From 604d4c87eb2e4faa0fd65d9c85186741d69be250 Mon Sep 17 00:00:00 2001
From: Arnaud <arnaud@status.im>
Date: Fri, 24 Jan 2025 10:13:45 +0100
Subject: [PATCH] Reject when probability is 0 (#212)

* Reject when probability is 0
* Apply custom error
---
 contracts/Proofs.sol | 4 ++++
 test/Proofs.test.js  | 7 +++++++
 2 files changed, 11 insertions(+)

diff --git a/contracts/Proofs.sol b/contracts/Proofs.sol
index d0719e0..3b9d267 100644
--- a/contracts/Proofs.sol
+++ b/contracts/Proofs.sol
@@ -19,6 +19,7 @@ abstract contract Proofs is Periods {
   error Proofs_ProofNotMissing();
   error Proofs_ProofNotRequired();
   error Proofs_ProofAlreadyMarkedMissing();
+  error Proofs_InvalidProbability();
 
   ProofConfig private _config;
   IGroth16Verifier private _verifier;
@@ -69,6 +70,9 @@ abstract contract Proofs is Periods {
    *     and saves the required probability.
    */
   function _startRequiringProofs(SlotId id, uint256 probability) internal {
+    if (probability == 0) {
+      revert Proofs_InvalidProbability();
+    }
     _slotStarts[id] = block.timestamp;
     _probabilities[id] = probability;
   }
diff --git a/test/Proofs.test.js b/test/Proofs.test.js
index 4cd5b73..1c6931b 100644
--- a/test/Proofs.test.js
+++ b/test/Proofs.test.js
@@ -299,5 +299,12 @@ describe("Proofs", function () {
       await proofs.setSlotState(slotId, SlotState.Finished)
       expect(await proofs.isProofRequired(slotId)).to.be.false
     })
+
+    it("is rejected when probability is 0", async function () {
+      const probability = 0
+      await expect(
+        proofs.startRequiringProofs(slotId, probability)
+      ).to.be.revertedWith("Proofs_InvalidProbability")
+    })
   })
 })