Scheme-first search for shared scheme targets

Sources/XCLinting/Rules/SharedSchemesRule.swift

@@ -0,0 +1,48 @@
+import Foundation
+
+import XcodeProj
+import XCConfig
+
+/// Ensure that targets have a shared scheme on disk.
+struct SharedSchemesRule {
+	func run(_ environment: XCLinter.Environment) throws -> [Violation] {
+		let sharedSchemesURL = environment
+			.projectRootURL
+			.appendingPathComponent("xcshareddata/xcschemes", isDirectory: true)
+			.standardizedFileURL
+
+		let fileManager = FileManager.default
+
+		guard fileManager.isReadableFile(atPath: sharedSchemesURL.path) else {
+			return [.init("Shared scheme directory not found")]
+		}
+
+		let targetNames = environment.project.pbxproj.projects.flatMap { $0.targets }.map { $0.name }
+		var targetNameSet = Set(targetNames)
+
+		for entry in try fileManager.contentsOfDirectory(atPath: sharedSchemesURL.path) {
+			let entryPath = sharedSchemesURL
+				.appendingPathComponent(entry, isDirectory: false)
+				.standardizedFileURL
+				.path
+
+			let scheme = try XCScheme(pathString: entryPath)
+
+			for entry in scheme.buildAction?.buildActionEntries ?? [] {
+				let name = entry.buildableReference.blueprintName
+
+				targetNameSet.remove(name)
+			}
+
+			for entry in scheme.testAction?.testables ?? [] {
+				let name = entry.buildableReference.blueprintName
+
+				targetNameSet.remove(name)
+			}
+		}
+
+		return targetNameSet.map { name in
+			Violation("No shared scheme found that references \(name)")
+		}
+	}
+}

Tests/XCLintTests/SharedSchemesRuleTests.swift

@@ -21,7 +21,7 @@ final class SharedSchemesRuleTests: XCTestCase {
 	}
 
 	func testProjectWithMissingSharedSchemes() throws {
-		let url = try Bundle.module.testDataURL(named: "SchemeSkipsTests.xcodeproj")
+		let url = try Bundle.module.testDataURL(named: "BuildFilesOutOfOrder.xcodeproj")
 
 		let project = try XcodeProj(pathString: url.path)