VRFv2 feedback #2 (#5175)

* V3 listener working with integration test

* Testing offchain sim

* Address misc audit feedback

* Cleanup

* Lints, fix MaliciousConsumer test and add a reserved link test

* Fmt and fix linter after rebasing

* Contract lint

* Little more time for tx fulfillment

* Some comments about gasAfterPaymentCalc

* Address go feedback

* Add tiered fees

* More tiers

* Remove unused event and include fallback linketh price in public config

* Bump timeouts on FM tests and remove redundant app stop

* Fix FM tests, remove unused import

* One more

Co-authored-by: autorebase-bot <92488320+autorebase-bot@users.noreply.github.com>
Co-authored-by: Jordan Krage <jmank88@gmail.com>

contracts/src/v0.8/interfaces/VRFCoordinatorV2Interface.sol

@@ -2,34 +2,6 @@
 pragma solidity ^0.8.0;
 
 interface VRFCoordinatorV2Interface {
-  /**
-   * @notice Returns the global config that applies to all VRF requests.
-   * @return minimumRequestBlockConfirmations - A minimum number of confirmation
-   * blocks on VRF requests before oracles should respond.
-   * @return fulfillmentFlatFeeLinkPPM - The charge per request on top of the gas fees.
-   * Its flat fee specified in millionths of LINK.
-   * @return maxGasLimit - The maximum gas limit supported for a fulfillRandomWords callback.
-   * @return stalenessSeconds - How long we wait until we consider the ETH/LINK price
-   * (used for converting gas costs to LINK) is stale and use `fallbackWeiPerUnitLink`
-   * @return gasAfterPaymentCalculation - How much gas is used outside of the payment calculation,
-   * i.e. the gas overhead of actually making the payment to oracles.
-   * @return minimumSubscriptionBalance - The minimum subscription balance required to make a request. Its set to be about 300%
-   * of the cost of a single request to handle in ETH/LINK price between request and fulfillment time.
-   * @return fallbackWeiPerUnitLink - fallback ETH/LINK price in the case of a stale feed.
-   */
-  function getConfig()
-    external
-    view
-    returns (
-      uint16 minimumRequestBlockConfirmations,
-      uint32 fulfillmentFlatFeeLinkPPM,
-      uint32 maxGasLimit,
-      uint32 stalenessSeconds,
-      uint32 gasAfterPaymentCalculation,
-      uint96 minimumSubscriptionBalance,
-      int256 fallbackWeiPerUnitLink
-    );
-
   /**
    * @notice Request a set of random words.
    * @param keyHash - Corresponds to a particular oracle job which uses
@@ -47,7 +19,7 @@ interface VRFCoordinatorV2Interface {
    * may be slightly less than this amount because of gas used calling the function
    * (argument decoding etc.), so you may need to request slightly more than you expect
    * to have inside fulfillRandomWords. The acceptable range is
-   * [5000, maxGasLimit].
+   * [0, maxGasLimit]
    * @param numWords - The number of uint256 random values you'd like to receive
    * in your fulfillRandomWords callback. Note these numbers are expanded in a
    * secure way by the VRFCoordinator from a single random value supplied by the oracle.
@@ -119,18 +91,6 @@ interface VRFCoordinatorV2Interface {
    */
   function removeConsumer(uint64 subId, address consumer) external;
 
-  /**
-   * @notice Withdraw funds from a VRF subscription
-   * @param subId - ID of the subscription
-   * @param to - Where to send the withdrawn LINK to
-   * @param amount - How much to withdraw in juels
-   */
-  function defundSubscription(
-    uint64 subId,
-    address to,
-    uint96 amount
-  ) external;
-
   /**
    * @notice Cancel a subscription
    * @param subId - ID of the subscription

contracts/src/v0.8/tests/VRFConsumerV2.sol

@@ -33,6 +33,12 @@ contract VRFConsumerV2 is VRFConsumerBaseV2 {
     LINKTOKEN.transferAndCall(address(COORDINATOR), amount, abi.encode(s_subId));
   }
 
+  function topUpSubscription(uint96 amount) external {
+    require(s_subId != 0, "sub not set");
+    // Approve the link transfer.
+    LINKTOKEN.transferAndCall(address(COORDINATOR), amount, abi.encode(s_subId));
+  }
+
   function updateSubscription(address[] memory consumers) external {
     require(s_subId != 0, "subID not set");
     for (uint256 i = 0; i < consumers.length; i++) {

contracts/test/test-helpers/helpers.ts

@@ -1,5 +1,5 @@
 import { Contract, ContractTransaction } from 'ethers'
-import type { providers } from 'ethers'
+import { providers } from 'ethers'
 import { assert } from 'chai'
 import { ethers } from 'hardhat'
 import cbor from 'cbor'