feat: adopt ERC-8153 exportSelectors for on-chain facet self-description

CONTRIBUTING.md

@@ -18,10 +18,8 @@ forge build
 
 ## Running Tests
 
-Tests use FFI for selector extraction, so the `--ffi` flag is required:
-
 ```sh
-forge test --ffi -vvv
+forge test -vvv
 ```
 
 ## Making Changes
@@ -34,14 +32,15 @@ forge test --ffi -vvv
    - `src/initializers/` — Initializer contracts
 3. Add or update tests in `test/` to cover your changes.
 4. Run `forge fmt` to format your code.
-5. Ensure all tests pass with `forge test --ffi`.
+5. Ensure all tests pass with `forge test`.
 6. Open a pull request against `main`.
 
 ## Guidelines
 
 - Keep gas efficiency in mind — this library is optimized for minimal overhead.
 - Follow existing code style and naming conventions.
 - One logical change per PR — avoid bundling unrelated changes.
+- Selectors are self-reported on-chain via ERC-8153 `exportSelectors()`. When you add an external/public function to a facet, you MUST also add its selector to that facet's `exportSelectors()`, extend the expected set in `test/ExportSelectorsTester.t.sol`, and exercise it through the diamond with a routed-call test. A function omitted from `exportSelectors()` will not be cut in or routed — and no test will fail unless you add one.
 - Include test cases for both success and failure paths.
 
 ## Reporting Issues

foundry.toml

@@ -9,7 +9,7 @@ remappings = [
 ]
 optimizer_runs = 1_000_000
 via_ir = false
-ffi = true
+ffi = false
 
 [profile.ci]
 optimizer_runs = 1_000_000

script/DeployDiamond.s.sol

@@ -1,7 +1,7 @@
 // SPDX-License-Identifier: MIT
 pragma solidity ^0.8.20;
 
-import {GetSelectors} from "@diamond-test/helpers/GetSelectors.sol";
+import {Selectors} from "@diamond-test/helpers/Selectors.sol";
 import {MockDiamond} from "@diamond-test/mocks/MockDiamond.sol";
 import {DiamondCutFacet} from "@diamond/facets/DiamondCutFacet.sol";
 import {DiamondLoupeFacet} from "@diamond/facets/DiamondLoupeFacet.sol";
@@ -11,6 +11,7 @@ import {DiamondInit} from "@diamond/initializers/DiamondInit.sol";
 import {ERC165Init} from "@diamond/initializers/ERC165Init.sol";
 import {MultiInit} from "@diamond/initializers/MultiInit.sol";
 import {OwnableInit} from "@diamond/initializers/OwnableInit.sol";
+import {IFacet} from "@diamond/interfaces/IFacet.sol";
 import {ContextLib} from "@diamond/libraries/ContextLib.sol";
 import {FacetCut, FacetCutAction} from "@diamond/libraries/DiamondLib.sol";
 import {Script} from "forge-std/Script.sol";
@@ -20,7 +21,7 @@ import {Script} from "forge-std/Script.sol";
 /// @author David Dada
 ///
 /// @dev Uses Foundry's `Script` and a helper contract to deploy and wire up DiamondCutFacet, DiamondLoupeFacet, and OwnableFacet
-contract DeployDiamond is Script, GetSelectors {
+contract DeployDiamond is Script {
     /// @notice Executes the deployment of the Diamond contract with the initial facets and ERC165 interface setup
     /// @dev Broadcasts transactions using Foundry's scripting environment (`vm.startBroadcast()` and `vm.stopBroadcast()`).
     ///      Deploys three core facets, sets up DiamondArgs, encodes an initializer call, and constructs the Diamond.
@@ -39,32 +40,32 @@ contract DeployDiamond is Script, GetSelectors {
         // Create an array of FacetCut entries for standard facets
         FacetCut[] memory cut = new FacetCut[](4);
 
-        // Add DiamondCutFacet to the cut list
+        // Add DiamondCutFacet to the cut list (selectors read on-chain via ERC-8153 exportSelectors)
         cut[0] = FacetCut({
             facetAddress: address(diamondCutFacet),
             action: FacetCutAction.Add,
-            functionSelectors: _getSelectors("DiamondCutFacet")
+            functionSelectors: Selectors.decode(IFacet(address(diamondCutFacet)).exportSelectors())
         });
 
         // Add DiamondLoupeFacet to the cut list
         cut[1] = FacetCut({
             facetAddress: address(diamondLoupeFacet),
             action: FacetCutAction.Add,
-            functionSelectors: _getSelectors("DiamondLoupeFacet")
+            functionSelectors: Selectors.decode(IFacet(address(diamondLoupeFacet)).exportSelectors())
         });
 
         // Add ERC165Facet to the cut list
         cut[2] = FacetCut({
             facetAddress: address(erc165Facet),
             action: FacetCutAction.Add,
-            functionSelectors: _getSelectors("ERC165Facet")
+            functionSelectors: Selectors.decode(IFacet(address(erc165Facet)).exportSelectors())
         });
 
         // Add OwnableFacet to the cut list
         cut[3] = FacetCut({
             facetAddress: address(ownableFacet),
             action: FacetCutAction.Add,
-            functionSelectors: _getSelectors("OwnableFacet")
+            functionSelectors: Selectors.decode(IFacet(address(ownableFacet)).exportSelectors())
         });
 
         // Deploy the Diamond contract with the facets and initialization args

src/facets/DiamondCutFacet.sol

@@ -2,6 +2,7 @@
 pragma solidity ^0.8.20;
 
 import {IDiamondCut} from "@diamond/interfaces/IDiamondCut.sol";
+import {IFacet} from "@diamond/interfaces/IFacet.sol";
 import {DiamondLib, FacetCut} from "@diamond/libraries/DiamondLib.sol";
 import {OwnableLib} from "@diamond/libraries/OwnableLib.sol";
 
@@ -13,7 +14,7 @@ import {OwnableLib} from "@diamond/libraries/OwnableLib.sol";
 /// @dev Note:
 /// Remember to add the loupe functions from DiamondLoupeFacet to the diamond.
 /// The loupe functions are required by the EIP2535 Diamonds standard.
-contract DiamondCutFacet is IDiamondCut {
+contract DiamondCutFacet is IDiamondCut, IFacet {
     /// @notice Add/replace/remove any number of functions and optionally execute
     ///         a function with delegatecall
     /// @param _diamondCut Contains the facet addresses and function selectors
@@ -26,4 +27,9 @@ contract DiamondCutFacet is IDiamondCut {
         // Call the diamond cut function from the library
         DiamondLib.diamondCut(_diamondCut, _init, _calldata);
     }
+
+    /// @inheritdoc IFacet
+    function exportSelectors() external pure returns (bytes memory selectors_) {
+        selectors_ = abi.encodePacked(this.diamondCut.selector);
+    }
 }

src/facets/DiamondLoupeFacet.sol

@@ -2,6 +2,7 @@
 pragma solidity ^0.8.20;
 
 import {IDiamondLoupe} from "@diamond/interfaces/IDiamondLoupe.sol";
+import {IFacet} from "@diamond/interfaces/IFacet.sol";
 import {DiamondLib, DiamondStorage, Facet} from "@diamond/libraries/DiamondLib.sol";
 
 /// @title DiamondLoupeFacet
@@ -10,7 +11,7 @@ import {DiamondLib, DiamondStorage, Facet} from "@diamond/libraries/DiamondLib.s
 /// @author Modified by David Dada <[email protected]> (https://github.com/dadadave80)
 ///
 /// @dev Implements the IDiamondLoupe interface as defined in EIP-2535
-contract DiamondLoupeFacet is IDiamondLoupe {
+contract DiamondLoupeFacet is IDiamondLoupe, IFacet {
     /// @notice Gets all facet addresses and their function selectors.
     /// @return facets_ Facet
     function facets() external view returns (Facet[] memory facets_) {
@@ -44,4 +45,14 @@ contract DiamondLoupeFacet is IDiamondLoupe {
     function facetAddress(bytes4 _functionSelector) external view override returns (address) {
         return DiamondLib.diamondStorage().selectorToFacetAndPosition[_functionSelector].facetAddress;
     }
+
+    /// @inheritdoc IFacet
+    function exportSelectors() external pure returns (bytes memory selectors_) {
+        selectors_ = abi.encodePacked(
+            this.facets.selector,
+            this.facetFunctionSelectors.selector,
+            this.facetAddresses.selector,
+            this.facetAddress.selector
+        );
+    }
 }

src/facets/ERC165Facet.sol

@@ -1,13 +1,14 @@
 // SPDX-License-Identifier: MIT
 pragma solidity ^0.8.20;
 
+import {IFacet} from "@diamond/interfaces/IFacet.sol";
 import {ERC165Lib} from "@diamond/libraries/ERC165Lib.sol";
 
 /// @title ERC165Facet
 /// @notice Diamond facet that implements the ERC-165 standard interface detection
 /// @author David Dada <[email protected]> (https://github.com/dadadave80)
 /// @dev Delegates to ERC165Lib which hardcodes support for ERC-165, ERC-173, IDiamondCut, and IDiamondLoupe
-contract ERC165Facet {
+contract ERC165Facet is IFacet {
     /// @notice Query if a contract implements an interface
     /// @param _interfaceId The interface identifier, as specified in ERC-165
     /// @dev Interface identification is specified in ERC-165. This function
@@ -17,4 +18,9 @@ contract ERC165Facet {
     function supportsInterface(bytes4 _interfaceId) external view returns (bool) {
         return ERC165Lib.supportsInterface(_interfaceId);
     }
+
+    /// @inheritdoc IFacet
+    function exportSelectors() external pure returns (bytes memory selectors_) {
+        selectors_ = abi.encodePacked(this.supportsInterface.selector);
+    }
 }

src/facets/OwnableFacet.sol

@@ -1,6 +1,7 @@
 // SPDX-License-Identifier: MIT
 pragma solidity ^0.8.20;
 
+import {IFacet} from "@diamond/interfaces/IFacet.sol";
 import {OwnableLib} from "@diamond/libraries/OwnableLib.sol";
 
 /// @title OwnableRolesFacet
@@ -15,7 +16,7 @@ import {OwnableLib} from "@diamond/libraries/OwnableLib.sol";
 /// While the ownable portion follows
 /// [EIP-173](https://eips.ethereum.org/EIPS/eip-173) for compatibility,
 /// the nomenclature for the 2-step ownership handover may be unique to this codebase.
-contract OwnableFacet {
+contract OwnableFacet is IFacet {
     /*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
     /*                  PUBLIC UPDATE FUNCTIONS                   */
     /*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/
@@ -61,6 +62,23 @@ contract OwnableFacet {
         return OwnableLib.ownershipHandoverExpiresAt(_pendingOwner);
     }
 
+    /*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
+    /*                 ERC-8153 SELF-DESCRIPTION                  */
+    /*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/
+
+    /// @inheritdoc IFacet
+    function exportSelectors() external pure returns (bytes memory selectors_) {
+        selectors_ = abi.encodePacked(
+            this.transferOwnership.selector,
+            this.renounceOwnership.selector,
+            this.requestOwnershipHandover.selector,
+            this.cancelOwnershipHandover.selector,
+            this.completeOwnershipHandover.selector,
+            this.owner.selector,
+            this.ownershipHandoverExpiresAt.selector
+        );
+    }
+
     /*´:°•.°+.*•´.*:˚.°*.˚•´.°:°•.°•.*•´.*:˚.°*.˚•´.°:°•.°+.*•´.*:*/
     /*                         MODIFIERS                          */
     /*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/

src/interfaces/IFacet.sol

@@ -0,0 +1,24 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.20;
+
+/// @title IFacet
+/// @notice ERC-8153 facet self-description interface.
+/// @author David Dada <[email protected]> (https://github.com/dadadave80)
+///
+/// @dev Every facet reports its own function selectors on-chain, so upgraders and
+///      deployment tooling no longer depend on off-chain selector extraction.
+///      See https://eips.ethereum.org/EIPS/eip-8153.
+///
+/// @custom:security Selectors are SELF-REPORTED by the facet. Only build `FacetCut`s from the
+///      `exportSelectors()` of facets whose bytecode you trust (e.g. facets you deployed
+///      yourself). A malicious facet can claim selectors it does not implement — including
+///      `diamondCut` or ownership selectors — to hijack routing. `Add` cuts fail closed on
+///      selector collision, but `Replace` cuts and cuts on a fresh diamond do not.
+interface IFacet {
+    /// @notice Returns this facet's externally-callable function selectors, ABI-packed.
+    /// @dev The returned length is always a multiple of 4. `exportSelectors` MUST exclude
+    ///      itself: it is called directly on the facet address, never routed through the
+    ///      diamond, and every facet declares it (routing it would collide across facets).
+    /// @return selectors_ The facet's selectors packed as consecutive 4-byte values.
+    function exportSelectors() external pure returns (bytes memory selectors_);
+}

test/DiamondTester.t.sol

@@ -1,10 +1,12 @@
 // SPDX-License-Identifier: MIT
 pragma solidity ^0.8.20;
 
+import {Selectors} from "@diamond-test/helpers/Selectors.sol";
 import {Utils} from "@diamond-test/helpers/Utils.sol";
 import {DeployedDiamondState} from "@diamond-test/states/DeployedDiamondState.sol";
 import {IDiamondCut} from "@diamond/interfaces/IDiamondCut.sol";
 import {IDiamondLoupe} from "@diamond/interfaces/IDiamondLoupe.sol";
+import {IFacet} from "@diamond/interfaces/IFacet.sol";
 import {Facet} from "@diamond/libraries/DiamondLib.sol";
 
 /// @title DiamondTester
@@ -36,12 +38,12 @@ contract DiamondTester is DeployedDiamondState {
     /*              LOUPE — Inspecting the Cut                      */
     /*.•°:°.´+˚.*°.˚:*.´•*.+°.•°:´*.´•*.•°.•°:°.´:•˚°.*°.˚:*.´+°.•*/
 
-    /// @notice Every expected selector is registered under its facet
-    function testLoupe_SelectorsAreComplete() public {
+    /// @notice Every selector a facet self-reports (ERC-8153) is registered under that facet
+    function testLoupe_SelectorsAreComplete() public view {
         for (uint256 i; i < facetAddresses.length; ++i) {
-            bytes4[] memory fromGenSelectors = _getSelectors(facetNames[i]);
-            for (uint256 j; j < fromGenSelectors.length; ++j) {
-                assertEq(facetAddresses[i], diamondLoupe.facetAddress(fromGenSelectors[j]));
+            bytes4[] memory exported = Selectors.decode(IFacet(facetAddresses[i]).exportSelectors());
+            for (uint256 j; j < exported.length; ++j) {
+                assertEq(facetAddresses[i], diamondLoupe.facetAddress(exported[j]));
             }
         }
     }