 Aztec Labs.
 pragma solidity >=0.8.27;
 
 import {SafeERC20} from "@oz/token/ERC20/utils/SafeERC20.sol";
@@ -124,6 +124,8 @@ contract ProofCommitmentEscrow is IProofCommitmentEscrow {
   /**
    * @notice  Get the minimum balance of a prover at a given timestamp.
    *
+   * @dev     Returns 0 if the timestamp is beyond the WITHDRAW_DELAY from the current block timestamp
+   *
    * @param _timestamp The timestamp at which to check the balance
    * @param _prover The address of the prover
    *
@@ -135,6 +137,13 @@ contract ProofCommitmentEscrow is IProofCommitmentEscrow {
     override
     returns (uint256)
   {
+    // If the timestamp is beyond the WITHDRAW_DELAY, the minimum possible balance is 0;
+    // the prover could issue a withdraw request in this block for the full amount,
+    // and execute it exactly WITHDRAW_DELAY later.
+    if (_timestamp >= block.timestamp + WITHDRAW_DELAY) {
+      return 0;
+    }
+
     uint256 balance = deposits[_prover];
     if (withdrawRequests[_prover].executableAt <= _timestamp) {
       balance -= withdrawRequests[_prover].amount;
diff --git a/l1-contracts/src/core/Rollup.sol b/l1-contracts/src/core/Rollup.sol
index 930a022dcd80..b90983c872c1 100644
--- a/l1-contracts/src/core/Rollup.sol
+++ b/l1-contracts/src/core/Rollup.sol
@@ -1,5 +1,5 @@
 // SPDX-License-Identifier: Apache-2.0
-// Copyright 2023 Aztec Labs.
+// Copyright 2024 Aztec Labs.
 pragma solidity >=0.8.27;
 
 import {IProofCommitmentEscrow} from "@aztec/core/interfaces/IProofCommitmentEscrow.sol";
diff --git a/l1-contracts/test/Rollup.t.sol b/l1-contracts/test/Rollup.t.sol
index 9ecc2e07e452..a58403e5abce 100644
--- a/l1-contracts/test/Rollup.t.sol
+++ b/l1-contracts/test/Rollup.t.sol
@@ -1,9 +1,8 @@
 // SPDX-License-Identifier: Apache-2.0
-// Copyright 2023 Aztec Labs.
+// Copyright 2024 Aztec Labs.
 pragma solidity >=0.8.27;
 
 import {DecoderBase} from "./decoders/Base.sol";
-import {console} from "forge-std/console.sol";
 
 import {DataStructures} from "@aztec/core/libraries/DataStructures.sol";
 import {Constants} from "@aztec/core/libraries/ConstantsGen.sol";
diff --git a/l1-contracts/test/prover-coordination/EscrowERC20.sol b/l1-contracts/test/prover-coordination/EscrowERC20.sol
index 22085e612d89..48b743e825c0 100644
--- a/l1-contracts/test/prover-coordination/EscrowERC20.sol
+++ b/l1-contracts/test/prover-coordination/EscrowERC20.sol
@@ -1,5 +1,5 @@
 // SPDX-License-Identifier: Apache-2.0
-// docs:start:contract
+// Copyright 2024 Aztec Labs.
 pragma solidity ^0.8.27;
 
 import {ERC20} from "@oz/token/ERC20/ERC20.sol";
@@ -13,4 +13,3 @@ contract EscrowERC20 is ERC20 {
     _mint(to, amount);
   }
 }
-// docs:end:contract
diff --git a/l1-contracts/test/prover-coordination/ProofCommitmentEscrow.t.sol b/l1-contracts/test/prover-coordination/ProofCommitmentEscrow.t.sol
index 2fa835783929..aacc1f6ce4dc 100644
--- a/l1-contracts/test/prover-coordination/ProofCommitmentEscrow.t.sol
+++ b/l1-contracts/test/prover-coordination/ProofCommitmentEscrow.t.sol
@@ -1,5 +1,5 @@
 // SPDX-License-Identifier: Apache-2.0
-// Copyright 2023 Aztec Labs.
+// Copyright 2024 Aztec Labs.
 pragma solidity >=0.8.27;
 
 import {Test} from "forge-std/Test.sol";
@@ -271,7 +271,7 @@ contract TestProofCommitmentEscrow is Test {
     );
 
     assertEq(
-      _escrow.minBalanceAtTime(withdrawReadyAt, prover),
+      _escrow.minBalanceAtTime(withdrawReadyAt - 1, prover),
       depositAmount,
       "Min balance should match deposit amount before withdraw request matures"
     );
@@ -285,10 +285,24 @@ contract TestProofCommitmentEscrow is Test {
       "Min balance should be unaffected by pending withdraw request before maturity"
     );
 
+    assertEq(
+      _escrow.minBalanceAtTime(block.timestamp + _escrow.WITHDRAW_DELAY(), prover),
+      0,
+      "Min balance should be 0 at or beyond the delay window"
+    );
+
+    vm.warp(block.timestamp + 1);
+
     assertEq(
       _escrow.minBalanceAtTime(withdrawReadyAt, prover),
       depositAmount - withdrawAmount,
-      "Min balance should reflect pending withdraw request after maturity"
+      "Min balance should be 75 after withdraw request matures"
+    );
+
+    assertEq(
+      _escrow.minBalanceAtTime(withdrawReadyAt + 1, prover),
+      0,
+      "Min balance should be 0 at or beyond the delay window"
     );
   }
 
diff --git a/l1-contracts/test/prover-coordination/Signatures.t.sol b/l1-contracts/test/prover-coordination/Signatures.t.sol
index 9c946e5b9f5f..1b3fd1fbbb68 100644
--- a/l1-contracts/test/prover-coordination/Signatures.t.sol
+++ b/l1-contracts/test/prover-coordination/Signatures.t.sol
@@ -1,5 +1,5 @@
 // SPDX-License-Identifier: Apache-2.0
-// Copyright 2023 Aztec Labs.
+// Copyright 2024 Aztec Labs.
 pragma solidity >=0.8.27;
 
 import {Test} from "forge-std/Test.sol";