feat: support EIP165 interface (#333)

* feat: support EIP165 interface

* fix comment contract name

---------

Co-authored-by: andreivladbrg <andreivladbrg@gmail.com>

src/abstracts/SablierFlowBase.sol

@@ -5,6 +5,7 @@ import { IERC20 } from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
 import { SafeERC20 } from "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
 import { ERC721 } from "@openzeppelin/contracts/token/ERC721/ERC721.sol";
 import { IERC721Metadata } from "@openzeppelin/contracts/token/ERC721/extensions/IERC721Metadata.sol";
+import { IERC165 } from "@openzeppelin/contracts/utils/introspection/IERC165.sol";
 import { UD21x18 } from "@prb/math/src/UD21x18.sol";
 import { UD60x18 } from "@prb/math/src/UD60x18.sol";
 
@@ -283,6 +284,12 @@ abstract contract SablierFlowBase is
         emit BatchMetadataUpdate({ _fromTokenId: 1, _toTokenId: nextStreamId - 1 });
     }
 
+    /// @inheritdoc ERC721
+    function supportsInterface(bytes4 interfaceId) public view override(IERC165, ERC721) returns (bool) {
+        // 0x49064906 is the ERC-165 interface ID required by ERC-4906
+        return interfaceId == 0x49064906 || super.supportsInterface(interfaceId);
+    }
+
     /*//////////////////////////////////////////////////////////////////////////
                             INTERNAL CONSTANT FUNCTIONS
     //////////////////////////////////////////////////////////////////////////*/

tests/integration/concrete/constructor.t.sol

@@ -25,6 +25,9 @@ contract Constructor_Integration_Concrete_Test is Integration_Test {
         address expectedAdmin = users.admin;
         assertEq(actualAdmin, expectedAdmin, "admin");
 
+        // {SablierV2Flow.supportsInterface}
+        assertTrue(constructedFlow.supportsInterface(0x49064906), "ERC-4906 interface ID");
+
         address actualNFTDescriptor = address(constructedFlow.nftDescriptor());
         address expectedNFTDescriptor = address(nftDescriptor);
         assertEq(actualNFTDescriptor, expectedNFTDescriptor, "nftDescriptor");