[VRF-592] Add LINK token check (#10422)

* [VRF-592] Add LINK token check

* Add tests

* Update snapshot

* Add gethwrappers

contracts/gas-snapshots/vrf.gas-snapshot

@@ -1,16 +1,18 @@
 TrustedBlockhashStoreTest:testGenericBHSFunctions() (gas: 53507)
 TrustedBlockhashStoreTest:testTrustedBHSFunctions() (gas: 49536)
 VRFCoordinatorV2Plus_Migration:testDeregister() (gas: 101083)
-VRFCoordinatorV2Plus_Migration:testMigrateRevertsWhenInvalidCaller() (gas: 29377)
-VRFCoordinatorV2Plus_Migration:testMigrateRevertsWhenInvalidCoordinator() (gas: 19877)
-VRFCoordinatorV2Plus_Migration:testMigrateRevertsWhenPendingFulfillment() (gas: 237679)
-VRFCoordinatorV2Plus_Migration:testMigrateRevertsWhenReentrant() (gas: 361358)
-VRFCoordinatorV2Plus_Migration:testMigration() (gas: 471429)
-VRFV2Plus:testCreateSubscription() (gas: 181121)
-VRFV2Plus:testGetActiveSubscriptionIds() (gas: 3465607)
-VRFV2Plus:testRegisterProvingKey() (gas: 101019)
-VRFV2Plus:testRequestAndFulfillRandomWordsLINK() (gas: 755125)
-VRFV2Plus:testRequestAndFulfillRandomWordsNative() (gas: 705549)
-VRFV2Plus:testSetConfig() (gas: 73057)
+VRFCoordinatorV2Plus_Migration:testMigrateRevertsWhenInvalidCaller() (gas: 29421)
+VRFCoordinatorV2Plus_Migration:testMigrateRevertsWhenInvalidCoordinator() (gas: 19855)
+VRFCoordinatorV2Plus_Migration:testMigrateRevertsWhenPendingFulfillment() (gas: 237702)
+VRFCoordinatorV2Plus_Migration:testMigrateRevertsWhenReentrant() (gas: 354749)
+VRFCoordinatorV2Plus_Migration:testMigration() (gas: 471631)
+VRFCoordinatorV2Plus_Migration:testMigrationNoLink() (gas: 431052)
+VRFV2Plus:testCancelSubWithNoLink() (gas: 160261)
+VRFV2Plus:testCreateSubscription() (gas: 181127)
+VRFV2Plus:testGetActiveSubscriptionIds() (gas: 3453659)
+VRFV2Plus:testRegisterProvingKey() (gas: 101025)
+VRFV2Plus:testRequestAndFulfillRandomWordsLINK() (gas: 755178)
+VRFV2Plus:testRequestAndFulfillRandomWordsNative() (gas: 705581)
+VRFV2Plus:testSetConfig() (gas: 73032)
 VRFV2PlusWrapperTest:testRequestAndFulfillRandomWordsLINKWrapper() (gas: 390063)
 VRFV2PlusWrapperTest:testRequestAndFulfillRandomWordsNativeWrapper() (gas: 290612)

contracts/src/v0.8/dev/vrf/SubscriptionAPI.sol

@@ -400,9 +400,14 @@ abstract contract SubscriptionAPI is ConfirmedOwner, IERC677Receiver, IVRFSubscr
 
   function cancelSubscriptionHelper(uint256 subId, address to) internal {
     (uint96 balance, uint96 ethBalance) = deleteSubscription(subId);
-    if (!LINK.transfer(to, uint256(balance))) {
-      revert InsufficientBalance();
+
+    // Only withdraw LINK if the token is active and there is a balance.
+    if (address(LINK) != address(0) && balance != 0) {
+      if (!LINK.transfer(to, uint256(balance))) {
+        revert InsufficientBalance();
+      }
     }
+
     // send eth to the "to" address using call
     (bool success, ) = to.call{value: uint256(ethBalance)}("");
     if (!success) {

contracts/src/v0.8/dev/vrf/VRFCoordinatorV2Plus.sol

@@ -672,7 +672,11 @@ contract VRFCoordinatorV2Plus is VRF, SubscriptionAPI {
     bytes memory encodedData = abi.encode(migrationData);
     deleteSubscription(subId);
     IVRFCoordinatorV2PlusMigration(newCoordinator).onMigration{value: ethBalance}(encodedData);
-    require(LINK.transfer(address(newCoordinator), balance), "insufficient funds");
+
+    // Only transfer LINK if the token is active and there is a balance.
+    if (address(LINK) != address(0) && balance != 0) {
+      require(LINK.transfer(address(newCoordinator), balance), "insufficient funds");
+    }
 
     // despite the fact that we follow best practices this is still probably safest
     // to prevent any re-entrancy possibilities.

contracts/test/v0.8/foundry/vrf/VRFCoordinatorV2Plus_Migration.t.sol

@@ -26,13 +26,19 @@ contract VRFCoordinatorV2Plus_Migration is BaseTest {
 
   ExposedVRFCoordinatorV2Plus v1Coordinator;
   VRFCoordinatorV2Plus_V2Example v2Coordinator;
+  ExposedVRFCoordinatorV2Plus v1Coordinator_noLink;
+  VRFCoordinatorV2Plus_V2Example v2Coordinator_noLink;
   uint256 subId;
+  uint256 subId_noLink;
   VRFV2PlusConsumerExample testConsumer;
+  VRFV2PlusConsumerExample testConsumer_noLink;
   MockLinkToken linkToken;
   address linkTokenAddr;
   MockV3Aggregator linkEthFeed;
   address v1CoordinatorAddr;
   address v2CoordinatorAddr;
+  address v1CoordinatorAddr_noLink;
+  address v2CoordinatorAddr_noLink;
 
   event CoordinatorRegistered(address coordinatorAddress);
   event CoordinatorDeregistered(address coordinatorAddress);
@@ -43,14 +49,19 @@ contract VRFCoordinatorV2Plus_Migration is BaseTest {
     vm.deal(OWNER, 100 ether);
     address bhs = makeAddr("bhs");
     v1Coordinator = new ExposedVRFCoordinatorV2Plus(bhs);
+    v1Coordinator_noLink = new ExposedVRFCoordinatorV2Plus(bhs);
     subId = v1Coordinator.createSubscription();
+    subId_noLink = v1Coordinator_noLink.createSubscription();
     linkToken = new MockLinkToken();
     linkEthFeed = new MockV3Aggregator(18, 500000000000000000); // .5 ETH (good for testing)
     v1Coordinator.setLINKAndLINKETHFeed(address(linkToken), address(linkEthFeed));
     linkTokenAddr = address(linkToken);
     v2Coordinator = new VRFCoordinatorV2Plus_V2Example(address(linkToken), address(v1Coordinator));
+    v2Coordinator_noLink = new VRFCoordinatorV2Plus_V2Example(address(0), address(v1Coordinator_noLink));
     v1CoordinatorAddr = address(v1Coordinator);
     v2CoordinatorAddr = address(v2Coordinator);
+    v1CoordinatorAddr_noLink = address(v1Coordinator_noLink);
+    v2CoordinatorAddr_noLink = address(v2Coordinator_noLink);
 
     vm.expectEmit(
       false, // no first indexed topic
@@ -62,7 +73,18 @@ contract VRFCoordinatorV2Plus_Migration is BaseTest {
     v1Coordinator.registerMigratableCoordinator(v2CoordinatorAddr);
     assertTrue(v1Coordinator.isTargetRegisteredExternal(v2CoordinatorAddr));
 
+    vm.expectEmit(
+      false, // no first indexed topic
+      false, // no second indexed topic
+      false, // no third indexed topic
+      true // check data (target coordinator address)
+    );
+    emit CoordinatorRegistered(v2CoordinatorAddr_noLink);
+    v1Coordinator_noLink.registerMigratableCoordinator(v2CoordinatorAddr_noLink);
+    assertTrue(v1Coordinator_noLink.isTargetRegisteredExternal(v2CoordinatorAddr_noLink));
+
     testConsumer = new VRFV2PlusConsumerExample(address(v1Coordinator), address(linkToken));
+    testConsumer_noLink = new VRFV2PlusConsumerExample(address(v1Coordinator_noLink), address(0));
     v1Coordinator.setConfig(
       DEFAULT_REQUEST_CONFIRMATIONS,
       DEFAULT_CALLBACK_GAS_LIMIT,
@@ -71,8 +93,17 @@ contract VRFCoordinatorV2Plus_Migration is BaseTest {
       20_000,
       VRFCoordinatorV2Plus.FeeConfig({fulfillmentFlatFeeLinkPPM: 200, fulfillmentFlatFeeEthPPM: 100})
     );
+    v1Coordinator_noLink.setConfig(
+      DEFAULT_REQUEST_CONFIRMATIONS,
+      DEFAULT_CALLBACK_GAS_LIMIT,
+      600,
+      10_000,
+      20_000,
+      VRFCoordinatorV2Plus.FeeConfig({fulfillmentFlatFeeLinkPPM: 200, fulfillmentFlatFeeEthPPM: 100})
+    );
     registerProvingKey();
     testConsumer.setCoordinator(v1CoordinatorAddr);
+    testConsumer_noLink.setCoordinator(v1CoordinatorAddr_noLink);
   }
 
   function testDeregister() public {
@@ -181,6 +212,78 @@ contract VRFCoordinatorV2Plus_Migration is BaseTest {
     );
   }
 
+  function testMigrationNoLink() public {
+    v1Coordinator_noLink.fundSubscriptionWithEth{value: DEFAULT_NATIVE_FUNDING}(subId_noLink);
+    v1Coordinator_noLink.addConsumer(subId_noLink, address(testConsumer_noLink));
+
+    // subscription exists in V1 coordinator before migration
+    (
+      uint96 balance,
+      uint96 ethBalance,
+      uint64 reqCount,
+      address owner,
+      address[] memory consumers
+    ) = v1Coordinator_noLink.getSubscription(subId_noLink);
+    assertEq(balance, 0);
+    assertEq(ethBalance, DEFAULT_NATIVE_FUNDING);
+    assertEq(owner, address(OWNER));
+    assertEq(consumers.length, 1);
+    assertEq(consumers[0], address(testConsumer_noLink));
+
+    assertEq(v1Coordinator_noLink.s_totalBalance(), 0);
+    assertEq(v1Coordinator_noLink.s_totalEthBalance(), DEFAULT_NATIVE_FUNDING);
+
+    // Update consumer to point to the new coordinator
+    vm.expectEmit(
+      false, // no first indexed field
+      false, // no second indexed field
+      false, // no third indexed field
+      true // check data fields
+    );
+    emit MigrationCompleted(v2CoordinatorAddr_noLink, subId_noLink);
+    v1Coordinator_noLink.migrate(subId_noLink, v2CoordinatorAddr_noLink);
+
+    // subscription no longer exists in v1 coordinator after migration
+    vm.expectRevert(SubscriptionAPI.InvalidSubscription.selector);
+    v1Coordinator_noLink.getSubscription(subId);
+    assertEq(v1Coordinator_noLink.s_totalBalance(), 0);
+    assertEq(v1Coordinator_noLink.s_totalEthBalance(), 0);
+    assertEq(linkToken.balanceOf(v1CoordinatorAddr_noLink), 0);
+    assertEq(v1CoordinatorAddr_noLink.balance, 0);
+
+    // subscription exists in v2 coordinator
+    (owner, consumers, balance, ethBalance) = v2Coordinator_noLink.getSubscription(subId_noLink);
+    assertEq(owner, address(OWNER));
+    assertEq(consumers.length, 1);
+    assertEq(consumers[0], address(testConsumer_noLink));
+    assertEq(balance, 0);
+    assertEq(ethBalance, DEFAULT_NATIVE_FUNDING);
+    assertEq(v2Coordinator_noLink.s_totalLinkBalance(), 0);
+    assertEq(v2Coordinator_noLink.s_totalNativeBalance(), DEFAULT_NATIVE_FUNDING);
+    assertEq(linkToken.balanceOf(v2CoordinatorAddr_noLink), 0);
+    assertEq(v2CoordinatorAddr_noLink.balance, DEFAULT_NATIVE_FUNDING);
+
+    // calling migrate again on V1 coordinator should fail
+    vm.expectRevert(SubscriptionAPI.InvalidSubscription.selector);
+    v1Coordinator_noLink.migrate(subId_noLink, v2CoordinatorAddr_noLink);
+
+    // test request still works after migration
+    testConsumer_noLink.requestRandomWords(
+      DEFAULT_CALLBACK_GAS_LIMIT,
+      DEFAULT_REQUEST_CONFIRMATIONS,
+      DEFAULT_NUM_WORDS,
+      KEY_HASH,
+      false
+    );
+    assertEq(testConsumer_noLink.s_recentRequestId(), 1);
+
+    v2Coordinator_noLink.fulfillRandomWords(testConsumer_noLink.s_recentRequestId());
+    assertEq(
+      testConsumer_noLink.getRandomness(testConsumer_noLink.s_recentRequestId(), 0),
+      v2Coordinator_noLink.generateFakeRandomness(testConsumer_noLink.s_recentRequestId())[0]
+    );
+  }
+
   function testMigrateRevertsWhenInvalidCoordinator() external {
     address invalidCoordinator = makeAddr("invalidCoordinator");
 
@@ -227,6 +330,7 @@ contract VRFCoordinatorV2Plus_Migration is BaseTest {
   function registerProvingKey() public {
     uint256[2] memory uncompressedKeyParts = this.getProvingKeyParts(UNCOMPRESSED_PUBLIC_KEY);
     v1Coordinator.registerProvingKey(OWNER, uncompressedKeyParts);
+    v1Coordinator_noLink.registerProvingKey(OWNER, uncompressedKeyParts);
   }
 
   // note: Call this function via this.getProvingKeyParts to be able to pass memory as calldata and

contracts/test/v0.8/foundry/vrf/VRFV2Plus.t.sol

@@ -6,6 +6,7 @@ import {MockLinkToken} from "../../../../src/v0.8/mocks/MockLinkToken.sol";
 import {MockV3Aggregator} from "../../../../src/v0.8/tests/MockV3Aggregator.sol";
 import {ExposedVRFCoordinatorV2Plus} from "../../../../src/v0.8/dev/vrf/testhelpers/ExposedVRFCoordinatorV2Plus.sol";
 import {VRFCoordinatorV2Plus} from "../../../../src/v0.8/dev/vrf/VRFCoordinatorV2Plus.sol";
+import {SubscriptionAPI} from "../../../../src/v0.8/dev/vrf/SubscriptionAPI.sol";
 import {BlockhashStore} from "../../../../src/v0.8/dev/BlockhashStore.sol";
 import {VRFV2PlusConsumerExample} from "../../../../src/v0.8/dev/vrf/testhelpers/VRFV2PlusConsumerExample.sol";
 import {VRFV2PlusClient} from "../../../../src/v0.8/dev/vrf/libraries/VRFV2PlusClient.sol";
@@ -31,6 +32,7 @@ contract VRFV2Plus is BaseTest {
 
   BlockhashStore s_bhs;
   ExposedVRFCoordinatorV2Plus s_testCoordinator;
+  ExposedVRFCoordinatorV2Plus s_testCoordinator_noLink;
   VRFV2PlusConsumerExample s_testConsumer;
   MockLinkToken s_linkToken;
   MockV3Aggregator s_linkEthFeed;
@@ -57,9 +59,8 @@ contract VRFV2Plus is BaseTest {
     s_bhs = new BlockhashStore();
 
     // Deploy coordinator and consumer.
+    // Note: adding contract deployments to this section will require the VRF proofs be regenerated.
     s_testCoordinator = new ExposedVRFCoordinatorV2Plus(address(s_bhs));
-
-    // Deploy link token and link/eth feed.
     s_linkToken = new MockLinkToken();
     s_linkEthFeed = new MockV3Aggregator(18, 500000000000000000); // .5 ETH (good for testing)
 
@@ -81,6 +82,8 @@ contract VRFV2Plus is BaseTest {
     }
     s_testConsumer = VRFV2PlusConsumerExample(consumerCreate2Address);
 
+    s_testCoordinator_noLink = new ExposedVRFCoordinatorV2Plus(address(s_bhs));
+
     // Configure the coordinator.
     s_testCoordinator.setLINKAndLINKETHFeed(address(s_linkToken), address(s_linkEthFeed));
   }
@@ -142,6 +145,18 @@ contract VRFV2Plus is BaseTest {
     s_testCoordinator.fundSubscriptionWithEth{value: 10 ether}(subId);
   }
 
+  function testCancelSubWithNoLink() public {
+    uint256 subId = s_testCoordinator_noLink.createSubscription();
+    s_testCoordinator_noLink.fundSubscriptionWithEth{value: 1000 ether}(subId);
+
+    assertEq(LINK_WHALE.balance, 9000 ether);
+    s_testCoordinator_noLink.cancelSubscription(subId, LINK_WHALE);
+    assertEq(LINK_WHALE.balance, 10_000 ether);
+
+    vm.expectRevert(SubscriptionAPI.InvalidSubscription.selector);
+    s_testCoordinator_noLink.getSubscription(subId);
+  }
+
   function testGetActiveSubscriptionIds() public {
     uint numSubs = 40;
     for (uint i = 0; i < numSubs; i++) {

core/gethwrappers/generation/generated-wrapper-dependency-versions-do-not-edit.txt

@@ -75,7 +75,7 @@ vrf_consumer_v2_upgradeable_example: ../../contracts/solc/v0.8.6/VRFConsumerV2Up
 vrf_coordinator_mock: ../../contracts/solc/v0.8.6/VRFCoordinatorMock.abi ../../contracts/solc/v0.8.6/VRFCoordinatorMock.bin 5c495cf8df1f46d8736b9150cdf174cce358cb8352f60f0d5bb9581e23920501
 vrf_coordinator_v2: ../../contracts/solc/v0.8.6/VRFCoordinatorV2.abi ../../contracts/solc/v0.8.6/VRFCoordinatorV2.bin 75c87cf1624a401ac6303df9c8e04896aa8a53849e8b0c3d7340a9d089ef6d4b
 vrf_coordinator_v2_plus_v2_example: ../../contracts/solc/v0.8.6/VRFCoordinatorV2Plus_V2Example.abi ../../contracts/solc/v0.8.6/VRFCoordinatorV2Plus_V2Example.bin 50d881ecf2551c0e56b84cb932f068b703b38b00c73eb05d4e4b80754ecf6b6d
-vrf_coordinator_v2plus: ../../contracts/solc/v0.8.6/VRFCoordinatorV2Plus.abi ../../contracts/solc/v0.8.6/VRFCoordinatorV2Plus.bin 03bcd9234a008f13fb9b0bc8bb28d80b93c294092769e4cebb3c8c8ba5f56950
+vrf_coordinator_v2plus: ../../contracts/solc/v0.8.6/VRFCoordinatorV2Plus.abi ../../contracts/solc/v0.8.6/VRFCoordinatorV2Plus.bin bcd16361198eea25b9ca2fb41f019d0ff02f4e7b05289608c37f2e4c9440754d
 vrf_external_sub_owner_example: ../../contracts/solc/v0.8.6/VRFExternalSubOwnerExample.abi ../../contracts/solc/v0.8.6/VRFExternalSubOwnerExample.bin 14f888eb313930b50233a6f01ea31eba0206b7f41a41f6311670da8bb8a26963
 vrf_load_test_external_sub_owner: ../../contracts/solc/v0.8.6/VRFLoadTestExternalSubOwner.abi ../../contracts/solc/v0.8.6/VRFLoadTestExternalSubOwner.bin 2097faa70265e420036cc8a3efb1f1e0836ad2d7323b295b9a26a125dbbe6c7d
 vrf_load_test_ownerless_consumer: ../../contracts/solc/v0.8.6/VRFLoadTestOwnerlessConsumer.abi ../../contracts/solc/v0.8.6/VRFLoadTestOwnerlessConsumer.bin 74f914843cbc70b9c3079c3e1c709382ce415225e8bb40113e7ac018bfcb0f5c