ci: Add Foundry tooling integration test

.github/workflows/foundry.yml

@@ -0,0 +1,91 @@
+# Tests compilation and E2E integration with foundry-polkadot, including basic
+# runtime behavior, but not differential runtime correctness.
+
+name: Foundry Integration
+
+on:
+  workflow_call:
+
+env:
+  CARGO_TERM_COLOR: always
+  # Workflow-internal foundry envs are prefixed with `CI_` to not conflict with the
+  # `FOUNDRY_*` namespace, which foundry itself will interpret for its configuration.
+  CI_FOUNDRY_PROJECT_ROOT: tooling-projects/foundry/erc20
+  # This is currently the commit that adds support for resolc ">=0.6.0, <2.0.0".
+  # The latest release as of Apr. 28, 2026 supports ">=0.6.0, <0.7.0".
+  # Once a release includes the updated supported versions, this can be changed to a
+  # tag in order to download the prebuilt binary.
+  CI_FOUNDRY_POLKADOT_COMMIT: b3173d0584382687cc96b2af072d8cb2addf23d3
+
+jobs:
+  use-foundry:
+    runs-on: ubuntu-24.04
+    steps:
+      - name: Checkout revive
+        uses: actions/checkout@v4
+
+      - name: Set Up Rust Toolchain
+        uses: actions-rust-lang/setup-rust-toolchain@v1
+        with:
+          # without this it will override our rust flags
+          rustflags: ""
+          # TODO: Remove once the foundry install step replaces `--commit` with `--install`.
+          # Needed for building foundry-polkadot.
+          target: wasm32-unknown-unknown
+          components: rust-src
+
+      - name: Download resolc Binary
+        uses: actions/download-artifact@v4
+        with:
+          name: resolc-x86_64-unknown-linux-musl
+          path: resolc-bin
+
+      - name: Export resolc Path
+        run: |
+          chmod +x resolc-bin/resolc-x86_64-unknown-linux-musl
+          echo "RESOLC_PATH=$(pwd)/resolc-bin/resolc-x86_64-unknown-linux-musl" >> $GITHUB_ENV
+
+      # TODO: Remove once the foundry install step replaces `--commit` with `--install`.
+      - name: Install Build Dependencies
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y clang libclang-dev build-essential protobuf-compiler
+
+      # NOTE: ~/.foundry/bin is not cached (which would be very useful when using `--commit`)
+      # due to forge sometimes crashing with `Illegal instruction` when using the cached
+      # binaries, seemingly due to the CPU being different when building forge vs running it.
+      - name: Install foundryup-polkadot and the Foundry Toolchain
+        run: |
+          # TODO: Replace `--commit` with `--install` once a release with this commit exists: https://github.com/paritytech/foundry-polkadot/commit/b3173d0584382687cc96b2af072d8cb2addf23d3
+
+          # Pin install path with `FOUNDRY_DIR` to prevent the pre-existing `XDG_CONFIG_HOME` from being used.
+          export FOUNDRY_DIR="$HOME/.foundry"
+          curl -fsSL https://raw.githubusercontent.com/paritytech/foundry-polkadot/refs/heads/master/foundryup/install | bash
+          "$FOUNDRY_DIR/bin/foundryup-polkadot" --commit "$CI_FOUNDRY_POLKADOT_COMMIT"
+
+      - name: Add Foundry to PATH
+        run: echo "$HOME/.foundry/bin" >> "$GITHUB_PATH"
+
+      - name: Check Tool Versions
+        run: |
+          foundryup-polkadot --version
+          forge --version
+
+      - name: Fetch Project Dependencies
+        working-directory: ${{ env.CI_FOUNDRY_PROJECT_ROOT }}
+        run: |
+          mkdir -p lib
+          git clone --depth 1 --branch v1.15.0 https://github.com/foundry-rs/forge-std.git lib/forge-std
+          git clone --depth 1 --branch v5.3.0 https://github.com/OpenZeppelin/openzeppelin-contracts.git lib/openzeppelin-contracts
+
+      - name: Compile Project
+        working-directory: ${{ env.CI_FOUNDRY_PROJECT_ROOT }}
+        run: forge build --use-resolc "$RESOLC_PATH" --optimize -Oz
+
+      - name: Verify Output
+        working-directory: ${{ env.CI_FOUNDRY_PROJECT_ROOT }}
+        run: bash verify-compiler-output.sh "$RESOLC_PATH"
+
+      - name: Test Project
+        working-directory: ${{ env.CI_FOUNDRY_PROJECT_ROOT }}
+        run: forge test --polkadot=pvm --use-resolc "$RESOLC_PATH" --optimize -Oz -vvvv

.github/workflows/test.yml

@@ -65,3 +65,7 @@ jobs:
     # Only run this if `test` successfully completes.
     needs: test
     uses: ./.github/workflows/differential-tests.yml
+
+  run-foundry-tests:
+    needs: run-differential-tests
+    uses: ./.github/workflows/foundry.yml

tooling-projects/foundry/erc20/foundry.toml

@@ -0,0 +1,25 @@
+[profile.default]
+src = "src"
+test = "test"
+libs = ["lib"]
+solc = "0.8.35"
+remappings = [
+    "forge-std/=lib/forge-std/src/",
+    "@openzeppelin/contracts/=lib/openzeppelin-contracts/contracts/",
+]
+extra_output = [
+    "abi",
+    "metadata",
+    "devdoc",
+    "userdoc",
+    "storageLayout",
+    "ir",
+    "irOptimized",
+    "evm.bytecode",
+    "evm.deployedBytecode",
+    "evm.assembly",
+    "evm.methodIdentifiers",
+]
+
+[profile.default.polkadot]
+resolc_compile = true

tooling-projects/foundry/erc20/src/MyToken.sol

@@ -0,0 +1,17 @@
+// SPDX-License-Identifier: MIT
+// Compatible with OpenZeppelin Contracts ^5.0.0
+pragma solidity ^0.8.22;
+
+import { ERC20 }   from "@openzeppelin/contracts/token/ERC20/ERC20.sol";
+import { Ownable } from "@openzeppelin/contracts/access/Ownable.sol";
+
+contract MyToken is ERC20, Ownable {
+    constructor(address initialOwner)
+        ERC20("MyToken", "MTK")
+        Ownable(initialOwner)
+    {}
+
+    function mint(address to, uint256 amount) public onlyOwner {
+        _mint(to, amount);
+    }
+}

tooling-projects/foundry/erc20/test/MyToken.t.sol

@@ -0,0 +1,61 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.22;
+
+import { Test } from "forge-std/Test.sol";
+import { Ownable } from "@openzeppelin/contracts/access/Ownable.sol";
+import { MyToken } from "../src/MyToken.sol";
+
+contract MyTokenTest is Test {
+    MyToken internal token;
+    address internal owner = address(this);
+    address internal alice = address(0xA11CE);
+    address internal bob   = address(0xB0B);
+
+    function setUp() public {
+        token = new MyToken(owner);
+    }
+
+    function test_NameAndSymbol() public view {
+        assertEq(token.name(), "MyToken");
+        assertEq(token.symbol(), "MTK");
+    }
+
+    function test_Owner() public view {
+        assertEq(token.owner(), owner);
+    }
+
+    function test_OwnerCanMint() public {
+        token.mint(alice, 1000);
+        assertEq(token.balanceOf(alice), 1000);
+    }
+
+    function test_NonOwnerCannotMint() public {
+        vm.prank(alice);
+        vm.expectRevert(
+            abi.encodeWithSelector(Ownable.OwnableUnauthorizedAccount.selector, alice)
+        );
+        token.mint(alice, 1000);
+    }
+
+    function test_TotalSupplyIncreases() public {
+        uint256 before = token.totalSupply();
+        token.mint(alice, 500);
+        assertEq(token.totalSupply() - before, 500);
+    }
+
+    function test_Transfer() public {
+        token.mint(owner, 1000);
+        assertTrue(token.transfer(alice, 100));
+        assertEq(token.balanceOf(alice), 100);
+        assertEq(token.balanceOf(owner), 900);
+    }
+
+    function test_TransferFrom() public {
+        token.mint(owner, 1000);
+        token.approve(alice, 50);
+        vm.prank(alice);
+        assertTrue(token.transferFrom(owner, bob, 50));
+        assertEq(token.balanceOf(bob), 50);
+        assertEq(token.allowance(owner, alice), 0);
+    }
+}

tooling-projects/foundry/erc20/verify-compiler-output.sh

@@ -0,0 +1,33 @@
+#!/usr/bin/env bash
+
+# Asserts that the compiled project contains the expected compiler output.
+# Requires `forge` in PATH. Run from the project's root.
+#
+# Usage: verify-compiler-output.sh <resolc-path>
+
+set -euxo pipefail
+
+if [[ $# -ne 1 ]]; then
+    echo "usage: $(basename "$0") <resolc-path>" >&2
+    exit 2
+fi
+
+resolc=$1
+
+inspect() {
+    forge inspect --use-resolc "$resolc" MyToken "$@"
+}
+
+inspect bytecode          | grep '^0x50564d'                      > /dev/null
+inspect deployedBytecode  | grep '^0x50564d'                      > /dev/null
+inspect irOptimized       | grep .                                > /dev/null
+inspect ir                | grep .                                > /dev/null
+inspect assembly          | grep .                                > /dev/null
+inspect abi               --json | jq -e 'length > 0'             > /dev/null
+inspect methodIdentifiers --json | jq -e 'length > 0'             > /dev/null
+inspect storageLayout     --json | jq -e '.storage | length > 0'  > /dev/null
+inspect metadata          --json | jq -e 'length > 0'             > /dev/null
+inspect devdoc            --json | jq -e 'length > 0'             > /dev/null
+inspect userdoc           --json | jq -e 'length > 0'             > /dev/null
+
+echo "all checks passed"