Add test for get_block_hash syscall

Author: cptartur

crates/forge/tests/data/simple_package_with_cheats/src/lib.cairo

@@ -5,6 +5,7 @@ pub trait IHelloStarknet<TContractState> {
     fn increase_balance(ref self: TContractState, amount: felt252);
     fn get_balance(self: @TContractState) -> felt252;
     fn get_block_number(self: @TContractState) -> u64;
+    fn get_block_hash(self: @TContractState) -> felt252;
 }
 
 #[starknet::interface]
@@ -91,8 +92,9 @@ pub mod HelloStarknetProxy {
 #[starknet::contract]
 pub mod HelloStarknet {
     use core::array::ArrayTrait;
-    use starknet::get_block_number;
     use starknet::storage::{StoragePointerReadAccess, StoragePointerWriteAccess};
+    use starknet::syscalls::get_block_hash_syscall;
+    use starknet::{SyscallResultTrait, get_block_number};
 
     #[storage]
     struct Storage {
@@ -114,5 +116,9 @@ pub mod HelloStarknet {
         fn get_block_number(self: @ContractState) -> u64 {
             get_block_number()
         }
+
+        fn get_block_hash(self: @ContractState) -> felt252 {
+            get_block_hash_syscall(100).unwrap_syscall()
+        }
     }
 }

crates/forge/tests/data/simple_package_with_cheats/tests/contract.cairo

@@ -6,7 +6,9 @@ use simple_package_with_cheats::{
     IHelloStarknetProxyDispatcherTrait,
 };
 use snforge_std::cheatcodes::contract_class::DeclareResultTrait;
-use snforge_std::{ContractClassTrait, declare, start_cheat_block_number_global};
+use snforge_std::{
+    ContractClassTrait, declare, start_cheat_block_hash_global, start_cheat_block_number_global,
+};
 use starknet::contract_address;
 
 #[test]
@@ -95,3 +97,19 @@ fn deploy_syscall() {
     let block_number = cheated_constructor_dispatcher.get_stored_block_number();
     assert(block_number == 123, 'block_number == 123');
 }
+
+#[test]
+fn block_hash() {
+    let contract = declare("HelloStarknet").unwrap().contract_class();
+    let constructor_calldata = @ArrayTrait::new();
+    let (contract_address, _) = contract.deploy(constructor_calldata).unwrap();
+    let dispatcher = IHelloStarknetDispatcher { contract_address };
+
+    let block_hash = dispatcher.get_block_hash();
+    assert(block_hash == 0, 'bloch_hash == 0');
+
+    start_cheat_block_hash_global(100, 111);
+
+    let block_hash = dispatcher.get_block_hash();
+    assert(block_hash == 111, 'bloch_hash == 111');
+}