test: add extreme case tests

packages/lsp26-contracts/contracts/mock/ReturnBomb.sol

@@ -0,0 +1,26 @@
+// SPDX-License-Identifier: Apache-2.0
+pragma solidity ^0.8.17;
+
+// interfaces
+import {
+    ILSP1UniversalReceiver
+} from "@lukso/lsp1-contracts/contracts/ILSP1UniversalReceiver.sol";
+
+contract ReturnBomb is ILSP1UniversalReceiver {
+    uint256 public counter;
+
+    function supportsInterface(bytes4) external pure returns (bool) {
+        return true;
+    }
+
+    function universalReceiver(
+        bytes32,
+        bytes memory
+    ) external payable returns (bytes memory) {
+        ++counter;
+        // solhint-disable-next-line no-inline-assembly
+        assembly {
+            revert(0, 10000)
+        }
+    }
+}

packages/lsp26-contracts/contracts/mock/SelfDestructOnInterfaceCheck.sol

@@ -0,0 +1,23 @@
+// SPDX-License-Identifier: Apache-2.0
+pragma solidity ^0.8.17;
+
+// interfaces
+import {
+    ILSP1UniversalReceiver
+} from "@lukso/lsp1-contracts/contracts/ILSP1UniversalReceiver.sol";
+
+contract SelfDestructOnInterfaceCheck is ILSP1UniversalReceiver {
+    uint256 public counter;
+
+    function supportsInterface(bytes4) external returns (bool) {
+        selfdestruct(payable(msg.sender));
+        return true;
+    }
+
+    function universalReceiver(
+        bytes32,
+        bytes memory
+    ) external payable returns (bytes memory) {
+        return "";
+    }
+}

packages/lsp26-contracts/tests/LSP26FollowerSystem.test.ts

@@ -15,6 +15,10 @@ import {
   LSP0ERC725Account__factory,
   RevertOnFollow__factory,
   RevertOnFollow,
+  ReturnBomb__factory,
+  ReturnBomb,
+  SelfDestructOnInterfaceCheck__factory,
+  SelfDestructOnInterfaceCheck,
 } from '../types';
 
 describe('testing `LSP26FollowerSystem`', () => {
@@ -115,6 +119,66 @@ describe('testing `LSP26FollowerSystem`', () => {
     });
   });
 
+  describe('testing following/unfollowing a contract that self destructs on interface check', async () => {
+    let selfDestruct: SelfDestructOnInterfaceCheck;
+
+    before(async () => {
+      selfDestruct = await new SelfDestructOnInterfaceCheck__factory(context.owner).deploy();
+    });
+
+    it('should pass following', async () => {
+      await context.followerSystem.connect(context.owner).follow(await selfDestruct.getAddress());
+
+      expect(
+        await context.followerSystem.isFollowing(
+          context.owner.address,
+          await selfDestruct.getAddress(),
+        ),
+      ).to.be.true;
+    });
+
+    it('should pass unfollowing', async () => {
+      await context.followerSystem.connect(context.owner).unfollow(await selfDestruct.getAddress());
+
+      expect(
+        await context.followerSystem.isFollowing(
+          context.owner.address,
+          await selfDestruct.getAddress(),
+        ),
+      ).to.be.false;
+    });
+  });
+
+  describe('testing following/unfollowing a contract with return bomb', () => {
+    let returnBomb: ReturnBomb;
+
+    before(async () => {
+      returnBomb = await new ReturnBomb__factory(context.owner).deploy();
+    });
+
+    it('should pass following', async () => {
+      await context.followerSystem.connect(context.owner).follow(await returnBomb.getAddress());
+
+      expect(
+        await context.followerSystem.isFollowing(
+          context.owner.address,
+          await returnBomb.getAddress(),
+        ),
+      ).to.be.true;
+    });
+
+    it('should pass unfollowing', async () => {
+      await context.followerSystem.connect(context.owner).unfollow(await returnBomb.getAddress());
+
+      expect(
+        await context.followerSystem.isFollowing(
+          context.owner.address,
+          await returnBomb.getAddress(),
+        ),
+      ).to.be.false;
+    });
+  });
+
   describe.skip('gas tests', () => {
     const gasCostResult: {
       followingGasCost?: number[];