From b78a45d53d3384f112ccefb750e6d1097a03daf6 Mon Sep 17 00:00:00 2001
From: Mubarak Muhammad Aminu <Mubarakaminu340@gmail.com>
Date: Mon, 7 Oct 2024 23:15:49 +0100
Subject: [PATCH] add burn function (#243)

* add burn function

* remove formatting

* unit test for burn function

* only token owner can burn a token

* should panic if wrong owner try to burn token

* rename test function name
---
 .../src/token/erc721_bridgeable.cairo         | 71 ++++++++++++++++++-
 .../starknet/src/token/interfaces.cairo       |  4 +-
 2 files changed, 73 insertions(+), 2 deletions(-)

diff --git a/apps/blockchain/starknet/src/token/erc721_bridgeable.cairo b/apps/blockchain/starknet/src/token/erc721_bridgeable.cairo
index 9ec9419c..b518b611 100644
--- a/apps/blockchain/starknet/src/token/erc721_bridgeable.cairo
+++ b/apps/blockchain/starknet/src/token/erc721_bridgeable.cairo
@@ -86,6 +86,13 @@ mod erc721_bridgeable {
             self.erc721._mint(to, token_id);
         }
 
+        fn burn(ref self: ContractState, token_id: u256) {
+            let token_owner = self.erc721.owner_of(token_id);
+            assert(token_owner == starknet::get_caller_address(), 'ERC721: only owner can burn');
+            self.erc721._burn(token_id);
+        }
+
+
         fn mint_from_bridge_uri(ref self: ContractState, to: ContractAddress, token_id: u256, token_uri: ByteArray) {
             IERC721Bridgeable::mint_from_bridge(ref self, to, token_id);
             self.token_uris.write(token_id, token_uri);
@@ -296,6 +303,68 @@ mod tests {
         assert_eq!(erc721.token_uri(0), "myuri", "bad uri");
     }
 
+
+   /// Should burn token from bridge call.
+    #[test]
+    fn test_burn_token() {
+        let BRIDGE = bridge_addr_mock();
+
+        let DUO_OWNER = starknet::contract_address_const::<128>();
+
+        let contract_address = deploy_everai_collection();
+
+        let erc721b = IERC721BridgeableDispatcher { contract_address };
+
+        // Mint a token first to be able to burn it later
+        start_prank(CheatTarget::One(contract_address), BRIDGE);
+        erc721b.mint_from_bridge(DUO_OWNER, 42_u256);
+        stop_prank(CheatTarget::One(contract_address));
+
+        // Check that the owner is set correctly after minting
+        let erc721 = IERC721Dispatcher { contract_address };
+        assert!(erc721.owner_of(42_u256) == DUO_OWNER, "bad owner after mint");
+
+        // Burn the token
+        start_prank(CheatTarget::One(contract_address), DUO_OWNER);
+        erc721b.burn(42_u256);
+        stop_prank(CheatTarget::One(contract_address));
+
+        // balance_of
+       
+        let balance = erc721.balance_of(DUO_OWNER);
+        assert(balance == 0, 'token was not burn');
+    
+
+    }
+
+  /// Should panic, only owner can burn
+    #[test]
+    #[should_panic(expected: ('ERC721: only owner can burn', ))]
+    fn should_panic_test_burn_token() {
+        let BRIDGE = bridge_addr_mock();
+
+        let DUO_OWNER = starknet::contract_address_const::<128>();
+
+        let contract_address = deploy_everai_collection();
+
+        let erc721b = IERC721BridgeableDispatcher { contract_address };
+
+        // Mint a token first to be able to burn it later
+        start_prank(CheatTarget::One(contract_address), BRIDGE);
+        erc721b.mint_from_bridge(DUO_OWNER, 42_u256);
+        stop_prank(CheatTarget::One(contract_address));
+
+        // Check that the owner is set correctly after minting
+        let erc721 = IERC721Dispatcher { contract_address };
+        assert!(erc721.owner_of(42_u256) == DUO_OWNER, "bad owner after mint");
+
+        // Burn the token by wrong owner
+        start_prank(CheatTarget::One(contract_address), BRIDGE);
+        erc721b.burn(42_u256);
+       
+
+    }
+
     /// Should not mint token if not bridge.
     #[test]
     #[should_panic(expected: ('ERC721: only bridge can mint', ))]
@@ -512,4 +581,4 @@ mod tests {
         assert_eq!(IERC721Dispatcher {contract_address}.token_uri(token_id), new_uri);
     }
 
-}
+}
\ No newline at end of file
diff --git a/apps/blockchain/starknet/src/token/interfaces.cairo b/apps/blockchain/starknet/src/token/interfaces.cairo
index 5d27fcf2..9d6163cb 100644
--- a/apps/blockchain/starknet/src/token/interfaces.cairo
+++ b/apps/blockchain/starknet/src/token/interfaces.cairo
@@ -7,7 +7,7 @@ trait IERC721<T> {
     fn owner_of(self: @T, token_id: u256) -> ContractAddress;
     fn token_uri(self: @T, token_id: u256) -> ByteArray;
     fn is_approved_for_all(self: @T, owner: ContractAddress, operator: ContractAddress) -> bool;
-
+    fn balance_of(self: @T, owner: ContractAddress) -> u256;
     fn set_approval_for_all(ref self: T, operator: ContractAddress, approved: bool);
     fn transfer_from(ref self: T, from: ContractAddress, to: ContractAddress, token_id: u256);
     fn approve(ref self: T, to: ContractAddress, token_id: u256);
@@ -30,6 +30,8 @@ trait IERC721Mintable<T> {
 /// ERC721 that can be manipulated by the bridge.
 #[starknet::interface]
 trait IERC721Bridgeable<T> {
+    fn burn(ref self: T, token_id: u256);
+
     fn mint_from_bridge(ref self: T, to: ContractAddress, token_id: u256);
 
     fn mint_from_bridge_uri(ref self: T, to: ContractAddress, token_id: u256, token_uri: ByteArray);