✅ Improve tests

test/EIP7412.t.sol

@@ -2,30 +2,73 @@
 pragma solidity 0.8.20;
 
 import {EIP7412} from "src/utils/EIP7412.sol";
+import {
+    EIP7412Mock,
+    EIP7412MockRefund,
+    EIP7412MockRevert
+} from "test/utils/mocks/EIP7412Mock.sol";
 import {SynthetixMock} from "test/utils/mocks/SynthetixMock.sol";
 import {Test} from "lib/forge-std/src/Test.sol";
 
 contract EIP7412Test is Test, SynthetixMock {
+    EIP7412Mock eip7412Mock;
+    EIP7412MockRefund eip7412MockRefund;
+    EIP7412MockRevert eip7412MockRevert;
+
+    uint256 amount = 1 ether;
+
+    function setUp() public {
+        eip7412Mock = new EIP7412Mock();
+        eip7412MockRefund = new EIP7412MockRefund();
+        eip7412MockRevert = new EIP7412MockRevert();
+    }
+
     function test_fulfillOracleQuery(bytes calldata signedOffchainData)
         public
     {
-        address payable mock_eip7412_implementer = payable(address(0xE19));
+        EIP7412 eip7412 = new EIP7412();
+
+        uint256 preBalance = address(this).balance;
+        uint preBalanceeip7412Mock = address(eip7412Mock).balance;
+
+        eip7412.fulfillOracleQuery{value: amount}(
+            payable(address(eip7412Mock)), signedOffchainData
+        );
+
+        assertLt(address(this).balance, preBalance);
+        assertEq(address(eip7412Mock).balance, preBalanceeip7412Mock + amount);
+    }
+
+    function test_fulfillOracleQuery_refund(bytes calldata signedOffchainData)
+        public
+    {
+        EIP7412 eip7412 = new EIP7412();
 
-        mock_fulfillOracleQuery(mock_eip7412_implementer, signedOffchainData);
+        uint256 preBalance = address(this).balance;
+
+        // refunds are not supported
+        vm.expectRevert("EIP7412MockRefund");
+
+        eip7412.fulfillOracleQuery{value: amount}(
+            payable(address(eip7412MockRefund)), signedOffchainData
+        );
 
+        assert(address(this).balance == preBalance);
+    }
+
+    function test_fulfillOracleQuery_revert(bytes calldata signedOffchainData)
+        public
+    {
         EIP7412 eip7412 = new EIP7412();
 
         uint256 preBalance = address(this).balance;
 
-        (bool success,) = address(eip7412).call{value: 5 wei}(
-            abi.encodeWithSelector(
-                EIP7412.fulfillOracleQuery.selector,
-                mock_eip7412_implementer,
-                signedOffchainData
-            )
+        vm.expectRevert("EIP7412MockRevert");
+
+        eip7412.fulfillOracleQuery{value: amount}(
+            payable(address(eip7412MockRevert)), signedOffchainData
         );
 
-        assertTrue(success);
-        assertLt(address(this).balance, preBalance);
+        assert(address(this).balance == preBalance);
     }
 }

test/utils/mocks/EIP7412Mock.sol

@@ -0,0 +1,19 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+pragma solidity 0.8.20;
+
+contract EIP7412Mock {
+    function fulfillOracleQuery(bytes calldata) external payable {}
+}
+
+contract EIP7412MockRefund {
+    function fulfillOracleQuery(bytes calldata) external payable {
+        (bool success,) = msg.sender.call{value: msg.value}("");
+        require(success, "EIP7412MockRefund");
+    }
+}
+
+contract EIP7412MockRevert {
+    function fulfillOracleQuery(bytes calldata) external payable {
+        revert("EIP7412MockRevert");
+    }
+}

test/utils/mocks/SynthetixMock.sol

@@ -51,19 +51,6 @@ contract SynthetixMock is Test {
         );
     }
 
-    function mock_fulfillOracleQuery(
-        address EIP7412Implementer,
-        bytes calldata signedOffchainData
-    ) public {
-        vm.mockCall(
-            EIP7412Implementer,
-            abi.encodeWithSelector(
-                EIP7412.fulfillOracleQuery.selector, signedOffchainData
-            ),
-            abi.encode()
-        );
-    }
-
     function mock_getAccountOwner(
         address perpsMarketProxy,
         uint128 accountId,