Introduce guarded filepath provider for file collection (#6435)

.github/workflows/test.yml

@@ -38,6 +38,7 @@ jobs:
     name: SPM, macOS ${{ matrix.macOS }}, Xcode ${{ matrix.xcode }}
     runs-on: macos-${{ matrix.macOS }}
     strategy:
+      fail-fast: false
       matrix:
         include:
           - macOS: '14'

.gitignore

@@ -39,7 +39,7 @@ default.profraw
 
 SwiftLint.xcodeproj
 SwiftLint.pkg
-*.zip
+/*.zip
 benchmark_*
 docs/
 rule_docs/
@@ -73,4 +73,4 @@ oss-check-summary.md
 
 
 # VS Code
-.vscode
+.vscode

CHANGELOG.md

@@ -20,6 +20,11 @@
   [SimplyDanny](https://github.com/SimplyDanny)
   [#6423](https://github.com/realm/SwiftLint/issues/6423)
 
+* Inform users about files being skipped due to impossible file system representation
+  instead of crashing.  
+  [SimplyDanny](https://github.com/SimplyDanny)
+  [#6419](https://github.com/realm/SwiftLint/issues/6419)
+
 * Ignore `override` functions in `async_without_await` rule.  
   [SimplyDanny](https://github.com/SimplyDanny)
   [#6416](https://github.com/realm/SwiftLint/issues/6416)

Package.swift

@@ -203,6 +203,7 @@ let package = Package(
         .testTarget(
             name: "IntegrationTests",
             dependencies: [
+                "SwiftLintCore",
                 "SwiftLintFramework",
                 "TestHelpers",
             ],

Source/SwiftLintCore/Extensions/URL+SwiftLint.swift

@@ -5,6 +5,18 @@ public extension URL {
         withUnsafeFileSystemRepresentation { String(cString: $0!) }
     }
 
+    var filepathGuarded: String? {
+        withUnsafeFileSystemRepresentation { ptr in
+            guard let ptr else {
+                Issue.genericError(
+                    "File with URL '\(self)' cannot be represented as a file system path; skipping it"
+                ).print()
+                return nil
+            }
+            return String(cString: ptr)
+        }
+    }
+
     var isSwiftFile: Bool {
         filepath.isFile && pathExtension == "swift"
     }

Source/SwiftLintFramework/Extensions/FileManager+SwiftLint.swift

@@ -71,7 +71,7 @@ extension FileManager: LintableFileManager, @unchecked @retroactive Sendable {
     }
 
     private func collectFiles(atPath absolutePath: URL, excluder: Excluder) -> [String] {
-        guard let enumerator = enumerator(atPath: absolutePath.filepath) else {
+        guard let root = absolutePath.filepathGuarded, let enumerator = enumerator(atPath: root) else {
             return []
         }
 
@@ -80,7 +80,9 @@ extension FileManager: LintableFileManager, @unchecked @retroactive Sendable {
 
         while let element = enumerator.nextObject() as? String {
             let absoluteElementPath = URL(fileURLWithPath: element, relativeTo: absolutePath)
-            let absoluteStandardizedElementPath = absoluteElementPath.standardized.filepath
+            guard let absoluteStandardizedElementPath = absoluteElementPath.standardized.filepathGuarded else {
+                continue
+            }
             if absoluteElementPath.path.isFile {
                 if absoluteElementPath.pathExtension == "swift",
                    !excluder.excludes(path: absoluteStandardizedElementPath) {

Tests/IntegrationTests/ConfigPathResolutionTests.swift

@@ -3,7 +3,9 @@ import SwiftLintFramework
 import TestHelpers
 import XCTest
 
-final class ConfigPathResolutionTests: SwiftLintTestCase {
+@testable import SwiftLintCore
+
+final class ConfigPathResolutionTests: SwiftLintTestCase, @unchecked Sendable {
     private func fixturePath(_ scenario: String) -> URL {
         URL(fileURLWithPath: #filePath)
             .deletingLastPathComponent()
@@ -16,10 +18,8 @@ final class ConfigPathResolutionTests: SwiftLintTestCase {
         let scenarioPath = fixturePath(scenario).filepath
 
         let previousDir = FileManager.default.currentDirectoryPath
-        defer {
-            _ = FileManager.default.changeCurrentDirectoryPath(previousDir)
-        }
         XCTAssert(FileManager.default.changeCurrentDirectoryPath(scenarioPath))
+        defer { _ = FileManager.default.changeCurrentDirectoryPath(previousDir) }
 
         let config = Configuration(configurationFiles: configFile.map { [$0] } ?? [])
         let files = config.lintableFiles(
@@ -169,4 +169,36 @@ final class ConfigPathResolutionTests: SwiftLintTestCase {
                 .contains("explicit_type_interface")
         )
     }
+
+    #if !os(Windows)
+    func testUnicodePrivateUseAreaCharacterInPath() async throws {
+        let fixture = fixturePath("_8_unicode_private_use_area")
+
+        let process = Process()
+        process.executableURL = URL(filePath: "/usr/bin/env", directoryHint: .notDirectory)
+        process.arguments = ["unzip", "-o", fixture.appending(path: "app.zip").filepath, "-d", fixture.filepath]
+        try process.run()
+        process.waitUntilExit()
+        defer { try? FileManager.default.removeItem(at: fixture.appending(path: "App")) }
+
+        if #available(macOS 26, *) {
+            XCTAssertEqual(
+                lintableFilePaths(in: "_8_unicode_private_use_area/App"),
+                ["Resources/Settings.bundle/androidx.core:core-bundle.swift"]
+            )
+        } else {
+            let console = await Issue.captureConsole {
+                XCTAssert(lintableFilePaths(in: "_8_unicode_private_use_area/App").isEmpty)
+            }
+            XCTAssert(
+                console.contains(
+                    """
+                    error: File with URL 'androidx.core:core-bundle.swift' \
+                    cannot be represented as a file system path; skipping it
+                    """
+                )
+            )
+        }
+    }
+    #endif
 }