From 1ed48db34bea070e3ad2db14c6035c4025587696 Mon Sep 17 00:00:00 2001
From: James Duncombe <james.duncombe@consilienceventures.com>
Date: Mon, 19 Feb 2024 17:48:56 +0000
Subject: [PATCH] Adds a check for overfunding.

---
 contracts/fast/Crowdfund.sol | 4 ++++
 test/fast/Crowdfund.test.ts  | 5 +++++
 2 files changed, 9 insertions(+)

diff --git a/contracts/fast/Crowdfund.sol b/contracts/fast/Crowdfund.sol
index 5960b063..2aaca558 100644
--- a/contracts/fast/Crowdfund.sol
+++ b/contracts/fast/Crowdfund.sol
@@ -26,6 +26,8 @@ contract Crowdfund {
   error TokenContractError();
   /// @notice Happens when there are insufficient funds somewhere.
   error InsufficientFunds(uint256 amount);
+  /// @notice Happens when overfunding occurs.
+  error CapExceeded();
 
   /// @notice Happens when an address is not an issuer member.
   error RequiresIssuerMemberCaller();
@@ -148,6 +150,8 @@ contract Crowdfund {
   function pledge(uint256 amount) public onlyDuring(Phase.Funding) onlyFastMember {
     // Make sure the amount is non-zero.
     if (amount == 0) revert InconsistentParameter("amount");
+    // Make sure this will not result in overfunding.
+    if (isCapped() && collected + amount > params.cap) revert CapExceeded();
     // Make sure that the message sender gave us allowance for at least this amount.
     uint256 allowance = params.token.allowance(msg.sender, address(this));
     if (allowance < amount) revert InsufficientFunds(amount - allowance);
diff --git a/test/fast/Crowdfund.test.ts b/test/fast/Crowdfund.test.ts
index 497cc856..af482540 100644
--- a/test/fast/Crowdfund.test.ts
+++ b/test/fast/Crowdfund.test.ts
@@ -359,6 +359,11 @@ describe("Crowdfunds", () => {
         await expect(subject).to.have.revertedWith("InconsistentParameter");
       });
 
+      it("requires that the pledged amount + collected amount does not go over the cap", async () => {
+        const subject = crowdfund.connect(alice).pledge(32_000_000_001);
+        await expect(subject).to.have.revertedWith("CapExceeded");
+      });
+
       it("checks the allowance of the crowdfunding contract with the ERC20 contract", async () => {
         erc20.allowance.returns(100_000);
         erc20.transferFrom.returns(true);