simplify getTransferValidationFunction(), add test

src/clones/ERC1155ContractMetadataCloneable.sol

@@ -14,7 +14,7 @@ import {
     ILegacyCreatorToken
 } from "../interfaces/ICreatorToken.sol";
 
-import { ITransferValidator } from "../interfaces/ITransferValidator.sol";
+import { ITransferValidator1155 } from "../interfaces/ITransferValidator.sol";
 
 import { TokenTransferValidator } from "../lib/TokenTransferValidator.sol";
 
@@ -324,11 +324,7 @@ contract ERC1155ContractMetadataCloneable is
         pure
         returns (bytes4 functionSignature, bool isViewFunction)
     {
-        functionSignature = bytes4(
-            keccak256(
-                "validateTransfer(address,address,address,uint256,uint256)"
-            )
-        );
+        functionSignature = ITransferValidator1155.validateTransfer.selector;
         isViewFunction = true;
     }
 
@@ -360,7 +356,7 @@ contract ERC1155ContractMetadataCloneable is
             // Call the transfer validator if one is set.
             if (_transferValidator != address(0)) {
                 for (uint256 i = 0; i < ids.length; i++) {
-                    ITransferValidator(_transferValidator).validateTransfer(
+                    ITransferValidator1155(_transferValidator).validateTransfer(
                         msg.sender,
                         from,
                         to,

src/interfaces/ITransferValidator.sol

@@ -1,17 +1,18 @@
 // SPDX-License-Identifier: MIT
 pragma solidity ^0.8.17;
 
-interface ITransferValidator {
-    /// @notice Ensure that a transfer has been authorized for a specific tokenId.
+interface ITransferValidator721 {
+    /// @notice Ensure that a transfer has been authorized for a specific tokenId
     function validateTransfer(
         address caller,
         address from,
         address to,
         uint256 tokenId
     ) external view;
+}
 
-    /// @notice Ensure that a transfer has been authorized for a specific amount of
-    ///         a specific tokenId, and reduce the transferable amount remaining.
+interface ITransferValidator1155 {
+    /// @notice Ensure that a transfer has been authorized for a specific amount of a specific tokenId, and reduce the transferable amount remaining
     function validateTransfer(
         address caller,
         address from,

src/lib/ERC1155ContractMetadata.sol

@@ -14,7 +14,7 @@ import {
     ILegacyCreatorToken
 } from "../interfaces/ICreatorToken.sol";
 
-import { ITransferValidator } from "../interfaces/ITransferValidator.sol";
+import { ITransferValidator1155 } from "../interfaces/ITransferValidator.sol";
 
 import { TokenTransferValidator } from "./TokenTransferValidator.sol";
 
@@ -322,11 +322,7 @@ contract ERC1155ContractMetadata is
         pure
         returns (bytes4 functionSignature, bool isViewFunction)
     {
-        functionSignature = bytes4(
-            keccak256(
-                "validateTransfer(address,address,address,uint256,uint256)"
-            )
-        );
+        functionSignature = ITransferValidator1155.validateTransfer.selector;
         isViewFunction = true;
     }
 
@@ -358,7 +354,7 @@ contract ERC1155ContractMetadata is
             // Call the transfer validator if one is set.
             if (_transferValidator != address(0)) {
                 for (uint256 i = 0; i < ids.length; i++) {
-                    ITransferValidator(_transferValidator).validateTransfer(
+                    ITransferValidator1155(_transferValidator).validateTransfer(
                         msg.sender,
                         from,
                         to,

src/lib/ERC721ContractMetadata.sol

@@ -12,7 +12,7 @@ import {
     ILegacyCreatorToken
 } from "../interfaces/ICreatorToken.sol";
 
-import { ITransferValidator } from "../interfaces/ITransferValidator.sol";
+import { ITransferValidator721 } from "../interfaces/ITransferValidator.sol";
 
 import { TokenTransferValidator } from "./TokenTransferValidator.sol";
 
@@ -290,9 +290,7 @@ contract ERC721ContractMetadata is
         pure
         returns (bytes4 functionSignature, bool isViewFunction)
     {
-        functionSignature = bytes4(
-            keccak256("validateTransfer(address,address,address,uint256)")
-        );
+        functionSignature = ITransferValidator721.validateTransfer.selector;
         isViewFunction = false;
     }
 
@@ -317,7 +315,7 @@ contract ERC721ContractMetadata is
         if (from != address(0) && to != address(0)) {
             // Call the transfer validator if one is set.
             if (_transferValidator != address(0)) {
-                ITransferValidator(_transferValidator).validateTransfer(
+                ITransferValidator721(_transferValidator).validateTransfer(
                     msg.sender,
                     from,
                     to,

src/test/MockTransferValidator.sol

@@ -1,9 +1,15 @@
 // SPDX-License-Identifier: Unlicense
 pragma solidity ^0.8.17;
 
-import { ITransferValidator } from "../interfaces/ITransferValidator.sol";
+import {
+    ITransferValidator721,
+    ITransferValidator1155
+} from "../interfaces/ITransferValidator.sol";
 
-contract MockTransferValidator is ITransferValidator {
+contract MockTransferValidator is
+    ITransferValidator721,
+    ITransferValidator1155
+{
     bool internal _revertOnValidate;
 
     constructor(bool revertOnValidate) {
@@ -25,10 +31,10 @@ contract MockTransferValidator is ITransferValidator {
     }
 
     function validateTransfer(
-        address, /* caller */
-        address, /* from */
-        address, /* to */
-        uint256, /* tokenId */
+        address /* caller */,
+        address /* from */,
+        address /* to */,
+        uint256 /* tokenId */,
         uint256 /* amount */
     ) external view {
         if (_revertOnValidate) {

test/foundry/TokenTransferValidator.t.sol

@@ -7,6 +7,11 @@ import { ERC721SeaDrop } from "seadrop/ERC721SeaDrop.sol";
 
 import { ERC1155SeaDrop } from "seadrop/ERC1155SeaDrop.sol";
 
+import {
+    ITransferValidator721,
+    ITransferValidator1155
+} from "seadrop/interfaces/ITransferValidator.sol";
+
 import { MockTransferValidator } from "seadrop/test/MockTransferValidator.sol";
 
 import { Ownable } from "solady/src/auth/Ownable.sol";
@@ -32,11 +37,7 @@ contract ERC1155SeaDropWithMint is ERC1155SeaDrop {
         string memory symbol_
     ) ERC1155SeaDrop(allowedConfigurer, allowedSeaport, name_, symbol_) {}
 
-    function mint(
-        address to,
-        uint256 id,
-        uint256 amount
-    ) public onlyOwner {
+    function mint(address to, uint256 id, uint256 amount) public onlyOwner {
         _mint(to, id, amount, "");
     }
 }
@@ -55,10 +56,20 @@ contract TokenTransferValidatorTest is SeaDrop721Test {
     function setUp() public override {
         super.setUp();
 
-        token721 = new ERC721SeaDropWithMint(address(0), allowedSeaport, "", "");
+        token721 = new ERC721SeaDropWithMint(
+            address(0),
+            allowedSeaport,
+            "",
+            ""
+        );
         token721.setMaxSupply(10);
 
-        token1155 = new ERC1155SeaDropWithMint(address(0), allowedSeaport, "", "");
+        token1155 = new ERC1155SeaDropWithMint(
+            address(0),
+            allowedSeaport,
+            "",
+            ""
+        );
         token1155.setMaxSupply(1, 10);
         token1155.setMaxSupply(2, 10);
     }
@@ -185,4 +196,24 @@ contract TokenTransferValidatorTest is SeaDrop721Test {
             ""
         );
     }
+
+    function testERC721GetTransferValidationFunction() public {
+        (bytes4 functionSignature, bool isViewFunction) = token721
+            .getTransferValidationFunction();
+        assertEq(
+            functionSignature,
+            ITransferValidator721.validateTransfer.selector
+        );
+        assertEq(isViewFunction, false);
+    }
+
+    function testERC1155GetTransferValidationFunction() public {
+        (bytes4 functionSignature, bool isViewFunction) = token1155
+            .getTransferValidationFunction();
+        assertEq(
+            functionSignature,
+            ITransferValidator1155.validateTransfer.selector
+        );
+        assertEq(isViewFunction, true);
+    }
 }