add ERC165 to mock

Author: 0xCourtney

contracts/token/common/ERC2981/ERC2981Mock.sol

@@ -2,24 +2,33 @@
 
 pragma solidity ^0.8.8;
 
-import { ERC2981 } from './ERC2981.sol';
+import { ERC2981, IERC2981 } from './ERC2981.sol';
 import { ERC2981Storage } from './ERC2981Storage.sol';
 
-import { ERC165 } from '../../../introspection/ERC165.sol';
+import { IERC165, ERC165, ERC165Storage } from '../../../introspection/ERC165.sol';
 
 contract ERC2981Mock is ERC2981, ERC165 {
+    using ERC165Storage for ERC165Storage.Layout;
+
     constructor(
         uint16 defaultRoyaltyBPS,
         uint16[] memory royaltiesBPS,
         address defaultRoyaltyReceiver
     ) {
-        ERC2981Storage.Layout storage l = ERC2981Storage.layout();
+        {
+            ERC2981Storage.Layout storage l = ERC2981Storage.layout();
+            l.defaultRoyaltyBPS = defaultRoyaltyBPS;
+            l.defaultRoyaltyReceiver = defaultRoyaltyReceiver;
 
-        l.defaultRoyaltyBPS = defaultRoyaltyBPS;
-        l.defaultRoyaltyReceiver = defaultRoyaltyReceiver;
+            for (uint8 i = 0; i < royaltiesBPS.length; i++) {
+                l.royaltiesBPS[i] = royaltiesBPS[i];
+            }
+        }
 
-        for (uint8 i = 0; i < royaltiesBPS.length; i++) {
-            l.royaltiesBPS[i] = royaltiesBPS[i];
+        {
+            ERC165Storage.Layout storage l = ERC165Storage.layout();
+            l.setSupportedInterface(type(IERC165).interfaceId, true);
+            l.setSupportedInterface(type(IERC2981).interfaceId, true);
         }
     }