feat(ct): add checks for unused imports

packages/contracts-bedrock/justfile

@@ -84,10 +84,6 @@ gas-snapshot-no-build:
 # Generates a gas snapshot.
 gas-snapshot: build-go-ffi gas-snapshot-no-build
 
-# Checks that the state diff is up to date.
-statediff:
-  ./scripts/utils/statediff.sh && git diff --exit-code
-
 # Generates default Kontrol summary.
 kontrol-summary:
   ./test/kontrol/scripts/make-summary-deployment.sh
@@ -176,6 +172,13 @@ lint-forge-tests-check:
 lint-check:
   forge fmt --check
 
+# Checks for unused imports in Solidity contracts. Does not build contracts.
+unused-imports-check-no-build:
+  go run ./scripts/checks/unused-imports
+
+# Checks for unused imports in Solidity contracts.
+unused-imports-check: build unused-imports-check-no-build
+
 # Checks that the deploy configs are valid.
 validate-deploy-configs:
   ./scripts/checks/check-deploy-configs.sh
@@ -189,8 +192,17 @@ validate-spacers: build validate-spacers-no-build
 
 # TODO: Also run lint-forge-tests-check but we need to fix the test names first.
 # Runs all checks.
-check: gas-snapshot-check-no-build kontrol-deployment-check snapshots-check-no-build lint-check semver-diff-check-no-build semver-natspec-check-no-build validate-deploy-configs validate-spacers-no-build interfaces-check-no-build
-
+check:
+  @just gas-snapshot-check-no-build \
+  unused-imports-check-no-build \
+  kontrol-deployment-check \
+  snapshots-check-no-build \
+  lint-check \
+  semver-diff-check-no-build \
+  semver-natspec-check-no-build \
+  validate-deploy-configs \
+  validate-spacers-no-build \
+  interfaces-check-no-build
 
 ########################################################
 #                      DEV TOOLS                       #

packages/contracts-bedrock/scripts/Artifacts.s.sol

@@ -4,7 +4,6 @@ pragma solidity ^0.8.0;
 import { console2 as console } from "forge-std/console2.sol";
 import { stdJson } from "forge-std/StdJson.sol";
 import { Vm } from "forge-std/Vm.sol";
-import { Executables } from "scripts/libraries/Executables.sol";
 import { Predeploys } from "src/libraries/Predeploys.sol";
 import { Config } from "scripts/libraries/Config.sol";
 import { StorageSlot } from "scripts/libraries/ForgeArtifacts.sol";

packages/contracts-bedrock/scripts/DeployOPChain.s.sol

@@ -25,7 +25,7 @@ import { IDisputeGameFactory } from "src/dispute/interfaces/IDisputeGameFactory.
 import { IAnchorStateRegistry } from "src/dispute/interfaces/IAnchorStateRegistry.sol";
 import { IFaultDisputeGame } from "src/dispute/interfaces/IFaultDisputeGame.sol";
 import { IPermissionedDisputeGame } from "src/dispute/interfaces/IPermissionedDisputeGame.sol";
-import { Claim, Duration, GameType, GameTypes, Hash, OutputRoot } from "src/dispute/lib/Types.sol";
+import { Claim, Duration, GameType, GameTypes, Hash } from "src/dispute/lib/Types.sol";
 
 import { OPContractsManager } from "src/L1/OPContractsManager.sol";
 import { IOptimismPortal2 } from "src/L1/interfaces/IOptimismPortal2.sol";

packages/contracts-bedrock/scripts/L2Genesis.s.sol

@@ -2,15 +2,12 @@
 pragma solidity 0.8.15;
 
 // Testing
-import { Script } from "forge-std/Script.sol";
 import { console2 as console } from "forge-std/console2.sol";
 import { EIP1967Helper } from "test/mocks/EIP1967Helper.sol";
 
 // Scripts
 import { Deployer } from "scripts/deploy/Deployer.sol";
 import { Config, OutputMode, OutputModeUtils, Fork, ForkUtils, LATEST_FORK } from "scripts/libraries/Config.sol";
-import { Artifacts } from "scripts/Artifacts.s.sol";
-import { DeployConfig } from "scripts/deploy/DeployConfig.s.sol";
 import { Process } from "scripts/libraries/Process.sol";
 import { SetPreinstalls } from "scripts/SetPreinstalls.s.sol";
 

packages/contracts-bedrock/scripts/checks/unused-imports/main.go

@@ -0,0 +1,149 @@
+package main
+
+import (
+	"bufio"
+	"errors"
+	"fmt"
+	"os"
+	"path/filepath"
+	"regexp"
+	"runtime"
+	"strings"
+	"sync"
+	"sync/atomic"
+)
+
+var importPattern = regexp.MustCompile(`import\s*{([^}]+)}`)
+var asPattern = regexp.MustCompile(`(\S+)\s+as\s+(\S+)`)
+
+func main() {
+	if err := run(); err != nil {
+		writeStderr("an error occurred: %v", err)
+		os.Exit(1)
+	}
+}
+
+func writeStderr(msg string, args ...any) {
+	_, _ = fmt.Fprintf(os.Stderr, msg+"\n", args...)
+}
+
+func run() error {
+	cwd, err := os.Getwd()
+	if err != nil {
+		return fmt.Errorf("failed to get current working directory: %w", err)
+	}
+
+	var hasErr int32
+	var outMtx sync.Mutex
+	fail := func(msg string, args ...any) {
+		outMtx.Lock()
+		writeStderr("❌  "+msg, args...)
+		outMtx.Unlock()
+		atomic.StoreInt32(&hasErr, 1)
+	}
+
+	dirs := []string{"src", "scripts", "test"}
+	sem := make(chan struct{}, runtime.NumCPU())
+
+	for _, dir := range dirs {
+		dirPath := filepath.Join(cwd, dir)
+		if _, err := os.Stat(dirPath); errors.Is(err, os.ErrNotExist) {
+			continue
+		}
+
+		err := filepath.Walk(dirPath, func(path string, info os.FileInfo, err error) error {
+			if err != nil {
+				return err
+			}
+			if !info.IsDir() && strings.HasSuffix(info.Name(), ".sol") {
+				sem <- struct{}{}
+				go func() {
+					defer func() { <-sem }()
+					processFile(path, fail)
+				}()
+			}
+			return nil
+		})
+
+		if err != nil {
+			return fmt.Errorf("failed to walk directory %s: %w", dir, err)
+		}
+	}
+
+	for i := 0; i < cap(sem); i++ {
+		sem <- struct{}{}
+	}
+
+	if atomic.LoadInt32(&hasErr) == 1 {
+		return errors.New("unused imports check failed, see logs above")
+	}
+
+	return nil
+}
+
+func processFile(filePath string, fail func(string, ...any)) {
+	content, err := os.ReadFile(filePath)
+	if err != nil {
+		fail("%s: failed to read file: %v", filePath, err)
+		return
+	}
+
+	imports := findImports(string(content))
+	unusedImports := checkUnusedImports(imports, string(content))
+
+	if len(unusedImports) > 0 {
+		fail("File: %s\nUnused imports:", filePath)
+		for _, unused := range unusedImports {
+			fail("  - %s", unused)
+		}
+	}
+}
+
+func findImports(content string) []string {
+	var imports []string
+	matches := importPattern.FindAllStringSubmatch(content, -1)
+	for _, match := range matches {
+		if len(match) > 1 {
+			importList := strings.Split(match[1], ",")
+			for _, imp := range importList {
+				imports = append(imports, strings.TrimSpace(imp))
+			}
+		}
+	}
+	return imports
+}
+
+func checkUnusedImports(imports []string, content string) []string {
+	var unusedImports []string
+	for _, imp := range imports {
+		searchTerm := imp
+		displayName := imp
+
+		if match := asPattern.FindStringSubmatch(imp); len(match) > 2 {
+			searchTerm = match[2]
+			displayName = fmt.Sprintf("%s as %s", match[1], match[2])
+		}
+
+		if !isImportUsed(searchTerm, content) {
+			unusedImports = append(unusedImports, displayName)
+		}
+	}
+	return unusedImports
+}
+
+func isImportUsed(imp, content string) bool {
+	scanner := bufio.NewScanner(strings.NewReader(content))
+	for scanner.Scan() {
+		line := scanner.Text()
+		if strings.HasPrefix(strings.TrimSpace(line), "//") {
+			continue
+		}
+		if strings.Contains(line, "import") {
+			continue
+		}
+		if strings.Contains(line, imp) {
+			return true
+		}
+	}
+	return false
+}

packages/contracts-bedrock/scripts/deploy/ChainAssertions.sol

@@ -7,8 +7,6 @@ import { console2 as console } from "forge-std/console2.sol";
 
 // Scripts
 import { DeployConfig } from "scripts/deploy/DeployConfig.s.sol";
-import { Deployer } from "scripts/deploy/Deployer.sol";
-import { ISystemConfigV0 } from "scripts/interfaces/ISystemConfigV0.sol";
 import { ISystemConfigInterop } from "src/L1/interfaces/ISystemConfigInterop.sol";
 
 // Libraries

packages/contracts-bedrock/scripts/deploy/Deploy.s.sol

@@ -3,7 +3,6 @@ pragma solidity ^0.8.0;
 
 // Testing
 import { VmSafe } from "forge-std/Vm.sol";
-import { Script } from "forge-std/Script.sol";
 import { console2 as console } from "forge-std/console2.sol";
 import { stdJson } from "forge-std/StdJson.sol";
 import { AlphabetVM } from "test/mocks/AlphabetVM.sol";
@@ -40,17 +39,15 @@ import { IProxy } from "src/universal/interfaces/IProxy.sol";
 import { IProxyAdmin } from "src/universal/interfaces/IProxyAdmin.sol";
 import { IOptimismPortal } from "src/L1/interfaces/IOptimismPortal.sol";
 import { IOptimismPortal2 } from "src/L1/interfaces/IOptimismPortal2.sol";
-import { IOptimismPortalInterop } from "src/L1/interfaces/IOptimismPortalInterop.sol";
 import { ICrossDomainMessenger } from "src/universal/interfaces/ICrossDomainMessenger.sol";
 import { IL1CrossDomainMessenger } from "src/L1/interfaces/IL1CrossDomainMessenger.sol";
 import { IL2OutputOracle } from "src/L1/interfaces/IL2OutputOracle.sol";
 import { ISuperchainConfig } from "src/L1/interfaces/ISuperchainConfig.sol";
 import { ISystemConfig } from "src/L1/interfaces/ISystemConfig.sol";
-import { ISystemConfigInterop } from "src/L1/interfaces/ISystemConfigInterop.sol";
 import { IDataAvailabilityChallenge } from "src/L1/interfaces/IDataAvailabilityChallenge.sol";
 import { IL1ERC721Bridge } from "src/L1/interfaces/IL1ERC721Bridge.sol";
 import { IL1StandardBridge } from "src/L1/interfaces/IL1StandardBridge.sol";
-import { IProtocolVersions, ProtocolVersion } from "src/L1/interfaces/IProtocolVersions.sol";
+import { ProtocolVersion } from "src/L1/interfaces/IProtocolVersions.sol";
 import { IBigStepper } from "src/dispute/interfaces/IBigStepper.sol";
 import { IDisputeGameFactory } from "src/dispute/interfaces/IDisputeGameFactory.sol";
 import { IDisputeGame } from "src/dispute/interfaces/IDisputeGame.sol";

packages/contracts-bedrock/scripts/deploy/DeployConfig.s.sol

@@ -6,7 +6,6 @@ import { console2 as console } from "forge-std/console2.sol";
 import { stdJson } from "forge-std/StdJson.sol";
 import { Executables } from "scripts/libraries/Executables.sol";
 import { Process } from "scripts/libraries/Process.sol";
-import { Chains } from "scripts/libraries/Chains.sol";
 import { Config, Fork, ForkUtils } from "scripts/libraries/Config.sol";
 
 /// @title DeployConfig

packages/contracts-bedrock/scripts/deploy/DeployOwnership.s.sol

@@ -2,7 +2,6 @@
 pragma solidity ^0.8.0;
 
 import { console2 as console } from "forge-std/console2.sol";
-import { stdJson } from "forge-std/StdJson.sol";
 
 import { GnosisSafe as Safe } from "safe-contracts/GnosisSafe.sol";
 import { GnosisSafeProxyFactory as SafeProxyFactory } from "safe-contracts/proxies/GnosisSafeProxyFactory.sol";