BridgeJS: Swift struct support

Author: krodak

Benchmarks/Sources/Generated/JavaScript/BridgeJS.ExportSwift.json

@@ -726,5 +726,8 @@
   "moduleName" : "Benchmarks",
   "protocols" : [
 
+  ],
+  "structs" : [
+
   ]
 }

Examples/PlayBridgeJS/Sources/PlayBridgeJS/Generated/JavaScript/BridgeJS.ExportSwift.json

@@ -142,5 +142,8 @@
   "moduleName" : "PlayBridgeJS",
   "protocols" : [
 
+  ],
+  "structs" : [
+
   ]
 }

Plugins/BridgeJS/Sources/BridgeJSCore/ExportSwift.swift

@@ -476,6 +476,13 @@ extension BridgeType {
             case .exportSwift:
                 return LoweringParameterInfo(loweredParameters: [("caseId", .i32)])
             }
+        case .swiftStruct:
+            switch context {
+            case .importTS:
+                throw BridgeJSCoreError("Swift structs are not yet supported in TypeScript imports")
+            case .exportSwift:
+                return LoweringParameterInfo(loweredParameters: [])
+            }
         case .namespaceEnum:
             throw BridgeJSCoreError("Namespace enums cannot be used as parameters")
         case .optional(let wrappedType):
@@ -552,6 +559,13 @@ extension BridgeType {
             case .exportSwift:
                 return LiftingReturnInfo(valueToLift: .i32)
             }
+        case .swiftStruct:
+            switch context {
+            case .importTS:
+                throw BridgeJSCoreError("Swift structs are not yet supported in TypeScript imports")
+            case .exportSwift:
+                return LiftingReturnInfo(valueToLift: nil)
+            }
         case .namespaceEnum:
             throw BridgeJSCoreError("Namespace enums cannot be used as return values")
         case .optional(let wrappedType):

Plugins/BridgeJS/Sources/BridgeJSCore/ImportTS.swift

@@ -25,7 +25,7 @@ public struct ABINameGenerator {
         let contextPart: String?
         if let staticContext = staticContext {
             switch staticContext {
-            case .className(let name), .enumName(let name):
+            case .className(let name), .enumName(let name), .structName(let name):
                 contextPart = name
             case .namespaceEnum:
                 contextPart = namespacePart
@@ -115,6 +115,7 @@ public enum BridgeType: Codable, Equatable, Hashable, Sendable {
     case associatedValueEnum(String)
     case namespaceEnum(String)
     case swiftProtocol(String)
+    case swiftStruct(String)
     indirect case closure(ClosureSignature)
 }
 
@@ -205,10 +206,51 @@ public struct Effects: Codable, Equatable, Sendable {
 
 public enum StaticContext: Codable, Equatable, Sendable {
     case className(String)
+    case structName(String)
     case enumName(String)
     case namespaceEnum
 }
 
+// MARK: - Struct Skeleton
+
+public struct StructField: Codable, Equatable, Sendable {
+    public let name: String
+    public let type: BridgeType
+
+    public init(name: String, type: BridgeType) {
+        self.name = name
+        self.type = type
+    }
+}
+
+public struct ExportedStruct: Codable, Equatable, Sendable {
+    public let name: 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 init(
+        name: String,
+        swiftCallName: String,
+        explicitAccessControl: String?,
+        properties: [ExportedProperty] = [],
+        constructor: ExportedConstructor? = nil,
+        methods: [ExportedFunction] = [],
+        namespace: [String]?
+    ) {
+        self.name = name
+        self.swiftCallName = swiftCallName
+        self.explicitAccessControl = explicitAccessControl
+        self.properties = properties
+        self.constructor = constructor
+        self.methods = methods
+        self.namespace = namespace
+    }
+}
+
 // MARK: - Enum Skeleton
 
 public struct AssociatedValue: Codable, Equatable, Sendable {
@@ -416,7 +458,7 @@ public struct ExportedClass: Codable {
     }
 }
 
-public struct ExportedConstructor: Codable {
+public struct ExportedConstructor: Codable, Equatable, Sendable {
     public var abiName: String
     public var parameters: [Parameter]
     public var effects: Effects
@@ -457,7 +499,7 @@ public struct ExportedProperty: Codable, Equatable, Sendable {
     public func callName(prefix: String? = nil) -> String {
         if let staticContext = staticContext {
             switch staticContext {
-            case .className(let baseName), .enumName(let baseName):
+            case .className(let baseName), .enumName(let baseName), .structName(let baseName):
                 return "\(baseName).\(name)"
             case .namespaceEnum:
                 if let namespace = namespace, !namespace.isEmpty {
@@ -498,6 +540,7 @@ public struct ExportedSkeleton: Codable {
     public let functions: [ExportedFunction]
     public let classes: [ExportedClass]
     public let enums: [ExportedEnum]
+    public let structs: [ExportedStruct]
     public let protocols: [ExportedProtocol]
     /// Whether to expose exported APIs to the global namespace.
     ///
@@ -511,13 +554,15 @@ public struct ExportedSkeleton: Codable {
         functions: [ExportedFunction],
         classes: [ExportedClass],
         enums: [ExportedEnum],
+        structs: [ExportedStruct] = [],
         protocols: [ExportedProtocol] = [],
         exposeToGlobal: Bool
     ) {
         self.moduleName = moduleName
         self.functions = functions
         self.classes = classes
         self.enums = enums
+        self.structs = structs
         self.protocols = protocols
         self.exposeToGlobal = exposeToGlobal
     }
@@ -624,6 +669,9 @@ extension BridgeType {
         case .swiftProtocol:
             // Protocols pass JSObject IDs as Int32
             return .i32
+        case .swiftStruct:
+            // Structs use stack-based return (no direct WASM return type)
+            return nil
         case .closure:
             // Closures pass callback ID as Int32
             return .i32
@@ -660,6 +708,8 @@ extension BridgeType {
             return "\(name.count)\(name)O"
         case .swiftProtocol(let name):
             return "\(name.count)\(name)P"
+        case .swiftStruct(let name):
+            return "\(name.count)\(name)V"
         case .closure(let signature):
             let params =
                 signature.parameters.isEmpty

Plugins/BridgeJS/Sources/BridgeJSLink/BridgeJSLink.swift

@@ -0,0 +1,44 @@
+@JS struct DataPoint {
+    let x: Double
+    let y: Double
+    var label: String
+    var optCount: Int?
+    var optFlag: Bool?
+
+    @JS init(x: Double, y: Double, label: String, optCount: Int?, optFlag: Bool?)
+}
+
+@JS struct Address {
+    var street: String
+    var city: String
+    var zipCode: Int?
+}
+
+@JS struct Person {
+    var name: String
+    var age: Int
+    var address: Address
+    var email: String?
+}
+
+@JS class Greeter {
+    @JS var name: String
+
+    @JS init(name: String)
+    @JS func greet() -> String
+}
+
+@JS struct Session {
+    var id: Int
+    var owner: Greeter
+}
+
+@JS func roundtrip(_ session: Person) -> Person
+
+@JS struct ConfigStruct {
+    @JS static let maxRetries: Int = 3
+    @JS nonisolated(unsafe) static var defaultConfig: String = "production"
+    @JS nonisolated(unsafe) static var timeout: Double = 30.0
+    @JS static var computedSetting: String { "Config: \(defaultConfig)" }
+    @JS static func update(_ timeout: Double) -> Double
+}

Plugins/BridgeJS/Sources/BridgeJSLink/JSGlueGen.swift

@@ -26,6 +26,8 @@ export async function createInstantiator(options, swift) {
     let tmpParamInts = [];
     let tmpParamF32s = [];
     let tmpParamF64s = [];
+    let tmpRetPointers = [];
+    let tmpParamPointers = [];
 
     let _exports = null;
     let bjs = null;
@@ -91,6 +93,12 @@ export async function createInstantiator(options, swift) {
             bjs["swift_js_pop_param_f64"] = function() {
                 return tmpParamF64s.pop();
             }
+            bjs["swift_js_push_pointer"] = function(pointer) {
+                tmpRetPointers.push(pointer);
+            }
+            bjs["swift_js_pop_param_pointer"] = function() {
+                return tmpParamPointers.pop();
+            }
             bjs["swift_js_return_optional_bool"] = function(isSome, value) {
                 if (isSome === 0) {
                     tmpRetOptionalBool = null;

Plugins/BridgeJS/Sources/BridgeJSSkeleton/BridgeJSSkeleton.swift

@@ -26,6 +26,8 @@ export async function createInstantiator(options, swift) {
     let tmpParamInts = [];
     let tmpParamF32s = [];
     let tmpParamF64s = [];
+    let tmpRetPointers = [];
+    let tmpParamPointers = [];
 
     let _exports = null;
     let bjs = null;
@@ -91,6 +93,12 @@ export async function createInstantiator(options, swift) {
             bjs["swift_js_pop_param_f64"] = function() {
                 return tmpParamF64s.pop();
             }
+            bjs["swift_js_push_pointer"] = function(pointer) {
+                tmpRetPointers.push(pointer);
+            }
+            bjs["swift_js_pop_param_pointer"] = function() {
+                return tmpParamPointers.pop();
+            }
             bjs["swift_js_return_optional_bool"] = function(isSome, value) {
                 if (isSome === 0) {
                     tmpRetOptionalBool = null;