fix(FLOW-7): Enforce sentinel hygiene for NO_YIELDVAULT_ID

FLOW_YIELD_VAULTS_EVM_BRIDGE_DESIGN.md

@@ -195,7 +195,7 @@ struct Request {
     RequestStatus status;        // PENDING | PROCESSING | COMPLETED | FAILED
     address tokenAddress;        // NATIVE_FLOW (0xFFfF...FfFFFfF) or ERC20 address
     uint256 amount;              // Amount in wei (0 for CLOSE_YIELDVAULT)
-    uint64 yieldVaultId;               // Target YieldVault Id (0 for CREATE_YIELDVAULT until completed; NO_YIELDVAULT_ID on failed CREATE during processing; cancel/drop keep 0)
+    uint64 yieldVaultId;          // Target YieldVault Id (NO_YIELDVAULT_ID for CREATE_YIELDVAULT until completed; for others set at request creation)
     uint256 timestamp;           // Block timestamp when created
     string message;              // Status message or error reason
     string vaultIdentifier;      // Cadence vault type (e.g., "A.xxx.FlowToken.Vault")

FRONTEND_INTEGRATION.md

@@ -607,9 +607,9 @@ if (wallet.type === "evm") {
 // Sentinel address for native FLOW token
 const NATIVE_FLOW = "0xFFfFfFffFFfffFFfFFfFFFFFffFFFffffFfFFFfF";
 
-// Sentinel value for "no YieldVault" (Cadence may return this on failed CREATE)
+// Sentinel value for "no YieldVault" (also used as placeholder for CREATE until processed)
 const NO_YIELDVAULT_ID = 18446744073709551615n; // type(uint64).max
-// CREATE requests start with yieldVaultId = 0 until processed
+// CREATE requests start with yieldVaultId = NO_YIELDVAULT_ID until processed
 
 // Request Types
 enum RequestType {

cadence/tests/error_handling_test.cdc

@@ -58,7 +58,7 @@ fun testInvalidRequestType() {
             status: FlowYieldVaultsEVM.RequestStatus.PENDING.rawValue,
             tokenAddress: nativeFlowAddr,
             amount: 1000000000000000000,
-            yieldVaultId: 0,
+            yieldVaultId: FlowYieldVaultsEVM.noYieldVaultId,
             timestamp: 0,
             message: "",
             vaultIdentifier: mockVaultIdentifier,

cadence/tests/evm_bridge_lifecycle_test.cdc

@@ -50,7 +50,7 @@ fun testCreateYieldVaultFromEVMRequest() {
         status: FlowYieldVaultsEVM.RequestStatus.PENDING.rawValue,
         tokenAddress: nativeFlowAddr,
         amount: 1000000000000000000, // 1 FLOW in wei (10^18)
-        yieldVaultId: 0, // Not used for CREATE
+        yieldVaultId: FlowYieldVaultsEVM.noYieldVaultId, // Placeholder until Cadence assigns a real ID
         timestamp: 0,
         message: "",
         vaultIdentifier: mockVaultIdentifier,
@@ -161,7 +161,7 @@ fun testRequestStatusTransitions() {
         status: FlowYieldVaultsEVM.RequestStatus.COMPLETED.rawValue,
         tokenAddress: nativeFlowAddr,
         amount: 1000000000000000000,
-        yieldVaultId: 0,
+        yieldVaultId: FlowYieldVaultsEVM.noYieldVaultId,
         timestamp: 0,
         message: "",
         vaultIdentifier: mockVaultIdentifier,
@@ -177,7 +177,7 @@ fun testRequestStatusTransitions() {
         status: FlowYieldVaultsEVM.RequestStatus.FAILED.rawValue,
         tokenAddress: nativeFlowAddr,
         amount: 1000000000000000000,
-        yieldVaultId: 0,
+        yieldVaultId: FlowYieldVaultsEVM.noYieldVaultId,
         timestamp: 0,
         message: "Insufficient balance",
         vaultIdentifier: mockVaultIdentifier,
@@ -197,7 +197,7 @@ fun testMultipleUsersIndependentYieldVaults() {
         status: FlowYieldVaultsEVM.RequestStatus.PENDING.rawValue,
         tokenAddress: nativeFlowAddr,
         amount: 1000000000000000000,
-        yieldVaultId: 0,
+        yieldVaultId: FlowYieldVaultsEVM.noYieldVaultId,
         timestamp: 0,
         message: "",
         vaultIdentifier: mockVaultIdentifier,
@@ -211,7 +211,7 @@ fun testMultipleUsersIndependentYieldVaults() {
         status: FlowYieldVaultsEVM.RequestStatus.PENDING.rawValue,
         tokenAddress: nativeFlowAddr,
         amount: 2000000000000000000,
-        yieldVaultId: 0,
+        yieldVaultId: FlowYieldVaultsEVM.noYieldVaultId,
         timestamp: 0,
         message: "",
         vaultIdentifier: mockVaultIdentifier,
@@ -268,7 +268,7 @@ fun testVaultAndStrategyIdentifiers() {
         status: FlowYieldVaultsEVM.RequestStatus.PENDING.rawValue,
         tokenAddress: nativeFlowAddr,
         amount: 1000000000000000000,
-        yieldVaultId: 0,
+        yieldVaultId: FlowYieldVaultsEVM.noYieldVaultId,
         timestamp: 0,
         message: "",
         vaultIdentifier: customVaultId,

solidity/src/FlowYieldVaultsRequests.sol

@@ -61,7 +61,7 @@ contract FlowYieldVaultsRequests is ReentrancyGuard, Ownable2Step {
     /// @param status Current status of the request
     /// @param tokenAddress Token being deposited/withdrawn (NATIVE_FLOW for native $FLOW)
     /// @param amount Amount of tokens involved
-    /// @param yieldVaultId Associated YieldVault Id (0 for CREATE_YIELDVAULT until completed; NO_YIELDVAULT_ID only on failed CREATE)
+    /// @param yieldVaultId Associated YieldVault Id (NO_YIELDVAULT_ID for CREATE_YIELDVAULT until assigned by Cadence)
     /// @param timestamp Block timestamp when request was created
     /// @param message Status message or error reason
     /// @param vaultIdentifier Cadence vault type identifier for CREATE_YIELDVAULT
@@ -245,6 +245,9 @@ contract FlowYieldVaultsRequests is ReentrancyGuard, Ownable2Step {
     /// @notice YieldVault token is not set
     error YieldVaultTokenNotSet(uint64 yieldVaultId);
 
+    /// @notice Cannot register sentinel value NO_YIELDVAULT_ID as a valid YieldVault
+    error CannotRegisterSentinelYieldVaultId();
+
     /// @notice Token does not match YieldVault's configured token
     error YieldVaultTokenMismatch(
         uint64 yieldVaultId,
@@ -274,7 +277,7 @@ contract FlowYieldVaultsRequests is ReentrancyGuard, Ownable2Step {
     /// @param requestType Type of operation requested
     /// @param tokenAddress Token involved in the request
     /// @param amount Amount of tokens
-    /// @param yieldVaultId Associated YieldVault Id (0 for CREATE_YIELDVAULT until assigned by Cadence; NO_YIELDVAULT_ID only on failed CREATE)
+    /// @param yieldVaultId Associated YieldVault Id (NO_YIELDVAULT_ID for CREATE_YIELDVAULT until assigned by Cadence)
     /// @param timestamp Block timestamp when request was created
     /// @param vaultIdentifier Cadence vault type identifier (for CREATE_YIELDVAULT)
     /// @param strategyIdentifier Cadence strategy type identifier (for CREATE_YIELDVAULT)
@@ -792,7 +795,7 @@ contract FlowYieldVaultsRequests is ReentrancyGuard, Ownable2Step {
                 RequestType.CREATE_YIELDVAULT,
                 tokenAddress,
                 amount,
-                0,
+                NO_YIELDVAULT_ID,
                 vaultIdentifier,
                 strategyIdentifier
             );
@@ -1545,6 +1548,9 @@ contract FlowYieldVaultsRequests is ReentrancyGuard, Ownable2Step {
         address tokenAddress,
         uint256 requestId
     ) internal {
+        // Reject sentinel value to prevent corruption of "no yieldvault" semantics
+        if (yieldVaultId == NO_YIELDVAULT_ID) revert CannotRegisterSentinelYieldVaultId();
+
         // Mark YieldVault as valid and set owner
         validYieldVaultIds[yieldVaultId] = true;
         yieldVaultOwners[yieldVaultId] = user;
@@ -1612,7 +1618,7 @@ contract FlowYieldVaultsRequests is ReentrancyGuard, Ownable2Step {
      * @param requestType The type of request (CREATE, DEPOSIT, WITHDRAW, CLOSE).
      * @param tokenAddress The token involved in this request.
      * @param amount The amount of tokens involved (0 for CLOSE requests).
-     * @param yieldVaultId The YieldVault Id (0 for CREATE until assigned by Cadence; NO_YIELDVAULT_ID only on failed CREATE).
+     * @param yieldVaultId The YieldVault Id (NO_YIELDVAULT_ID for CREATE until assigned by Cadence).
      * @param vaultIdentifier Cadence vault type identifier (only for CREATE requests).
      * @param strategyIdentifier Cadence strategy type identifier (only for CREATE requests).
      * @return The newly created request ID.

solidity/test/FlowYieldVaultsRequests.t.sol

@@ -66,6 +66,45 @@ contract FlowYieldVaultsRequestsTest is Test {
         assertEq(req.amount, 1 ether);
     }
 
+    function test_CreateYieldVault_UsesSentinelYieldVaultIdPlaceholder() public {
+        vm.prank(user);
+        uint256 reqId = c.createYieldVault{value: 1 ether}(NATIVE_FLOW, 1 ether, VAULT_ID, STRATEGY_ID);
+
+        uint64 sentinelYieldVaultId = c.NO_YIELDVAULT_ID();
+        FlowYieldVaultsRequests.Request memory req = c.getRequest(reqId);
+        assertEq(
+            req.yieldVaultId,
+            sentinelYieldVaultId,
+            "CREATE should start with NO_YIELDVAULT_ID"
+        );
+
+        vm.startPrank(coa);
+        c.startProcessing(reqId);
+        vm.expectRevert(
+            FlowYieldVaultsRequests.CannotRegisterSentinelYieldVaultId.selector
+        );
+        c.completeProcessing(
+            reqId,
+            true,
+            sentinelYieldVaultId,
+            "Invalid yieldVaultId"
+        );
+        vm.stopPrank();
+    }
+
+    function test_CreateYieldVault_CanRegisterZeroYieldVaultId() public {
+        vm.prank(user);
+        uint256 reqId = c.createYieldVault{value: 1 ether}(NATIVE_FLOW, 1 ether, VAULT_ID, STRATEGY_ID);
+
+        vm.startPrank(coa);
+        c.startProcessing(reqId);
+        c.completeProcessing(reqId, true, 0, "YieldVault 0 created");
+        vm.stopPrank();
+
+        assertTrue(c.isYieldVaultIdValid(0), "YieldVault ID 0 should be valid");
+        assertTrue(c.doesUserOwnYieldVault(user, 0), "User should own YieldVault 0");
+    }
+
     function test_DepositToYieldVault() public {
         vm.prank(user);
         uint256 reqId = c.depositToYieldVault{value: 1 ether}(42, NATIVE_FLOW, 1 ether);
@@ -189,8 +228,9 @@ contract FlowYieldVaultsRequestsTest is Test {
         assertEq(c.getUserPendingBalance(user, NATIVE_FLOW), 0);
 
         // 3. COA fails and returns funds
+        uint64 sentinelYieldVaultId = c.NO_YIELDVAULT_ID();
         vm.prank(coa);
-        c.completeProcessing{value: 1 ether}(reqId, false, 0, "Failed");
+        c.completeProcessing{value: 1 ether}(reqId, false, sentinelYieldVaultId, "Failed");
 
         // 4. User has refund in claimableRefunds (not pendingUserBalances)
         assertEq(c.getUserPendingBalance(user, NATIVE_FLOW), 0);
@@ -222,8 +262,9 @@ contract FlowYieldVaultsRequestsTest is Test {
         // Process and fail
         vm.prank(coa);
         c.startProcessing(reqId);
+        uint64 sentinelYieldVaultId = c.NO_YIELDVAULT_ID();
         vm.prank(coa);
-        c.completeProcessing{value: 2 ether}(reqId, false, 0, "Failed");
+        c.completeProcessing{value: 2 ether}(reqId, false, sentinelYieldVaultId, "Failed");
 
         // Claim only NATIVE_FLOW
         uint256 balBefore = user.balance;
@@ -240,8 +281,9 @@ contract FlowYieldVaultsRequestsTest is Test {
 
         vm.prank(coa);
         c.startProcessing(reqId);
+        uint64 sentinelYieldVaultId = c.NO_YIELDVAULT_ID();
         vm.prank(coa);
-        c.completeProcessing{value: 1 ether}(reqId, false, 0, "Failed");
+        c.completeProcessing{value: 1 ether}(reqId, false, sentinelYieldVaultId, "Failed");
 
         // RefundClaimed is emitted on claim (no BalanceUpdated since we use separate claimableRefunds mapping)
         vm.prank(user);
@@ -321,7 +363,7 @@ contract FlowYieldVaultsRequestsTest is Test {
         assertEq(c.getClaimableRefund(user, NATIVE_FLOW), 0);
 
         // COA must return funds when completing with failure
-        c.completeProcessing{value: 1 ether}(reqId, false, 0, "Cadence error");
+        c.completeProcessing{value: 1 ether}(reqId, false, c.NO_YIELDVAULT_ID(), "Cadence error");
         vm.stopPrank();
 
         // Funds go to claimableRefunds (not pendingUserBalances)
@@ -1260,7 +1302,7 @@ contract FlowYieldVaultsRequestsTest is Test {
         vm.startPrank(coa);
         c.startProcessing(req1);
         // COA must return funds when completing with failure
-        c.completeProcessing{value: 1 ether}(req1, false, 0, "Failed");
+        c.completeProcessing{value: 1 ether}(req1, false, c.NO_YIELDVAULT_ID(), "Failed");
         vm.stopPrank();
 
         // req1 should still be removed from pending (it's marked FAILED)