marketplace: remove 'Paid' state

This state is no longer necessary, vault ensures
that payouts happen only once. Hosts could bypass
this state anyway by withdrawing from the vault
directly.

contracts/Marketplace.sol

@@ -30,7 +30,6 @@ contract Marketplace is SlotReservations, Proofs, StateRetrieval, Endian {
   error Marketplace_InvalidCid();
   error Marketplace_SlotNotFree();
   error Marketplace_InvalidSlotHost();
-  error Marketplace_AlreadyPaid();
   error Marketplace_UnknownRequest();
   error Marketplace_InvalidState();
   error Marketplace_StartNotBeforeExpiry();
@@ -257,8 +256,6 @@ contract Marketplace is SlotReservations, Proofs, StateRetrieval, Endian {
     if (slot.host != msg.sender) revert Marketplace_InvalidSlotHost();
 
     SlotState state = slotState(slotId);
-    if (state == SlotState.Paid) revert Marketplace_AlreadyPaid();
-
     if (state == SlotState.Finished) {
       _payoutSlot(slot.requestId, slotId);
     } else if (state == SlotState.Cancelled) {
@@ -394,7 +391,6 @@ contract Marketplace is SlotReservations, Proofs, StateRetrieval, Endian {
     _removeFromMyRequests(request.client, requestId);
     _removeFromMySlots(slot.host, slotId);
 
-    slot.state = SlotState.Paid;
     FundId fund = requestId.asFundId();
     AccountId account = _vault.hostAccount(slot.host, slot.slotIndex);
     _vault.withdraw(fund, account);
@@ -413,7 +409,6 @@ contract Marketplace is SlotReservations, Proofs, StateRetrieval, Endian {
   ) private requestIsKnown(requestId) {
     Slot storage slot = _slots[slotId];
     _removeFromMySlots(slot.host, slotId);
-    slot.state = SlotState.Paid;
     FundId fund = requestId.asFundId();
     AccountId account = _vault.hostAccount(slot.host, slot.slotIndex);
     _vault.withdraw(fund, account);
@@ -525,9 +520,6 @@ contract Marketplace is SlotReservations, Proofs, StateRetrieval, Endian {
       return SlotState.Free;
     }
     RequestState reqState = requestState(slot.requestId);
-    if (slot.state == SlotState.Paid) {
-      return SlotState.Paid;
-    }
     if (reqState == RequestState.Cancelled) {
       return SlotState.Cancelled;
     }

contracts/Requests.sol

@@ -43,7 +43,6 @@ enum SlotState {
   Filled, // host has filled slot
   Finished, // successfully completed
   Failed, // the request has failed
-  Paid, // host has been paid
   Cancelled, // when request was cancelled then slot is cancelled as well
   Repair // when slot slot was forcible freed (host was kicked out from hosting the slot because of too many missed proofs) and needs to be repaired
 }

test/Marketplace.test.js

@@ -669,13 +669,14 @@ describe("Marketplace", function () {
       expect(endBalance).to.equal(startBalance)
     })
 
-    it("can only be done once", async function () {
+    it("pays only once", async function () {
       await waitUntilStarted(marketplace, request, proof, token)
       await waitUntilFinished(marketplace, requestId(request))
       await marketplace.freeSlot(slotId(slot))
-      await expect(marketplace.freeSlot(slotId(slot))).to.be.revertedWith(
-        "Marketplace_AlreadyPaid"
-      )
+      const startBalance = await token.balanceOf(host.address)
+      await marketplace.freeSlot(slotId(slot))
+      const endBalance = await token.balanceOf(host.address)
+      expect(endBalance).to.equal(startBalance)
     })
 
     it("cannot be filled again", async function () {
@@ -968,8 +969,7 @@ describe("Marketplace", function () {
   })
 
   describe("slot state", function () {
-    const { Free, Filled, Finished, Failed, Paid, Cancelled, Repair } =
-      SlotState
+    const { Free, Filled, Finished, Failed, Cancelled, Repair } = SlotState
     let period, periodEnd
 
     beforeEach(async function () {
@@ -1042,13 +1042,6 @@ describe("Marketplace", function () {
       await waitUntilSlotFailed(marketplace, request, slot)
       expect(await marketplace.slotState(slotId(slot))).to.equal(Failed)
     })
-
-    it("changes to 'Paid' when host has been paid", async function () {
-      await waitUntilStarted(marketplace, request, proof, token)
-      await waitUntilFinished(marketplace, slot.request)
-      await marketplace.freeSlot(slotId(slot))
-      expect(await marketplace.slotState(slotId(slot))).to.equal(Paid)
-    })
   })
 
   describe("slot probability", function () {

test/requests.js

@@ -13,9 +13,8 @@ const SlotState = {
   Filled: 1,
   Finished: 2,
   Failed: 3,
-  Paid: 4,
-  Cancelled: 5,
-  Repair: 6,
+  Cancelled: 4,
+  Repair: 5,
 }
 
 function enableRequestAssertions() {