added support for scanning image assets

README.md

@@ -480,6 +480,9 @@ Periphery can analyze projects using other build systems, though it cannot drive
     "plists": [
         "path/to/file.plist"
     ],
+    "asset_catalogs": [
+        "path/to/Assets.xcassets"
+    ],
     "xibs": [
         "path/to/file.xib",
         "path/to/file.storyboard"

Sources/BUILD.bazel

@@ -25,6 +25,7 @@ swift_library(
     srcs = [
         "SyntaxAnalysis/CommentCommand.swift",
         "SyntaxAnalysis/DeclarationSyntaxVisitor.swift",
+        "SyntaxAnalysis/ImageAssetReferenceSyntaxVisitor.swift",
         "SyntaxAnalysis/ImportSyntaxVisitor.swift",
         "SyntaxAnalysis/MultiplexingSyntaxVisitor.swift",
         "SyntaxAnalysis/SourceLOCCounter.swift",
@@ -52,6 +53,7 @@ swift_library(
         "SourceGraph/Elements/Declaration.swift",
         "SourceGraph/Elements/DeclarationAttribute.swift",
         "SourceGraph/Elements/ImportStatement.swift",
+        "SourceGraph/Elements/ImageAssetReference.swift",
         "SourceGraph/Elements/Location.swift",
         "SourceGraph/Elements/ProjectFileKind.swift",
         "SourceGraph/Elements/Reference.swift",
@@ -74,6 +76,7 @@ swift_library(
         "SourceGraph/Mutators/GenericClassAndStructConstructorReferenceBuilder.swift",
         "SourceGraph/Mutators/InheritedImplicitInitializerReferenceBuilder.swift",
         "SourceGraph/Mutators/InterfaceBuilderPropertyRetainer.swift",
+        "SourceGraph/Mutators/ImageAssetReferenceRetainer.swift",
         "SourceGraph/Mutators/ObjCAccessibleRetainer.swift",
         "SourceGraph/Mutators/PropertyWrapperRetainer.swift",
         "SourceGraph/Mutators/ProtocolConformanceReferenceBuilder.swift",
@@ -195,6 +198,8 @@ swift_library(
 swift_library(
     name = "Indexer",
     srcs = [
+        "Indexer/AssetCatalogIndexer.swift",
+        "Indexer/AssetCatalogParser.swift",
         "Indexer/IndexPipeline.swift",
         "Indexer/IndexPlan.swift",
         "Indexer/Indexer.swift",

Sources/Indexer/AssetCatalogIndexer.swift

@@ -0,0 +1,36 @@
+import Configuration
+import Logger
+import Shared
+import SourceGraph
+import SystemPackage
+
+final class AssetCatalogIndexer: Indexer {
+    private let assetCatalogs: Set<FilePath>
+    private let graph: SourceGraphMutex
+    private let logger: ContextualLogger
+
+    required init(assetCatalogs: Set<FilePath>, graph: SourceGraphMutex, logger: ContextualLogger, configuration: Configuration) {
+        self.assetCatalogs = assetCatalogs
+        self.graph = graph
+        self.logger = logger.contextualized(with: "asset-catalog")
+        super.init(configuration: configuration)
+    }
+
+    func perform() throws {
+        let (includedFiles, excludedFiles) = filterIndexExcluded(from: assetCatalogs)
+        excludedFiles.forEach { self.logger.debug("Excluding \($0.string)") }
+
+        try JobPool(jobs: Array(includedFiles)).forEach { [weak self] assetCatalog in
+            guard let self else { return }
+
+            let elapsed = Benchmark.measure {
+                let imageAssets = AssetCatalogParser(path: assetCatalog).parse()
+                self.graph.withLock { graph in
+                    imageAssets.forEach { graph.addImageAsset($0) }
+                }
+            }
+
+            logger.debug("\(assetCatalog.string) (\(elapsed)s)")
+        }
+    }
+}

Sources/Indexer/AssetCatalogParser.swift

@@ -0,0 +1,44 @@
+import Foundation
+import SourceGraph
+import SystemPackage
+
+final class AssetCatalogParser {
+    private let path: FilePath
+
+    required init(path: FilePath) {
+        self.path = path
+    }
+
+    func parse() -> Set<Declaration> {
+        guard let enumerator = FileManager.default.enumerator(
+            at: path.url,
+            includingPropertiesForKeys: [.isDirectoryKey],
+            options: [.skipsHiddenFiles]
+        ) else { return [] }
+
+        var declarations = Set<Declaration>()
+
+        for case let url as URL in enumerator {
+            guard url.pathExtension == "imageset" else { continue }
+
+            let imageSetPath = FilePath(url.path)
+            let name = url.deletingPathExtension().lastPathComponent
+            let contentsPath = imageSetPath.appending("Contents.json")
+            let locationPath = FileManager.default.fileExists(atPath: contentsPath.lexicallyNormalized().string) ? contentsPath : imageSetPath
+            let locationFile = SourceFile(path: locationPath, modules: [])
+            let location = Location(file: locationFile, line: 1, column: 1)
+            let usr = "image-asset-\(imageSetPath.lexicallyNormalized().string)"
+
+            declarations.insert(
+                Declaration(
+                    name: name,
+                    kind: .imageAsset,
+                    usrs: [usr],
+                    location: location
+                )
+            )
+        }
+
+        return declarations
+    }
+}

Sources/Indexer/IndexPipeline.swift

@@ -28,6 +28,15 @@ public struct IndexPipeline {
             swiftVersion: swiftVersion
         ).perform()
 
+        if !plan.assetCatalogPaths.isEmpty {
+            try AssetCatalogIndexer(
+                assetCatalogs: plan.assetCatalogPaths,
+                graph: graph,
+                logger: logger,
+                configuration: configuration
+            ).perform()
+        }
+
         if !plan.plistPaths.isEmpty {
             try InfoPlistIndexer(
                 infoPlistFiles: plan.plistPaths,

Sources/Indexer/IndexPlan.swift

@@ -4,19 +4,22 @@ import SystemPackage
 
 public struct IndexPlan {
     public let sourceFiles: [SourceFile: [IndexUnit]]
+    public let assetCatalogPaths: Set<FilePath>
     public let plistPaths: Set<FilePath>
     public let xibPaths: Set<FilePath>
     public let xcDataModelPaths: Set<FilePath>
     public let xcMappingModelPaths: Set<FilePath>
 
     public init(
         sourceFiles: [SourceFile: [IndexUnit]],
+        assetCatalogPaths: Set<FilePath> = [],
         plistPaths: Set<FilePath> = [],
         xibPaths: Set<FilePath> = [],
         xcDataModelPaths: Set<FilePath> = [],
         xcMappingModelPaths: Set<FilePath> = []
     ) {
         self.sourceFiles = sourceFiles
+        self.assetCatalogPaths = assetCatalogPaths
         self.plistPaths = plistPaths
         self.xibPaths = xibPaths
         self.xcDataModelPaths = xcDataModelPaths

Sources/Indexer/SwiftIndexer.swift

@@ -260,6 +260,7 @@ final class SwiftIndexer: Indexer {
             let multiplexingSyntaxVisitor = try MultiplexingSyntaxVisitor(file: sourceFile, swiftVersion: swiftVersion)
             let declarationSyntaxVisitor = multiplexingSyntaxVisitor.add(DeclarationSyntaxVisitor.self)
             let importSyntaxVisitor = multiplexingSyntaxVisitor.add(ImportSyntaxVisitor.self)
+            let imageAssetReferenceSyntaxVisitor = multiplexingSyntaxVisitor.add(ImageAssetReferenceSyntaxVisitor.self)
 
             multiplexingSyntaxVisitor.visit()
 
@@ -279,6 +280,10 @@ final class SwiftIndexer: Indexer {
                 }
             }
 
+            graph.withLock { graph in
+                imageAssetReferenceSyntaxVisitor.references.forEach { graph.add($0) }
+            }
+
             associateLatentReferences()
             associateDanglingReferences()
             visitDeclarations(using: declarationSyntaxVisitor)

Sources/Indexer/XibIndexer.swift

@@ -29,10 +29,11 @@ final class XibIndexer: Indexer {
 
             let elapsed = try Benchmark.measure {
                 do {
-                    let refs = try XibParser(path: xibPath)
+                    let result = try XibParser(path: xibPath)
                         .parse()
                     self.graph.withLock { graph in
-                        refs.forEach { graph.add($0) }
+                        result.assetReferences.forEach { graph.add($0) }
+                        result.imageAssetReferences.forEach { graph.add($0) }
                     }
                 } catch {
                     throw XibError.failedToParse(path: xibPath, underlyingError: error)

Sources/Indexer/XibParser.swift

@@ -10,8 +10,15 @@ final class XibParser {
         self.path = path
     }
 
-    func parse() throws -> [AssetReference] {
-        guard let data = FileManager.default.contents(atPath: path.string) else { return [] }
+    struct Result {
+        let assetReferences: [AssetReference]
+        let imageAssetReferences: Set<ImageAssetReference>
+    }
+
+    func parse() throws -> Result {
+        guard let data = FileManager.default.contents(atPath: path.string) else {
+            return Result(assetReferences: [], imageAssetReferences: [])
+        }
 
         let structure = try AEXMLDocument(xml: data)
 
@@ -22,8 +29,10 @@ final class XibParser {
         // Collect all references with their outlets, actions, and runtime attributes
         var referencesByClass: [String: (outlets: Set<String>, actions: Set<String>, runtimeAttributes: Set<String>)] = [:]
         collectReferences(from: structure.root, idToCustomClass: idToCustomClass, into: &referencesByClass)
+        var imageReferences: Set<ImageAssetReference> = []
+        collectImageReferences(from: structure.root, into: &imageReferences)
 
-        return referencesByClass.map { className, members in
+        let assetReferences = referencesByClass.map { className, members in
             AssetReference(
                 absoluteName: className,
                 source: .interfaceBuilder,
@@ -32,6 +41,8 @@ final class XibParser {
                 runtimeAttributes: Array(members.runtimeAttributes)
             )
         }
+
+        return Result(assetReferences: assetReferences, imageAssetReferences: imageReferences)
     }
 
     // MARK: - Private
@@ -180,4 +191,31 @@ final class XibParser {
 
         return path
     }
+
+    private func collectImageReferences(from element: AEXMLElement, into imageReferences: inout Set<ImageAssetReference>) {
+        for (key, value) in element.attributes {
+            let lowercasedKey = key.lowercased()
+
+            if lowercasedKey.contains("image"), lowercasedKey != "systemimage" {
+                imageReferences.insert(imageReference(named: value))
+            }
+        }
+
+        if element.name == "image", let name = element.attributes["name"] {
+            imageReferences.insert(imageReference(named: name))
+        }
+
+        for child in element.children {
+            collectImageReferences(from: child, into: &imageReferences)
+        }
+    }
+
+    private func imageReference(named name: String) -> ImageAssetReference {
+        let file = SourceFile(path: path, modules: [])
+        return ImageAssetReference(
+            name: name,
+            location: Location(file: file, line: 1, column: 1),
+            source: .interfaceBuilder
+        )
+    }
 }

Sources/PeripheryKit/ScanResultBuilder.swift

@@ -8,6 +8,7 @@ public enum ScanResultBuilder {
         let removableDeclarations = graph.unusedDeclarations
             .subtracting(assignOnlyProperties)
             .union(graph.unusedModuleImports)
+            .union(graph.unusedImageAssets)
         let redundantProtocols = graph.redundantProtocols.filter { !removableDeclarations.contains($0.0) }
         let redundantPublicAccessibility = graph.redundantPublicAccessibility.filter { !removableDeclarations.contains($0.0) }
 

Sources/ProjectDrivers/GenericProjectDriver.swift

@@ -9,6 +9,7 @@ import SystemPackage
 public final class GenericProjectDriver {
     struct GenericConfig: Decodable {
         let indexstores: Set<String>
+        let assetCatalogs: Set<String>?
         let plists: Set<String>
         let xibs: Set<String>
         let xcdatamodels: Set<String>
@@ -17,6 +18,7 @@ public final class GenericProjectDriver {
     }
 
     private let indexstorePaths: Set<FilePath>
+    private let assetCatalogPaths: Set<FilePath>
     private let plistPaths: Set<FilePath>
     private let xibPaths: Set<FilePath>
     private let xcDataModelsPaths: Set<FilePath>
@@ -33,6 +35,7 @@ public final class GenericProjectDriver {
         decoder.keyDecodingStrategy = .convertFromSnakeCase
         let data = try Data(contentsOf: genericProjectConfig.url)
         let config = try decoder.decode(GenericConfig.self, from: data)
+        let assetCatalogPaths = (config.assetCatalogs ?? []).mapSet { FilePath.makeAbsolute($0) }
         let plistPaths = config.plists.mapSet { FilePath.makeAbsolute($0) }
         let xibPaths = config.xibs.mapSet { FilePath.makeAbsolute($0) }
         let xcDataModelPaths = config.xcdatamodels.mapSet { FilePath.makeAbsolute($0) }
@@ -41,6 +44,7 @@ public final class GenericProjectDriver {
 
         self.init(
             indexstorePaths: indexstorePaths,
+            assetCatalogPaths: assetCatalogPaths,
             plistPaths: plistPaths,
             xibPaths: xibPaths,
             xcDataModelsPaths: xcDataModelPaths,
@@ -52,6 +56,7 @@ public final class GenericProjectDriver {
 
     private init(
         indexstorePaths: Set<FilePath>,
+        assetCatalogPaths: Set<FilePath>,
         plistPaths: Set<FilePath>,
         xibPaths: Set<FilePath>,
         xcDataModelsPaths: Set<FilePath>,
@@ -60,6 +65,7 @@ public final class GenericProjectDriver {
         configuration: Configuration
     ) {
         self.indexstorePaths = indexstorePaths
+        self.assetCatalogPaths = assetCatalogPaths
         self.plistPaths = plistPaths
         self.xibPaths = xibPaths
         self.xcDataModelsPaths = xcDataModelsPaths
@@ -82,6 +88,7 @@ extension GenericProjectDriver: ProjectDriver {
 
         return IndexPlan(
             sourceFiles: sourceFiles,
+            assetCatalogPaths: assetCatalogPaths,
             plistPaths: plistPaths,
             xibPaths: xibPaths,
             xcDataModelPaths: xcDataModelsPaths,

Sources/ProjectDrivers/SPMProjectDriver.swift

@@ -61,10 +61,12 @@ extension SPMProjectDriver: ProjectDriver {
             configuration: configuration
         )
         let sourceFiles = try collector.collect()
+        let assetCatalogPaths = assetCatalogs(from: description)
         let xibPaths = interfaceBuilderFiles(from: description)
 
         return IndexPlan(
             sourceFiles: sourceFiles,
+            assetCatalogPaths: assetCatalogPaths,
             xibPaths: xibPaths
         )
     }
@@ -100,4 +102,47 @@ extension SPMProjectDriver: ProjectDriver {
 
         return xibFiles
     }
+
+    private func assetCatalogs(from description: PackageDescription) -> Set<FilePath> {
+        var catalogs: Set<FilePath> = []
+
+        for target in description.targets {
+            let targetPath = pkg.path.appending(target.path)
+
+            guard let resources = target.resources else { continue }
+
+            for resource in resources {
+                let resourceFilePath = FilePath(resource.path)
+                let resourcePath: FilePath = resourceFilePath.isAbsolute
+                    ? resourceFilePath
+                    : targetPath.appending(resource.path)
+
+                guard resourcePath.exists else { continue }
+
+                if resourcePath.extension?.lowercased() == "xcassets" {
+                    catalogs.insert(resourcePath)
+                } else {
+                    catalogs.formUnion(assetCatalogs(in: resourcePath))
+                }
+            }
+        }
+
+        return catalogs
+    }
+
+    private func assetCatalogs(in path: FilePath) -> Set<FilePath> {
+        guard let enumerator = FileManager.default.enumerator(
+            at: path.url,
+            includingPropertiesForKeys: [.isDirectoryKey],
+            options: [.skipsHiddenFiles]
+        ) else { return [] }
+
+        var paths: Set<FilePath> = []
+
+        for case let url as URL in enumerator where url.pathExtension == "xcassets" {
+            paths.insert(FilePath(url.path))
+        }
+
+        return paths
+    }
 }