only use JS-module paths in skeletons, defer file handling to link time

Author: sliemeobn

Plugins/BridgeJS/Package.swift

@@ -57,7 +57,6 @@ let package = Package(
             dependencies: [
                 "BridgeJSCore",
                 "BridgeJSLink",
-                "BridgeJSBuildPlugin",
                 "TS2Swift",
                 .product(name: "SwiftParser", package: "swift-syntax"),
                 .product(name: "SwiftSyntax", package: "swift-syntax"),

Plugins/BridgeJS/Sources/BridgeJSBuildPlugin/BridgeJSBuildPlugin.swift

@@ -27,8 +27,7 @@ struct BridgeJSBuildPlugin: BuildToolPlugin {
         .map(\.url)
 
         let configFile = pathToConfigFile(target: target)
-        let inputJavaScriptFiles = discoverJavaScriptModuleFiles(in: target.directoryURL)
-        var inputFiles: [URL] = inputSwiftFiles + inputJavaScriptFiles
+        var inputFiles: [URL] = inputSwiftFiles
         if FileManager.default.fileExists(atPath: configFile.path) {
             inputFiles.append(configFile)
         }
@@ -78,7 +77,7 @@ struct BridgeJSBuildPlugin: BuildToolPlugin {
         }
 
         let allSwiftFiles = inputSwiftFiles + pluginGeneratedSwiftFiles
-        arguments.append(contentsOf: (allSwiftFiles + inputJavaScriptFiles).map(\.path))
+        arguments.append(contentsOf: allSwiftFiles.map(\.path))
 
         return .buildCommand(
             displayName: "Generate BridgeJS code",

Plugins/BridgeJS/Sources/BridgeJSCommandPlugin/BridgeJSCommandPlugin.swift

@@ -184,7 +184,6 @@ extension BridgeJSCommandPlugin.Context {
                 !$0.url.path.hasPrefix(generatedDirectory.path + "/")
             }.map(\.url.path)
         )
-        generateArguments.append(contentsOf: discoverJavaScriptModuleFiles(in: target.directoryURL).map(\.path))
         generateArguments.append(contentsOf: remainingArguments)
 
         try runBridgeJSTool(arguments: generateArguments)

Plugins/BridgeJS/Sources/BridgeJSCommandPlugin/BridgeJSPluginUtilities

@@ -23,8 +23,8 @@ public final class SwiftToSkeleton {
 
     private var sourceFiles: [(sourceFile: SourceFileSyntax, inputFilePath: String)] = []
     private var usedExternalModules = Set<String>()
-    private let javaScriptModuleSource: (String) throws -> String?
-    private var importedJSModules: [String: ImportedJSModule] = [:]
+    private let javaScriptModuleExists: (String) throws -> Bool
+    private var validatedJavaScriptModulePaths = Set<String>()
 
     /// Non-fatal diagnostics collected during `finalize()`. These do not fail the build.
     public private(set) var warnings: [(file: String, diagnostic: DiagnosticError)] = []
@@ -35,13 +35,13 @@ public final class SwiftToSkeleton {
         exposeToGlobal: Bool,
         externalModuleIndex: ExternalModuleIndex,
         identityMode: String? = nil,
-        javaScriptModuleSource: @escaping (String) throws -> String? = { _ in nil }
+        javaScriptModuleExists: @escaping (String) throws -> Bool = { _ in false }
     ) {
         self.progress = progress
         self.moduleName = moduleName
         self.exposeToGlobal = exposeToGlobal
         self.identityMode = identityMode
-        self.javaScriptModuleSource = javaScriptModuleSource
+        self.javaScriptModuleExists = javaScriptModuleExists
         self.typeDeclResolver = TypeDeclResolver()
         self.externalModuleIndex = externalModuleIndex
 
@@ -100,7 +100,7 @@ public final class SwiftToSkeleton {
                 + importCollector.importedGlobalGetters.compactMap(\.from)
             let modulePaths = Set(importOrigins.compactMap(\.modulePath))
             for path in modulePaths.sorted() {
-                if importedJSModules[path] != nil {
+                if validatedJavaScriptModulePaths.contains(path) {
                     continue
                 }
                 let pathNode = importCollector.importedModulePathNodes[path] ?? Syntax(sourceFile)
@@ -114,7 +114,26 @@ public final class SwiftToSkeleton {
                     )
                     continue
                 }
-                guard let source = try javaScriptModuleSource(path) else {
+                guard !path.split(separator: "/").contains("..") else {
+                    importCollector.errors.append(
+                        DiagnosticError(
+                            node: pathNode,
+                            message: "JavaScript module paths must not contain '..': '\(path)'."
+                        )
+                    )
+                    continue
+                }
+                let lowercasedPath = path.lowercased()
+                guard lowercasedPath.hasSuffix(".js") || lowercasedPath.hasSuffix(".mjs") else {
+                    importCollector.errors.append(
+                        DiagnosticError(
+                            node: pathNode,
+                            message: "JavaScript modules must use a '.js' or '.mjs' extension: '\(path)'."
+                        )
+                    )
+                    continue
+                }
+                guard try javaScriptModuleExists(path) else {
                     importCollector.errors.append(
                         DiagnosticError(
                             node: pathNode,
@@ -123,7 +142,7 @@ public final class SwiftToSkeleton {
                     )
                     continue
                 }
-                importedJSModules[path] = ImportedJSModule(path: path, source: source)
+                validatedJavaScriptModulePaths.insert(path)
             }
 
             let exportErrors = exportCollector.errors.filter { $0.severity == .error }
@@ -164,11 +183,7 @@ public final class SwiftToSkeleton {
             throw BridgeJSCoreDiagnosticError(diagnostics: diagnostics)
         }
         let importedSkeleton: ImportedModuleSkeleton? = {
-            let modules = importedJSModules.values.sorted { $0.path < $1.path }
-            let module = ImportedModuleSkeleton(
-                children: importedFiles,
-                modules: modules.isEmpty ? nil : modules
-            )
+            let module = ImportedModuleSkeleton(children: importedFiles)
             if module.children.allSatisfy({ $0.functions.isEmpty && $0.types.isEmpty && $0.globalGetters.isEmpty }) {
                 return nil
             }

Plugins/BridgeJS/Sources/BridgeJSCore/SwiftToSkeleton.swift

@@ -41,10 +41,12 @@ public struct BridgeJSLink {
         return configIdentityMode == "pointer"
     }
 
-    mutating func addSkeletonFile(data: Data) throws {
+    @discardableResult
+    mutating func addSkeletonFile(data: Data) throws -> BridgeJSSkeleton {
         do {
             let unified = try JSONDecoder().decode(BridgeJSSkeleton.self, from: data)
             skeletons.append(unified)
+            return unified
         } catch {
             struct SkeletonDecodingError: Error, CustomStringConvertible {
                 let description: String
@@ -1226,9 +1228,9 @@ public struct BridgeJSLink {
         return printer.lines.joined(separator: "\n")
     }
 
-    public func link() throws -> BridgeJSLinkOutput {
+    public func link() throws -> (outputJs: String, outputDts: String) {
         intrinsicRegistry.reset()
-        try importedModuleRegistry.configure(skeletons: skeletons)
+        importedModuleRegistry.configure(skeletons: skeletons)
         intrinsicRegistry.classNamespaces = skeletons.reduce(into: [:]) { result, unified in
             guard let skeleton = unified.exported else { return }
             for klass in skeleton.classes {
@@ -1240,11 +1242,7 @@ public struct BridgeJSLink {
         let data = try collectLinkData()
         let outputJs = try generateJavaScript(data: data)
         let outputDts = generateTypeScript(data: data)
-        return BridgeJSLinkOutput(
-            outputJs: outputJs,
-            outputDts: outputDts,
-            modules: importedModuleRegistry.artifacts
-        )
+        return (outputJs, outputDts)
     }
 
     private func enumHelperAssignments() -> CodeFragmentPrinter {

Plugins/BridgeJS/Sources/BridgeJSLink/BridgeJSLink.swift

@@ -3,42 +3,41 @@ import BridgeJSSkeleton
 #endif
 
 final class ImportedJSModuleRegistry {
-    private struct Key: Hashable {
+    struct Reference: Hashable {
         let swiftModuleName: String
         let path: String
+
+        var relativeOutputPath: String {
+            "bridge-js-modules/\(swiftModuleName)\(path)"
+        }
     }
 
-    private var aliases: [Key: String] = [:]
-    private(set) var artifacts: [BridgeJSLinkOutput.Module] = []
+    private var aliases: [Reference: String] = [:]
+    private(set) var references: [Reference] = []
 
-    func configure(skeletons: [BridgeJSSkeleton]) throws {
+    func configure(skeletons: [BridgeJSSkeleton]) {
         aliases.removeAll(keepingCapacity: true)
-        artifacts.removeAll(keepingCapacity: true)
+        references = Self.collectReferences(skeletons: skeletons)
+        for (index, reference) in references.enumerated() {
+            aliases[reference] = "__bjs_imported_module_\(index)"
+        }
+    }
 
-        var sources: [Key: String] = [:]
+    static func collectReferences(skeletons: [BridgeJSSkeleton]) -> [Reference] {
+        var references = Set<Reference>()
         for skeleton in skeletons {
-            for module in skeleton.imported?.modules ?? [] {
-                guard module.path.hasPrefix("/") else {
-                    throw BridgeJSLinkError(
-                        message: "JavaScript module path must start with '/': \(module.path)"
-                    )
-                }
-                let key = Key(swiftModuleName: skeleton.moduleName, path: module.path)
-                if let existing = sources[key], existing != module.source {
-                    throw BridgeJSLinkError(
-                        message: "Conflicting JavaScript module contents for \(skeleton.moduleName)/\(module.path)"
-                    )
+            for file in skeleton.imported?.children ?? [] {
+                let origins =
+                    file.functions.compactMap(\.from)
+                    + file.globalGetters.compactMap(\.from)
+                    + file.types.compactMap(\.from)
+                for case .module(let path) in origins {
+                    references.insert(Reference(swiftModuleName: skeleton.moduleName, path: path))
                 }
-                sources[key] = module.source
             }
         }
-
-        for (index, entry) in sources.sorted(by: {
-            ($0.key.swiftModuleName, $0.key.path) < ($1.key.swiftModuleName, $1.key.path)
-        }).enumerated() {
-            let relativePath = "bridge-js-modules/\(entry.key.swiftModuleName)\(entry.key.path)"
-            aliases[entry.key] = "__bjs_imported_module_\(index)"
-            artifacts.append(.init(relativePath: relativePath, source: entry.value))
+        return references.sorted {
+            ($0.swiftModuleName, $0.path) < ($1.swiftModuleName, $1.path)
         }
     }
 
@@ -49,19 +48,19 @@ final class ImportedJSModuleRegistry {
         case .global:
             return "globalThis"
         case .module(let path):
-            let key = Key(swiftModuleName: swiftModuleName, path: path)
-            guard let alias = aliases[key] else {
+            let reference = Reference(swiftModuleName: swiftModuleName, path: path)
+            guard let alias = aliases[reference] else {
                 throw BridgeJSLinkError(
-                    message: "Missing embedded JavaScript module for \(swiftModuleName)/\(path)"
+                    message: "Missing JavaScript module \(swiftModuleName)\(path)"
                 )
             }
             return alias
         }
     }
 
     var importLines: [String] {
-        artifacts.enumerated().map { index, artifact in
-            let path = BridgeJSLink.escapeForJavaScriptStringLiteral(artifact.relativePath)
+        references.enumerated().map { index, reference in
+            let path = BridgeJSLink.escapeForJavaScriptStringLiteral(reference.relativeOutputPath)
             return "import * as __bjs_imported_module_\(index) from \"./\(path)\";"
         }
     }

Plugins/BridgeJS/Sources/BridgeJSLink/BridgeJSLinkOutput.swift

@@ -1126,13 +1126,24 @@ private struct AsyncClosureReturnTypeCollector: BridgeSkeletonVisitor {
 /// Controls where BridgeJS reads imported JS values from.
 ///
 /// - `global`: Read from `globalThis`.
+/// - `module`: Read from a target-local ECMAScript module.
 public enum JSImportFrom: Codable, Equatable, Sendable {
     case global
     case module(String)
 
     public init(from decoder: any Decoder) throws {
-        let value = try decoder.singleValueContainer().decode(String.self)
-        self = value == "global" ? .global : .module(value)
+        let container = try decoder.singleValueContainer()
+        let value = try container.decode(String.self)
+        if value == "global" {
+            self = .global
+        } else if value.hasPrefix("/") && !value.split(separator: "/").contains("..") {
+            self = .module(value)
+        } else {
+            throw DecodingError.dataCorruptedError(
+                in: container,
+                debugDescription: "Unknown import origin '\(value)'. Expected \"global\" or a rooted module path."
+            )
+        }
     }
 
     public func encode(to encoder: any Encoder) throws {
@@ -1146,17 +1157,6 @@ public enum JSImportFrom: Codable, Equatable, Sendable {
     }
 }
 
-/// A target-local ECMAScript module embedded into a BridgeJS skeleton.
-public struct ImportedJSModule: Codable, Equatable, Sendable {
-    public let path: String
-    public let source: String
-
-    public init(path: String, source: String) {
-        self.path = path
-        self.source = source
-    }
-}
-
 public struct ImportedFunctionSkeleton: Codable {
     public let name: String
     /// The JavaScript function/method name to call, if different from `name`.
@@ -1482,32 +1482,9 @@ public struct ImportedFileSkeleton: Codable {
 
 public struct ImportedModuleSkeleton: Codable {
     public var children: [ImportedFileSkeleton]
-    public var modules: [ImportedJSModule]?
 
-    public init(children: [ImportedFileSkeleton], modules: [ImportedJSModule]? = nil) {
+    public init(children: [ImportedFileSkeleton]) {
         self.children = children
-        self.modules = modules
-    }
-
-    /// Deterministic non-cryptographic content fingerprint used to invalidate
-    /// build-plugin outputs when only an embedded JavaScript module changes.
-    public var moduleContentFingerprint: String? {
-        guard let modules, !modules.isEmpty else { return nil }
-        var hash: UInt64 = 0xcbf29ce484222325
-        func combine<S: Sequence>(_ bytes: S) where S.Element == UInt8 {
-            for byte in bytes {
-                hash ^= UInt64(byte)
-                hash &*= 0x100000001b3
-            }
-        }
-        for module in modules.sorted(by: { $0.path < $1.path }) {
-            combine(module.path.utf8)
-            combine(CollectionOfOne(UInt8(0)))
-            combine(module.source.utf8)
-            combine(CollectionOfOne(UInt8(0xff)))
-        }
-        let hexadecimal = String(hash, radix: 16)
-        return String(repeating: "0", count: 16 - hexadecimal.count) + hexadecimal
     }
 }