itest for block.difficulty (#10263)

itests/contracts/GetDifficulty.hex

@@ -0,0 +1 @@
+608060405234801561001057600080fd5b5060b58061001f6000396000f3fe6080604052348015600f57600080fd5b506004361060285760003560e01c8063b6baffe314602d575b600080fd5b60336047565b604051603e91906066565b60405180910390f35b600044905090565b6000819050919050565b606081604f565b82525050565b6000602082019050607960008301846059565b9291505056fea2646970667358221220c113f1abaabaed6a0324d363896b0d15a8bca7b9a540948a5be5b636a12a534f64736f6c63430008110033

itests/contracts/GetDifficulty.sol

@@ -0,0 +1,9 @@
+// SPDX-License-Identifier: MIT
+pragma solidity >=0.8.17;
+
+contract GetDifficulty {
+  function getDifficulty () public view returns (uint256) {
+    return block.difficulty;
+  }
+}
+

itests/fevm_test.go

@@ -855,3 +855,16 @@ func TestFEVMProxyUpgradeable(t *testing.T) {
 	_, _, err := client.EVM().InvokeContractByFuncName(ctx, fromAddr, contractAddr, "test()", []byte{})
 	require.NoError(t, err)
 }
+
+func TestFEVMGetBlockDifficulty(t *testing.T) {
+	ctx, cancel, client := kit.SetupFEVMTest(t)
+	defer cancel()
+
+	//install contract
+	filenameActor := "contracts/GetDifficulty.hex"
+	fromAddr, contractAddr := client.EVM().DeployContractFromFilename(ctx, filenameActor)
+
+	ret, _, err := client.EVM().InvokeContractByFuncName(ctx, fromAddr, contractAddr, "getDifficulty()", []byte{})
+	require.NoError(t, err)
+	require.Equal(t, len(ret), 32)
+}