fix: remove constructor when generating interface

crates/cast/src/lib.rs

@@ -1609,7 +1609,10 @@ impl SimpleCast {
     /// Generates an interface in solidity from either a local file ABI or a verified contract on
     /// Etherscan. It returns a vector of [`InterfaceSource`] structs that contain the source of the
     /// interface and their name.
-    /// ```ignore
+    ///
+    /// Note: This removes the constructor from the ABI before generating the interface.
+    ///
+    /// ```no_run
     /// use cast::{AbiPath, SimpleCast as Cast};
     /// # async fn foo() -> eyre::Result<()> {
     /// let path =
@@ -1620,7 +1623,7 @@ impl SimpleCast {
     /// # }
     /// ```
     pub async fn generate_interface(address_or_path: AbiPath) -> Result<Vec<InterfaceSource>> {
-        let (contract_abis, contract_names) = match address_or_path {
+        let (mut contract_abis, contract_names) = match address_or_path {
             AbiPath::Local { path, name } => {
                 let file = std::fs::read_to_string(&path).wrap_err("unable to read abi file")?;
                 let obj: ContractObject = serde_json::from_str(&file)?;
@@ -1643,9 +1646,12 @@ impl SimpleCast {
             }
         };
         contract_abis
-            .iter()
+            .iter_mut()
             .zip(contract_names)
             .map(|(contract_abi, name)| {
+                // need to filter out the constructor
+                contract_abi.constructor.take();
+
                 let source = foundry_cli::utils::abi_to_solidity(contract_abi, &name)?;
                 Ok(InterfaceSource {
                     name,

crates/cast/tests/cli/main.rs

@@ -757,3 +757,37 @@ casttest!(balance, |_prj, cmd| {
     assert_ne!(usdt_result, "0x0000000000000000000000000000000000000000000000000000000000000000");
     assert_eq!(alias_result, usdt_result);
 });
+
+// tests that `cast interface` excludes the constructor
+// <https://github.com/alloy-rs/core/issues/555>
+casttest!(interface_no_constructor, |prj, cmd| {
+    let interface = include_str!("../fixtures/interface.json");
+
+    let path = prj.root().join("interface.json");
+    fs::write(&path, interface).unwrap();
+    // Call `cast find-block`
+    cmd.args(["interface"]).arg(&path);
+    let output = cmd.stdout_lossy();
+
+    let s = r#"// SPDX-License-Identifier: UNLICENSED
+pragma solidity ^0.8.4;
+
+interface Interface {
+    type SpendAssetsHandleType is uint8;
+
+    function getIntegrationManager() external view returns (address integrationManager_);
+    function lend(address _vaultProxy, bytes memory, bytes memory _assetData) external;
+    function parseAssetsForAction(address, bytes4 _selector, bytes memory _actionData)
+        external
+        view
+        returns (
+            SpendAssetsHandleType spendAssetsHandleType_,
+            address[] memory spendAssets_,
+            uint256[] memory spendAssetAmounts_,
+            address[] memory incomingAssets_,
+            uint256[] memory minIncomingAssetAmounts_
+        );
+    function redeem(address _vaultProxy, bytes memory, bytes memory _assetData) external;
+}"#;
+    assert_eq!(output.trim(), s);
+});

crates/cast/tests/fixtures/interface.json

@@ -0,0 +1,141 @@
+[
+  {
+    "type": "constructor",
+    "inputs": [
+      {
+        "name": "_integrationManager",
+        "type": "address",
+        "internalType": "address"
+      },
+      {
+        "name": "_addressListRegistry",
+        "type": "address",
+        "internalType": "address"
+      },
+      {
+        "name": "_aTokenListId",
+        "type": "uint256",
+        "internalType": "uint256"
+      },
+      {
+        "name": "_pool",
+        "type": "address",
+        "internalType": "address"
+      },
+      {
+        "name": "_referralCode",
+        "type": "uint16",
+        "internalType": "uint16"
+      }
+    ],
+    "stateMutability": "nonpayable"
+  },
+  {
+    "type": "function",
+    "name": "getIntegrationManager",
+    "inputs": [],
+    "outputs": [
+      {
+        "name": "integrationManager_",
+        "type": "address",
+        "internalType": "address"
+      }
+    ],
+    "stateMutability": "view"
+  },
+  {
+    "type": "function",
+    "name": "lend",
+    "inputs": [
+      {
+        "name": "_vaultProxy",
+        "type": "address",
+        "internalType": "address"
+      },
+      {
+        "name": "",
+        "type": "bytes",
+        "internalType": "bytes"
+      },
+      {
+        "name": "_assetData",
+        "type": "bytes",
+        "internalType": "bytes"
+      }
+    ],
+    "outputs": [],
+    "stateMutability": "nonpayable"
+  },
+  {
+    "type": "function",
+    "name": "parseAssetsForAction",
+    "inputs": [
+      {
+        "name": "",
+        "type": "address",
+        "internalType": "address"
+      },
+      {
+        "name": "_selector",
+        "type": "bytes4",
+        "internalType": "bytes4"
+      },
+      {
+        "name": "_actionData",
+        "type": "bytes",
+        "internalType": "bytes"
+      }
+    ],
+    "outputs": [
+      {
+        "name": "spendAssetsHandleType_",
+        "type": "uint8",
+        "internalType": "enum IIntegrationManager.SpendAssetsHandleType"
+      },
+      {
+        "name": "spendAssets_",
+        "type": "address[]",
+        "internalType": "address[]"
+      },
+      {
+        "name": "spendAssetAmounts_",
+        "type": "uint256[]",
+        "internalType": "uint256[]"
+      },
+      {
+        "name": "incomingAssets_",
+        "type": "address[]",
+        "internalType": "address[]"
+      },
+      {
+        "name": "minIncomingAssetAmounts_",
+        "type": "uint256[]",
+        "internalType": "uint256[]"
+      }
+    ],
+    "stateMutability": "view"
+  },
+  {
+    "type": "function",
+    "name": "redeem",
+    "inputs": [
+      {
+        "name": "_vaultProxy",
+        "type": "address",
+        "internalType": "address"
+      },
+      {
+        "name": "",
+        "type": "bytes",
+        "internalType": "bytes"
+      },
+      {
+        "name": "_assetData",
+        "type": "bytes",
+        "internalType": "bytes"
+      }
+    ],
+    "outputs": [],
+    "stateMutability": "nonpayable"
+  }
+]