feat: add tests

contracts/mocks/ERC1363ReceiverMock.sol

@@ -0,0 +1,28 @@
+// SPDX-License-Identifier: MIT
+
+pragma solidity ^0.8.0;
+
+import "../token/ERC1363/IERC1363Receiver.sol";
+
+contract ERC1363ReceiverMock is IERC1363Receiver {
+    bytes4 private _retval;
+    bool private _reverts;
+
+    event Received(address operator, address sender, uint256 amount, bytes data, uint256 gas);
+
+    constructor(bytes4 retval, bool reverts) {
+        _retval = retval;
+        _reverts = reverts;
+    }
+
+    function onTransferReceived(
+        address operator,
+        address sender,
+        uint256 amount,
+        bytes memory data
+    ) public override returns (bytes4) {
+        require(!_reverts, "ERC1363ReceiverMock: throwing");
+        emit Received(operator, sender, amount, data, gasleft());
+        return _retval;
+    }
+}

contracts/mocks/ERC1363SpenderMock.sol

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+// SPDX-License-Identifier: MIT
+
+pragma solidity ^0.8.0;
+
+import "../token/ERC1363/IERC1363Spender.sol";
+
+contract ERC1363SpenderMock is IERC1363Spender {
+    bytes4 private _retval;
+    bool private _reverts;
+
+    event Approved(address sender, uint256 amount, bytes data, uint256 gas);
+
+    constructor(bytes4 retval, bool reverts) {
+        _retval = retval;
+        _reverts = reverts;
+    }
+
+    function onApprovalReceived(
+        address sender,
+        uint256 amount,
+        bytes memory data
+    ) public override returns (bytes4) {
+        require(!_reverts, "ERC1363SpenderMock: throwing");
+        emit Approved(sender, amount, data, gasleft());
+        return _retval;
+    }
+}