RelativePathsRule for #9

README.md

@@ -58,6 +58,7 @@ opt_in_rules:
 disabled_rules:
   - build_files_ordered       # checks that the ordering of techincally-unordered collections Xcode writes out is preserved
   - validate_build_settings   # checks that build settings have valid values
+  - relative_paths            # checks for any absolute file references
 ```
 
 ## Alternatives

Sources/XCLinting/Rules/RelativePathsRule.swift

@@ -0,0 +1,39 @@
+import Foundation
+
+import XcodeProj
+
+/// Make sure all file references use relative paths.
+struct RelativePathsRule {
+	func run(_ environment: XCLinter.Environment) throws -> [Violation] {
+		var violations = [Violation]()
+
+		// check top-level
+		for project in environment.project.pbxproj.projects {
+			guard let group = project.mainGroup else { continue }
+
+			violations.append(contentsOf: checkGroup(group))
+		}
+
+		return violations
+	}
+
+	private func checkGroup(_ group: PBXGroup) -> [Violation] {
+		var violations = [Violation]()
+
+		let groupName = group.name ?? group.path ?? "???"
+
+		for element in group.children {
+			let elementName = element.name ?? element.path ?? "???"
+
+			if element.path?.starts(with: "/") == true {
+				violations.append(.init("\(groupName):\(elementName) has an absolute file path"))
+			}
+
+			if let subgroup = element as? PBXGroup {
+				violations.append(contentsOf: checkGroup(subgroup))
+			}
+		}
+
+		return violations
+	}
+}

Sources/XCLinting/XCLinter.swift

@@ -68,6 +68,7 @@ extension XCLinter {
 	public static let defaultRuleIdentifiers: Set<String> = [
 		"build_files_ordered",
 		"validate_build_settings",
+		"relative_paths",
 	]
 
 	public static let defaultRules: [Rule] = Array(ruleMap.filter({ defaultRuleIdentifiers.contains($0.0) }).values)
@@ -81,6 +82,7 @@ extension XCLinter {
 		"implicit_dependencies": { try ImplicitDependenciesRule().run($0) },
 		"targets_use_xcconfig": { try TargetsUseXCConfigRule().run($0) },
 		"projects_use_xcconfig": { try ProjectsUseXCConfigRule().run($0) },
-		"shared_scheme_skips_tests": { try SharedSchemeSkipsTestsRule().run($0) }
+		"shared_scheme_skips_tests": { try SharedSchemeSkipsTestsRule().run($0) },
+		"relative_paths": { try RelativePathsRule().run($0) },
 	]
 }

Tests/XCLintTests/RelativePathsRuleTests.swift

@@ -0,0 +1,39 @@
+import XCTest
+
+@testable import XCLinting
+import XcodeProj
+
+final class RelativePathsRuleTests: XCTestCase {
+	func testProjectWithOnlyRelativePaths() throws {
+		let url = try Bundle.module.testDataURL(named: "StockMacOSApp.xcodeproj")
+
+		let project = try XcodeProj(pathString: url.path)
+
+		let env = XCLinter.Environment(
+			project: project,
+			projectRootURL: url,
+			configuration: Configuration()
+		)
+
+		let violations = try RelativePathsRule().run(env)
+
+		XCTAssertTrue(violations.isEmpty)
+	}
+
+	func testProjectWithOneAbosluteFilePath() throws {
+		let url = try Bundle.module.testDataURL(named: "AbsolueFileReference.xcodeproj")
+
+		let project = try XcodeProj(pathString: url.path)
+
+		let env = XCLinter.Environment(
+			project: project,
+			projectRootURL: url,
+			configuration: Configuration()
+		)
+
+		let violations = try RelativePathsRule().run(env)
+
+		XCTAssertFalse(violations.isEmpty)
+	}
+}
+