BridgeJS: Support custom exported type names

Author: krodak

Plugins/BridgeJS/Sources/BridgeJSCore/SwiftToSkeleton.swift

@@ -43,7 +43,7 @@ final class JSGlueVariableScope {
 
     private let intrinsicRegistry: JSIntrinsicRegistry
 
-    private var variables: Set<String> = [
+    static let reservedVariables: Set<String> = [
         reservedSwift,
         reservedInstance,
         reservedMemory,
@@ -77,6 +77,8 @@ final class JSGlueVariableScope {
         reservedRegisterTypeHandles,
     ]
 
+    private var variables = JSGlueVariableScope.reservedVariables
+
     init(intrinsicRegistry: JSIntrinsicRegistry) {
         self.intrinsicRegistry = intrinsicRegistry
     }
@@ -110,6 +112,14 @@ final class JSGlueVariableScope {
         intrinsicRegistry.typeOwnerModules[typeName]
     }
 
+    func exportedClassPath(forSwiftName name: String) -> [String]? {
+        intrinsicRegistry.classPaths[name]
+    }
+
+    func renamedEnumNames(forSwiftName name: String) -> (value: String, type: String)? {
+        intrinsicRegistry.renamedEnumNames[name]
+    }
+
     func makeChildScope() -> JSGlueVariableScope {
         JSGlueVariableScope(intrinsicRegistry: intrinsicRegistry)
     }
@@ -554,12 +564,31 @@ struct IntrinsicJSFragment: Sendable {
         }
 
         func classReference(forQualifiedName qualifiedName: String) -> String {
+            if let path = scope.exportedClassPath(forSwiftName: qualifiedName), let name = path.last {
+                if hasDirectAccessToSwiftClass {
+                    return name
+                }
+                return path.count == 1 ? "_exports['\(name)']" : "_exports.\(path.joined(separator: "."))"
+            }
             if hasDirectAccessToSwiftClass {
                 return unqualifiedClassName(for: qualifiedName)
             }
             let unqualified = unqualifiedClassName(for: qualifiedName)
             return exportsAccess(forClass: unqualified)
         }
+
+        func defaultValueTypeName(_ type: BridgeType, _ format: DefaultValueUtils.OutputFormat) -> String? {
+            switch type {
+            case .swiftHeapObject(let name):
+                guard let jsName = scope.exportedClassPath(forSwiftName: name)?.last else { return nil }
+                return format == .javascript ? classReference(forQualifiedName: name) : jsName
+            case .caseEnum(let name):
+                guard let renamed = scope.renamedEnumNames(forSwiftName: name) else { return nil }
+                return format == .javascript ? renamed.value : renamed.type
+            default:
+                return nil
+            }
+        }
     }
 
     /// A function that prints the fragment code.
@@ -2565,7 +2594,10 @@ struct IntrinsicJSFragment: Sendable {
 
             // Attach instance methods to the struct instance
             for method in structDef.methods where !method.effects.isStatic {
-                let paramList = DefaultValueUtils.formatParameterList(method.parameters)
+                let paramList = DefaultValueUtils.formatParameterList(
+                    method.parameters,
+                    resolveTypeName: context.defaultValueTypeName
+                )
                 printer.write(
                     "\(instanceVar).\(method.resolvedJSName) = function(\(paramList)) {"
                 )

Plugins/BridgeJS/Sources/BridgeJSLink/BridgeJSLink.swift

@@ -6,6 +6,8 @@ import BridgeJSUtilities
 final class JSIntrinsicRegistry {
     private var entries: [String: [String]] = [:]
     var classNamespaces: [String: [String]] = [:]
+    var classPaths: [String: [String]] = [:]
+    var renamedEnumNames: [String: (value: String, type: String)] = [:]
 
     var typeOwnerModules: [String: String] = [:]
 
@@ -43,6 +45,8 @@ final class JSIntrinsicRegistry {
     func reset() {
         entries.removeAll()
         classNamespaces.removeAll()
+        classPaths.removeAll()
+        renamedEnumNames.removeAll()
         typeOwnerModules.removeAll()
         codecNameOrder.removeAll()
         codecBodies.removeAll()

Plugins/BridgeJS/Sources/BridgeJSLink/JSGlueGen.swift

@@ -4,10 +4,17 @@
 
 public protocol NamespacedExportedType {
     var name: String { get }
+    var jsName: String? { get }
+    /// The namespace using Swift declaration names, retained for ABI generation.
     var namespace: [String]? { get }
+    /// The public namespace when an enclosing declaration has an exported name override.
+    var jsNamespace: [String]? { get }
 }
 
 extension NamespacedExportedType {
+    public var resolvedJSName: String { jsName ?? name }
+    public var resolvedJSNamespace: [String]? { jsNamespace ?? namespace }
+
     public var abiName: String {
         if let namespace = namespace, !namespace.isEmpty {
             return (namespace + [name]).joined(separator: "_")
@@ -16,7 +23,7 @@ extension NamespacedExportedType {
     }
 
     public var tsPathComponents: [String] {
-        (namespace ?? []) + [name]
+        (resolvedJSNamespace ?? []) + [resolvedJSName]
     }
 
     public var tsFullPath: String {
@@ -778,31 +785,37 @@ public struct StructField: Codable, Equatable, Sendable {
 
 public struct ExportedStruct: Codable, Equatable, Sendable, NamespacedExportedType {
     public let name: String
+    public let jsName: String?
     public let swiftCallName: String
     public let explicitAccessControl: String?
     public var properties: [ExportedProperty]
     public var constructor: ExportedConstructor?
     public var methods: [ExportedFunction]
     public let namespace: [String]?
+    public let jsNamespace: [String]?
     public var documentation: String?
 
     public init(
         name: String,
+        jsName: String? = nil,
         swiftCallName: String,
         explicitAccessControl: String?,
         properties: [ExportedProperty] = [],
         constructor: ExportedConstructor? = nil,
         methods: [ExportedFunction] = [],
         namespace: [String]?,
+        jsNamespace: [String]? = nil,
         documentation: String? = nil
     ) {
         self.name = name
+        self.jsName = jsName
         self.swiftCallName = swiftCallName
         self.explicitAccessControl = explicitAccessControl
         self.properties = properties
         self.constructor = constructor
         self.methods = methods
         self.namespace = namespace
+        self.jsNamespace = jsNamespace
         self.documentation = documentation
     }
 }
@@ -864,12 +877,14 @@ public struct ExportedEnum: Codable, Equatable, Sendable, NamespacedExportedType
     public static let objectSuffix = "Object"
 
     public let name: String
+    public let jsName: String?
     public let swiftCallName: String
     public let tsFullPath: String
     public let explicitAccessControl: String?
     public var cases: [EnumCase]
     public let rawType: SwiftEnumRawType?
     public let namespace: [String]?
+    public let jsNamespace: [String]?
     public let emitStyle: EnumEmitStyle
     public var staticMethods: [ExportedFunction]
     public var staticProperties: [ExportedProperty] = []
@@ -885,33 +900,39 @@ public struct ExportedEnum: Codable, Equatable, Sendable, NamespacedExportedType
     }
 
     public var valuesName: String {
-        emitStyle == .tsEnum ? name : "\(name)\(Self.valuesSuffix)"
+        emitStyle == .tsEnum ? resolvedJSName : "\(resolvedJSName)\(Self.valuesSuffix)"
     }
 
     public var objectTypeName: String {
-        "\(name)\(Self.objectSuffix)"
+        "\(resolvedJSName)\(Self.objectSuffix)"
     }
 
     public init(
         name: String,
+        jsName: String? = nil,
         swiftCallName: String,
         tsFullPath: String,
         explicitAccessControl: String?,
         cases: [EnumCase],
         rawType: SwiftEnumRawType?,
         namespace: [String]?,
+        jsNamespace: [String]? = nil,
         emitStyle: EnumEmitStyle,
         staticMethods: [ExportedFunction] = [],
         staticProperties: [ExportedProperty] = [],
         documentation: String? = nil
     ) {
         self.name = name
+        self.jsName = jsName
         self.swiftCallName = swiftCallName
-        self.tsFullPath = tsFullPath
+        self.tsFullPath =
+            jsName != nil || jsNamespace != nil
+            ? ((jsNamespace ?? namespace ?? []) + [jsName ?? name]).joined(separator: ".") : tsFullPath
         self.explicitAccessControl = explicitAccessControl
         self.cases = cases
         self.rawType = rawType
         self.namespace = namespace
+        self.jsNamespace = jsNamespace
         self.emitStyle = emitStyle
         self.staticMethods = staticMethods
         self.staticProperties = staticProperties
@@ -947,24 +968,30 @@ public struct ExportedProtocolProperty: Codable, Equatable, Sendable {
     }
 }
 
-public struct ExportedProtocol: Codable, Equatable {
+public struct ExportedProtocol: Codable, Equatable, NamespacedExportedType {
     public let name: String
+    public let jsName: String?
     public let methods: [ExportedFunction]
     public let properties: [ExportedProtocolProperty]
     public let namespace: [String]?
+    public let jsNamespace: [String]?
     public var documentation: String?
 
     public init(
         name: String,
+        jsName: String? = nil,
         methods: [ExportedFunction],
         properties: [ExportedProtocolProperty] = [],
         namespace: [String]? = nil,
+        jsNamespace: [String]? = nil,
         documentation: String? = nil
     ) {
         self.name = name
+        self.jsName = jsName
         self.methods = methods
         self.properties = properties
         self.namespace = namespace
+        self.jsNamespace = jsNamespace
         self.documentation = documentation
     }
 }
@@ -1007,35 +1034,41 @@ public struct ExportedFunction: Codable, Equatable, Sendable {
 
 public struct ExportedClass: Codable, NamespacedExportedType {
     public var name: String
+    public var jsName: String?
     public var swiftCallName: String
     public var explicitAccessControl: String?
     public var constructor: ExportedConstructor?
     public var methods: [ExportedFunction]
     public var properties: [ExportedProperty]
     public var namespace: [String]?
+    public var jsNamespace: [String]?
     public var identityMode: Bool?  // nil = use config default, true/false = override
     public var documentation: String?
     public var isFinal: Bool?
 
     public init(
         name: String,
+        jsName: String? = nil,
         swiftCallName: String,
         explicitAccessControl: String?,
         constructor: ExportedConstructor? = nil,
         methods: [ExportedFunction],
         properties: [ExportedProperty] = [],
         namespace: [String]? = nil,
+        jsNamespace: [String]? = nil,
         identityMode: Bool? = nil,
         documentation: String? = nil,
         isFinal: Bool? = nil
     ) {
         self.name = name
+        self.jsName = jsName
         self.swiftCallName = swiftCallName
         self.explicitAccessControl = explicitAccessControl
         self.constructor = constructor
         self.methods = methods
         self.properties = properties
         self.namespace = namespace
+        self.jsNamespace = jsNamespace
         self.identityMode = identityMode
         self.documentation = documentation
         self.isFinal = isFinal

Plugins/BridgeJS/Sources/BridgeJSLink/JSIntrinsicRegistry.swift

@@ -697,39 +697,50 @@ import Testing
     }
 
     @Test
-    func jsNameOnClassDiagnostic() throws {
+    func jsNameOnClassIsAccepted() {
         let source = """
             @JS("Renamed") class Box { @JS init() {} }
             """
-        let diagnostics = try #require(moduleDiagnostics(source: source))
-        #expect(diagnostics.description.contains("A separate name for JavaScript is not supported here"))
+        #expect(moduleDiagnostics(source: source) == nil)
     }
 
     @Test
-    func jsNameOnStructDiagnostic() throws {
+    func jsNameOnStructIsAccepted() {
         let source = """
             @JS("Renamed") struct Box { var x: Int }
             """
-        let diagnostics = try #require(moduleDiagnostics(source: source))
-        #expect(diagnostics.description.contains("A separate name for JavaScript is not supported here"))
+        #expect(moduleDiagnostics(source: source) == nil)
     }
 
     @Test
-    func jsNameOnEnumDiagnostic() throws {
+    func jsNameOnEnumIsAccepted() {
         let source = """
             @JS("Renamed") enum Box { case a }
             """
-        let diagnostics = try #require(moduleDiagnostics(source: source))
-        #expect(diagnostics.description.contains("A separate name for JavaScript is not supported here"))
+        #expect(moduleDiagnostics(source: source) == nil)
     }
 
     @Test
-    func jsNameOnProtocolDiagnostic() throws {
+    func jsNameOnProtocolIsAccepted() {
         let source = """
             @JS("Renamed") protocol Box { func run() }
             """
-        let diagnostics = try #require(moduleDiagnostics(source: source))
-        #expect(diagnostics.description.contains("A separate name for JavaScript is not supported here"))
+        #expect(moduleDiagnostics(source: source) == nil)
+    }
+
+    @Test(
+        arguments: ["class Box {}", "struct Box {}", "enum Box { case a }", "protocol Box {}"],
+        ["1invalid", "has space", "has-dash", ""]
+    )
+    func invalidTypeJSNameDiagnostic(declaration: String, name: String) throws {
+        let diagnostics = try #require(moduleDiagnostics(source: "@JS(\"\(name)\") \(declaration)"))
+        #expect(diagnostics.description.contains("`\(name)` is not a valid JavaScript identifier"))
+    }
+
+    @Test(arguments: ["class Box {}", "struct Box {}", "enum Box { case a }", "protocol Box {}"])
+    func jsNameOnRepresentationAliasDiagnostic(declaration: String) throws {
+        let diagnostics = try #require(moduleDiagnostics(source: "@JS(\"PublicBox\", as: String.self) \(declaration)"))
+        #expect(diagnostics.description.contains("A separate name for JavaScript is not supported on `@JS(as:)` types"))
     }
 
     @Test
@@ -741,6 +752,15 @@ import Testing
         #expect(diagnostics.description.contains("A separate name for JavaScript is not supported here"))
     }
 
+    @Test(arguments: ["class", "default", "await", "string", "number"])
+    func reservedExportedTypeNamesAreRejected(name: String) throws {
+        let source = """
+            @JS("\(name)") class Box { @JS init() {} }
+            """
+        let diagnostics = try #require(moduleDiagnostics(source: source))
+        #expect(diagnostics.description.contains("cannot be used as an exported type name"))
+    }
+
     @Test
     func jsNameOnProtocolRequirementDiagnostic() throws {
         let source = """