feat: erc721 holder example

Cargo.toml

@@ -15,6 +15,7 @@ members = [
   "examples/erc20-wrapper",
   "examples/erc721",
   "examples/erc721-consecutive",
+  "examples/erc721-holder",
   "examples/erc721-metadata",
   "examples/erc721-wrapper",
   "examples/erc1155",
@@ -48,6 +49,7 @@ default-members = [
   "examples/erc20-wrapper",
   "examples/erc721",
   "examples/erc721-consecutive",
+  "examples/erc721-holder",
   "examples/erc721-metadata",
   "examples/erc721-wrapper",
   "examples/erc1155",

examples/erc721-holder/Cargo.toml

@@ -0,0 +1,30 @@
+[package]
+name = "erc721-holder-example"
+edition.workspace = true
+license.workspace = true
+repository.workspace = true
+publish = false
+version.workspace = true
+
+[dependencies]
+openzeppelin-stylus.workspace = true
+alloy-primitives.workspace = true
+alloy-sol-types.workspace = true
+stylus-sdk.workspace = true
+
+[dev-dependencies]
+alloy.workspace = true
+e2e.workspace = true
+tokio.workspace = true
+eyre.workspace = true
+
+[lib]
+crate-type = ["lib", "cdylib"]
+
+[features]
+e2e = []
+export-abi = ["openzeppelin-stylus/export-abi"]
+
+[[bin]]
+name = "erc721-holder-example"
+path = "src/main.rs"

examples/erc721-holder/src/lib.rs

@@ -0,0 +1,42 @@
+#![cfg_attr(not(any(test, feature = "export-abi")), no_main)]
+extern crate alloc;
+
+use openzeppelin_stylus::token::erc721::{
+    receiver::IErc721Receiver, utils::Erc721Holder,
+};
+use stylus_sdk::{
+    abi::Bytes,
+    alloy_primitives::{aliases::B32, Address, U256},
+    prelude::*,
+};
+
+#[entrypoint]
+#[storage]
+struct Erc721HolderExample {
+    holder: Erc721Holder,
+}
+
+#[public]
+#[implements(IErc721Receiver<Error = Vec<u8>>)]
+impl Erc721HolderExample {
+    #[constructor]
+    pub fn constructor(&mut self) -> Result<(), Vec<u8>> {
+        Ok(())
+    }
+}
+
+#[public]
+impl IErc721Receiver for Erc721HolderExample {
+    type Error = Vec<u8>;
+
+    #[selector(name = "onERC721Received")]
+    fn on_erc721_received(
+        &mut self,
+        operator: Address,
+        from: Address,
+        token_id: U256,
+        data: Bytes,
+    ) -> Result<B32, Self::Error> {
+        self.holder.on_erc721_received(operator, from, token_id, data)
+    }
+}

examples/erc721-holder/src/main.rs

@@ -0,0 +1,10 @@
+#![cfg_attr(not(any(test, feature = "export-abi")), no_main)]
+
+#[cfg(not(any(test, feature = "export-abi")))]
+#[no_mangle]
+pub extern "C" fn main() {}
+
+#[cfg(feature = "export-abi")]
+fn main() {
+    erc721_holder_example::print_from_args();
+}

examples/erc721-holder/tests/abi/mod.rs

@@ -0,0 +1,14 @@
+#![allow(dead_code)]
+use alloy::sol;
+
+sol!(
+    #[sol(rpc)]
+    contract Erc721HolderExample {
+        function onERC721Received(
+            address operator,
+            address from,
+            uint256 tokenId,
+            bytes calldata data
+        ) external returns (bytes4);
+    }
+);

examples/erc721-holder/tests/erc721-holder.rs

@@ -0,0 +1,51 @@
+#![cfg(feature = "e2e")]
+
+use abi::Erc721HolderExample;
+use alloy::primitives::{Bytes, U256};
+use e2e::{constructor, Account};
+use eyre::Result;
+use openzeppelin_stylus::token::erc721::RECEIVER_FN_SELECTOR;
+
+mod abi;
+
+#[e2e::test]
+async fn returns_correct_selector(alice: Account) -> Result<()> {
+    let contract_addr = alice
+        .as_deployer()
+        .with_constructor(constructor!())
+        .deploy()
+        .await?
+        .contract_address;
+
+    let contract = Erc721HolderExample::new(contract_addr, &alice.wallet);
+
+    // call without data.
+    let interface_selector = contract
+        .onERC721Received(
+            alice.address(),
+            alice.address(),
+            U256::from(1),
+            Bytes::new(),
+        )
+        .call()
+        .await?
+        ._0;
+
+    assert_eq!(RECEIVER_FN_SELECTOR, interface_selector);
+
+    // call with data.
+    let interface_selector = contract
+        .onERC721Received(
+            alice.address(),
+            alice.address(),
+            U256::from(42),
+            Bytes::from(vec![0xde, 0xad, 0xbe, 0xef]),
+        )
+        .call()
+        .await?
+        ._0;
+
+    assert_eq!(RECEIVER_FN_SELECTOR, interface_selector);
+
+    Ok(())
+}