Stub out zk proof verification in marketplace tests

contracts/TestVerifier.sol

@@ -4,12 +4,22 @@ pragma solidity ^0.8.8;
 import "./Verifier.sol";
 
 contract TestVerifier is IVerifier {
+  bool private _proofsAreValid;
+
+  constructor() {
+    _proofsAreValid = true;
+  }
+
+  function setProofsAreValid(bool proofsAreValid) public {
+    _proofsAreValid = proofsAreValid;
+  }
+
   function verifyProof(
     uint[2] calldata,
     uint[2][2] calldata,
     uint[2] calldata,
     uint[3] calldata
-  ) external pure returns (bool) {
-    return false;
+  ) external view returns (bool) {
+    return _proofsAreValid;
   }
 }

test/Marketplace.test.js

@@ -215,9 +215,9 @@ describe("Marketplace", function () {
     })
 
     it("is rejected when proof is incorrect", async function () {
-      let invalid = hexlify([])
+      await verifier.setProofsAreValid(false)
       await expect(
-        marketplace.fillSlot(slot.request, slot.index, invalid)
+        marketplace.fillSlot(slot.request, slot.index, proof)
       ).to.be.revertedWith("Invalid proof")
     })