feat: reimplement erc165 for erc20

CHANGELOG.md

@@ -20,7 +20,6 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Changed (Breaking)
 
 - Refactor `Erc20Permit` extension to be a composition of `Erc20` and `Nonces` contracts. #574
-- Remove `IErc165` implementations for ERC-20 contracts to align with Solidity versions. #570
 - Replace `VestingWallet::receive_ether` with dedicated `receive` function. #529
 - Extract `IAccessControl` trait from `AccessControl` contract. #527
 - Bump Stylus SDK to v0.8.1 #587

contracts/src/token/erc20/extensions/metadata.rs

@@ -4,11 +4,15 @@ use alloc::{string::String, vec, vec::Vec};
 
 use openzeppelin_stylus_proc::interface_id;
 use stylus_sdk::{
+    alloy_primitives::FixedBytes,
     prelude::*,
     stylus_proc::{public, storage},
 };
 
-use crate::utils::Metadata;
+use crate::utils::{
+    introspection::erc165::{Erc165, IErc165},
+    Metadata,
+};
 
 /// Number of decimals used by default on implementors of [`Metadata`].
 pub const DEFAULT_DECIMALS: u8 = 18;
@@ -73,14 +77,35 @@ impl IErc20Metadata for Erc20Metadata {
     }
 }
 
+impl IErc165 for Erc20Metadata {
+    fn supports_interface(interface_id: FixedBytes<4>) -> bool {
+        <Self as IErc20Metadata>::INTERFACE_ID
+            == u32::from_be_bytes(*interface_id)
+            || Erc165::supports_interface(interface_id)
+    }
+}
+
 #[cfg(all(test, feature = "std"))]
 mod tests {
-    use super::{Erc20Metadata, IErc20Metadata};
+    use super::{Erc20Metadata, IErc165, IErc20Metadata};
 
     #[motsu::test]
     fn interface_id() {
         let actual = <Erc20Metadata as IErc20Metadata>::INTERFACE_ID;
         let expected = 0xa219a025;
         assert_eq!(actual, expected);
     }
+
+    #[motsu::test]
+    fn supports_interface() {
+        assert!(Erc20Metadata::supports_interface(
+            <Erc20Metadata as IErc20Metadata>::INTERFACE_ID.into()
+        ));
+        assert!(Erc20Metadata::supports_interface(
+            <Erc20Metadata as IErc165>::INTERFACE_ID.into()
+        ));
+
+        let fake_interface_id = 0x12345678u32;
+        assert!(!Erc20Metadata::supports_interface(fake_interface_id.into()));
+    }
 }

contracts/src/token/erc20/mod.rs

@@ -6,7 +6,7 @@
 //! [`Erc20`] applications.
 use alloc::{vec, vec::Vec};
 
-use alloy_primitives::{Address, U256};
+use alloy_primitives::{Address, FixedBytes, U256};
 use openzeppelin_stylus_proc::interface_id;
 use stylus_sdk::{
     call::MethodError,
@@ -16,8 +16,9 @@ use stylus_sdk::{
     stylus_proc::{public, SolidityError},
 };
 
-use crate::utils::math::storage::{
-    AddAssignChecked, AddAssignUnchecked, SubAssignUnchecked,
+use crate::utils::{
+    introspection::erc165::{Erc165, IErc165},
+    math::storage::{AddAssignChecked, AddAssignUnchecked, SubAssignUnchecked},
 };
 
 pub mod extensions;
@@ -572,13 +573,20 @@ impl Erc20 {
     }
 }
 
+impl IErc165 for Erc20 {
+    fn supports_interface(interface_id: FixedBytes<4>) -> bool {
+        <Self as IErc20>::INTERFACE_ID == u32::from_be_bytes(*interface_id)
+            || Erc165::supports_interface(interface_id)
+    }
+}
+
 #[cfg(all(test, feature = "std"))]
 mod tests {
     use alloy_primitives::{uint, Address, U256};
     use motsu::prelude::Contract;
     use stylus_sdk::prelude::TopLevelStorage;
 
-    use super::{Erc20, Error, IErc20};
+    use super::{Erc20, Error, IErc165, IErc20};
 
     unsafe impl TopLevelStorage for Erc20 {}
 
@@ -936,5 +944,22 @@ mod tests {
         let actual = <Erc20 as IErc20>::INTERFACE_ID;
         let expected = 0x36372b07;
         assert_eq!(actual, expected);
+
+        let actual = <Erc20 as IErc165>::INTERFACE_ID;
+        let expected = 0x01ffc9a7;
+        assert_eq!(actual, expected);
+    }
+
+    #[motsu::test]
+    fn supports_interface() {
+        assert!(Erc20::supports_interface(
+            <Erc20 as IErc20>::INTERFACE_ID.into()
+        ));
+        assert!(Erc20::supports_interface(
+            <Erc20 as IErc165>::INTERFACE_ID.into()
+        ));
+
+        let fake_interface_id = 0x12345678u32;
+        assert!(!Erc20::supports_interface(fake_interface_id.into()));
     }
 }

examples/erc20-permit/src/lib.rs

@@ -20,6 +20,7 @@ struct Erc20PermitExample {
     #[borrow]
     pub erc20_permit: Erc20Permit<Eip712>,
 }
+
 #[storage]
 struct Eip712 {}
 

examples/erc20/src/lib.rs

@@ -3,13 +3,13 @@ extern crate alloc;
 
 use alloc::vec::Vec;
 
-use alloy_primitives::{Address, U256};
+use alloy_primitives::{Address, FixedBytes, U256};
 use openzeppelin_stylus::{
     token::erc20::{
         extensions::{capped, Capped, Erc20Metadata, IErc20Burnable},
         Erc20, IErc20,
     },
-    utils::Pausable,
+    utils::{introspection::erc165::IErc165, Pausable},
 };
 use stylus_sdk::prelude::*;
 
@@ -105,6 +105,11 @@ impl Erc20Example {
         self.erc20.transfer_from(from, to, value).map_err(|e| e.into())
     }
 
+    fn supports_interface(interface_id: FixedBytes<4>) -> bool {
+        Erc20::supports_interface(interface_id)
+            || Erc20Metadata::supports_interface(interface_id)
+    }
+
     /// WARNING: These functions are intended for **testing purposes** only. In
     /// **production**, ensure strict access control to prevent unauthorized
     /// pausing or unpausing, which can disrupt contract functionality. Remove

examples/erc20/tests/abi/mod.rs

@@ -25,6 +25,8 @@ sol!(
         function pause() external;
         function unpause() external;
 
+        function supportsInterface(bytes4 interface_id) external view returns (bool supportsInterface);
+
         error EnforcedPause();
         error ExpectedPause();
 

examples/erc20/tests/erc20.rs

@@ -1362,3 +1362,56 @@ async fn error_when_transfer_from(alice: Account, bob: Account) -> Result<()> {
 
     Ok(())
 }
+
+// ============================================================================
+// Integration Tests: ERC-165 Support Interface
+// ============================================================================
+
+#[e2e::test]
+async fn supports_interface(alice: Account) -> Result<()> {
+    let contract_addr = alice
+        .as_deployer()
+        .with_default_constructor::<constructorCall>()
+        .deploy()
+        .await?
+        .address()?;
+    let contract = Erc20::new(contract_addr, &alice.wallet);
+
+    let invalid_interface_id: u32 = 0xffffffff;
+    let supports_interface = contract
+        .supportsInterface(invalid_interface_id.into())
+        .call()
+        .await?
+        .supportsInterface;
+
+    assert!(!supports_interface);
+
+    let erc20_interface_id: u32 = 0x36372b07;
+    let supports_interface = contract
+        .supportsInterface(erc20_interface_id.into())
+        .call()
+        .await?
+        .supportsInterface;
+
+    assert!(supports_interface);
+
+    let erc165_interface_id: u32 = 0x01ffc9a7;
+    let supports_interface = contract
+        .supportsInterface(erc165_interface_id.into())
+        .call()
+        .await?
+        .supportsInterface;
+
+    assert!(supports_interface);
+
+    let erc20_metadata_interface_id: u32 = 0xa219a025;
+    let supports_interface = contract
+        .supportsInterface(erc20_metadata_interface_id.into())
+        .call()
+        .await?
+        .supportsInterface;
+
+    assert!(supports_interface);
+
+    Ok(())
+}