add basic burn function

Author: aradix16

backend-sc/src/components/certificate/certificate.cairo

@@ -22,7 +22,7 @@ mod NFTComponent {
         +SRC5Component::HasComponent<TContractState>,
         impl ERC721: ERC721Component::HasComponent<TContractState>,
         > of INFTComponent<ComponentState<TContractState>> {
-
+            // internal
             fn initializer(
                 ref self: ComponentState<TContractState>,
                 name: ByteArray,
@@ -37,5 +37,10 @@ mod NFTComponent {
                 let mut erc721 = get_dep_component_mut!(ref self, ERC721);
                 erc721._mint(to, token_id);
             }
+
+            fn burn(ref self: ComponentState<TContractState>, token_id: u256) {
+                let mut erc721 = get_dep_component_mut!(ref self, ERC721);
+                erc721._burn(token_id);
+            }
         }
 }

backend-sc/src/components/certificate/interface.cairo

@@ -4,4 +4,5 @@ use starknet::ContractAddress;
 trait INFTComponent<TContractState> {
     fn initializer(ref self: TContractState, name: ByteArray, symbol: ByteArray, base_uri: ByteArray);
     fn mint(ref self: TContractState, to: ContractAddress, token_id: u256);
+    fn burn(ref self: TContractState, token_id: u256);
 }

backend-sc/tests/tests_certificate.cairo

@@ -56,3 +56,16 @@ fn test_mint_function() {
     let mut balance = erc721.balance_of(user_address);
     assert(balance == 1, 'Balance should be 1');
 }
+
+#[test]
+fn test_burn_function() {
+    let certificate_address = deploy_nft_certificate();
+    let certificate = INFTComponentDispatcher { contract_address: certificate_address };
+    let user_address: ContractAddress = contract_address_const::<'USER'>();
+    let erc721 = IERC721Dispatcher { contract_address: certificate_address };
+
+    certificate.mint(user_address, 1);
+    certificate.burn(1);
+    let mut balance = erc721.balance_of(user_address);
+    assert(balance == 0, 'Balance should be 0');
+}