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BridgeJS: Allow extensions to contain types #803

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9c8cb0b
BridgeJS: Allow extensions to contain types
wfltaylor Aug 14, 2026
779553d
BridgeJS: Fix nested type references in generated TS
wfltaylor Aug 14, 2026
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97 changes: 57 additions & 40 deletions Plugins/BridgeJS/Sources/BridgeJSCore/SwiftToSkeleton.swift
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Original file line number Diff line number Diff line change
Expand Up @@ -525,12 +525,12 @@ public final class SwiftToSkeleton {

if let typeDecl = typeDeclResolver.resolve(type) {
if typeDecl.is(ProtocolDeclSyntax.self) {
let swiftCallName = SwiftToSkeleton.computeSwiftCallName(for: typeDecl, itemName: typeDecl.name.text)
let swiftCallName = computeSwiftCallName(for: typeDecl, itemName: typeDecl.name.text)
return .swiftProtocol(swiftCallName)
}

if let enumDecl = typeDecl.as(EnumDeclSyntax.self) {
let swiftCallName = SwiftToSkeleton.computeSwiftCallName(for: enumDecl, itemName: enumDecl.name.text)
let swiftCallName = computeSwiftCallName(for: enumDecl, itemName: enumDecl.name.text)
if let jsAttribute = enumDecl.attributes.firstJSAttribute,
let aliasTarget = extractAliasTarget(from: jsAttribute)
{
Expand Down Expand Up @@ -569,7 +569,7 @@ public final class SwiftToSkeleton {
}

if let structDecl = typeDecl.as(StructDeclSyntax.self) {
let swiftCallName = SwiftToSkeleton.computeSwiftCallName(
let swiftCallName = computeSwiftCallName(
for: structDecl,
itemName: structDecl.name.text
)
Expand All @@ -587,7 +587,7 @@ public final class SwiftToSkeleton {
guard typeDecl.is(ClassDeclSyntax.self) || typeDecl.is(ActorDeclSyntax.self) else {
return nil
}
let swiftCallName = SwiftToSkeleton.computeSwiftCallName(for: typeDecl, itemName: typeDecl.name.text)
let swiftCallName = computeSwiftCallName(for: typeDecl, itemName: typeDecl.name.text)

// A type annotated with @JSClass is a JavaScript object wrapper (imported),
// even if it is declared as a Swift class.
Expand Down Expand Up @@ -627,7 +627,7 @@ public final class SwiftToSkeleton {
private func resolveExternal(for type: TypeSyntax, errors: inout [DiagnosticError]) -> BridgeType? {
guard
!externalModuleIndex.isEmpty,
var components = typeDeclResolver.qualifiedComponents(from: type)
var components = type.qualifiedComponents
else {
return nil
}
Expand Down Expand Up @@ -766,27 +766,50 @@ public final class SwiftToSkeleton {
return nil
}

/// Computes the full Swift call name by walking up the AST hierarchy to find all parent enums
/// This currently doesn’t work correctly for extensions on types defined in other modules,
/// which is fine for now since we don’t support extending @JS types from other modules.
/// This will need updating when we do.
fileprivate func enclosingDeclarations(of node: some SyntaxProtocol) -> [Syntax] {
var declarations: [Syntax] = []
var visitedExtendedTypes: Set<SyntaxIdentifier> = []
var currentNode: Syntax? = Syntax(node).parent

while let parent = currentNode {
if let extensionDecl = parent.as(ExtensionDeclSyntax.self) {
if let extendedDecl = typeDeclResolver.resolve(extensionDecl.extendedType),
visitedExtendedTypes.insert(extendedDecl.id).inserted
{
declarations.append(Syntax(extendedDecl))
currentNode = Syntax(extendedDecl).parent
} else {
currentNode = parent.parent
}
} else {
declarations.append(parent)
currentNode = parent.parent
}
}
return declarations
}

/// This generates the qualified name needed for Swift code generation (e.g., "Networking.API.HTTPServer")
fileprivate static func computeSwiftCallName(for node: some SyntaxProtocol, itemName: String) -> String {
fileprivate func computeSwiftCallName(for node: some SyntaxProtocol, itemName: String) -> String {
var swiftPath: [String] = []
var currentNode: Syntax? = node.parent

while let parent = currentNode {
if let enumDecl = parent.as(EnumDeclSyntax.self),
for declaration in enclosingDeclarations(of: node) {
if let enumDecl = declaration.as(EnumDeclSyntax.self),
enumDecl.attributes.hasJSAttribute()
{
swiftPath.insert(enumDecl.name.text, at: 0)
} else if let structDecl = parent.as(StructDeclSyntax.self),
} else if let structDecl = declaration.as(StructDeclSyntax.self),
structDecl.attributes.hasJSAttribute()
{
swiftPath.insert(structDecl.name.text, at: 0)
} else if let classDecl = parent.as(ClassDeclSyntax.self),
} else if let classDecl = declaration.as(ClassDeclSyntax.self),
classDecl.attributes.hasJSAttribute()
{
swiftPath.insert(classDecl.name.text, at: 0)
}
currentNode = parent.parent
}

if swiftPath.isEmpty {
Expand Down Expand Up @@ -1861,7 +1884,7 @@ private final class ExportSwiftAPICollector: SyntaxAnyVisitor {
resolvedNamespace: namespaceResult.namespace,
parentTypeNamespace: computeParentTypeNamespace(for: node)
)
let swiftCallName = SwiftToSkeleton.computeSwiftCallName(for: node, itemName: name)
let swiftCallName = parent.computeSwiftCallName(for: node, itemName: name)
let explicitAccessControl = computeExplicitAtLeastInternalAccessControl(
for: node,
message: "Class visibility must be at least internal"
Expand Down Expand Up @@ -1921,25 +1944,23 @@ private final class ExportSwiftAPICollector: SyntaxAnyVisitor {
}

/// Walks extension members under the matching type’s state, returning whether the type was found.
///
/// Note: The lookup scans dictionaries keyed by `makeKey(name:namespace:)`, matching only by
/// plain name. If two types share a name but differ by namespace, `.first(where:)` picks
/// whichever comes first. This is acceptable today since namespace collisions are unlikely,
/// but may need refinement if namespace-qualified extension resolution is added.
func resolveExtension(_ ext: ExtensionDeclSyntax) -> Bool {
let name = ext.extendedType.trimmedDescription
guard let extendedDecl = parent.typeDeclResolver.resolve(ext.extendedType) else {
return false

@krodak krodak Aug 15, 2026

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Deferred extension resolution works well for cross-file declarations, but a single pass leaves it dependent on source order.

I put extension Library.Shelf before the extension Library that declares Shelf. The generated struct was present, but the earlier extension's method was missing. Reversing the declarations restored it.

Could we retry unresolved extensions until a pass makes no progress? A reversed-order cross-file test would cover the same case across input files.

var pending = exportCollectors.flatMap { collector in
    collector.deferredExtensions.map { (owner: collector, extension: $0) }
}

repeat {
    let previousCount = pending.count
    pending.removeAll { item in
        exportCollectors.contains { $0.resolveExtension(item.extension) }
    }
    if pending.count == previousCount {
        break
    }
} while !pending.isEmpty

for item in pending {
    item.owner.diagnoseUnresolvedExtension(item.extension)
}

}
let swiftCallName = parent.computeSwiftCallName(for: extendedDecl, itemName: extendedDecl.name.text)
let state: State
if let entry = exportedClassByName.first(where: { $0.value.name == name }) {
state = .classBody(name: name, key: entry.key)
} else if let entry = exportedStructByName.first(where: { $0.value.name == name }) {
state = .structBody(name: name, key: entry.key)
} else if let entry = exportedEnumByName.first(where: { $0.value.name == name }) {
state = .enumBody(name: name, key: entry.key)
} else if exportedProtocolByName.values.contains(where: { $0.name == name }) {
if let entry = exportedClassByName.first(where: { $0.value.swiftCallName == swiftCallName }) {
state = .classBody(name: entry.value.name, key: entry.key)
} else if let entry = exportedStructByName.first(where: { $0.value.swiftCallName == swiftCallName }) {
state = .structBody(name: entry.value.name, key: entry.key)
} else if let entry = exportedEnumByName.first(where: { $0.value.swiftCallName == swiftCallName }) {
state = .enumBody(name: entry.value.name, key: entry.key)
} else if exportedProtocolByName.values.contains(where: { $0.name == swiftCallName }) {
diagnose(
node: ext.extendedType,
message: "Protocol extensions are not supported by BridgeJS.",
hint: "You cannot extend `@JS` protocol '\(name)' with additional members"
hint: "You cannot extend `@JS` protocol '\(swiftCallName)' with additional members"
)
return true
} else {
Expand All @@ -1958,7 +1979,7 @@ private final class ExportSwiftAPICollector: SyntaxAnyVisitor {
jsAttribute: AttributeSyntax,
aliasTarget: TypeSyntax
) {
let swiftCallName = SwiftToSkeleton.computeSwiftCallName(for: node, itemName: node.name.text)
let swiftCallName = parent.computeSwiftCallName(for: node, itemName: node.name.text)
if extractNamespace(from: jsAttribute) != nil {
errors.append(
DiagnosticError(
Expand Down Expand Up @@ -2023,7 +2044,7 @@ private final class ExportSwiftAPICollector: SyntaxAnyVisitor {
parentTypeNamespace: computeParentTypeNamespace(for: node)
)
let emitStyle = extractEnumStyle(from: jsAttribute) ?? .const
let swiftCallName = SwiftToSkeleton.computeSwiftCallName(for: node, itemName: name)
let swiftCallName = parent.computeSwiftCallName(for: node, itemName: name)
let explicitAccessControl = computeExplicitAtLeastInternalAccessControl(
for: node,
message: "Enum visibility must be at least internal"
Expand Down Expand Up @@ -2209,7 +2230,7 @@ private final class ExportSwiftAPICollector: SyntaxAnyVisitor {
resolvedNamespace: namespaceResult.namespace,
parentTypeNamespace: computeParentTypeNamespace(for: node)
)
let swiftCallName = SwiftToSkeleton.computeSwiftCallName(for: node, itemName: name)
let swiftCallName = parent.computeSwiftCallName(for: node, itemName: name)
let explicitAccessControl = computeExplicitAtLeastInternalAccessControl(
for: node,
message: "Struct visibility must be at least internal"
Expand Down Expand Up @@ -2524,10 +2545,9 @@ private final class ExportSwiftAPICollector: SyntaxAnyVisitor {
/// Method allows for explicit namespace for top level enum, it will be used as base namespace and will concat enum name
private func computeNamespace(for node: some SyntaxProtocol) -> [String]? {
var namespace: [String] = []
var currentNode: Syntax? = node.parent

while let parent = currentNode {
if let enumDecl = parent.as(EnumDeclSyntax.self),
for declaration in parent.enclosingDeclarations(of: node) {
if let enumDecl = declaration.as(EnumDeclSyntax.self),
enumDecl.attributes.hasJSAttribute()
{
let isNamespaceEnum = !enumDecl.memberBlock.members.contains { member in
Expand All @@ -2544,27 +2564,24 @@ private final class ExportSwiftAPICollector: SyntaxAnyVisitor {
}
}
}
currentNode = parent.parent
}

return namespace.isEmpty ? nil : namespace
}

private func computeParentTypeNamespace(for node: some SyntaxProtocol) -> [String]? {
var path: [String] = []
var currentNode: Syntax? = node.parent

while let parent = currentNode {
if let structDecl = parent.as(StructDeclSyntax.self),
for declaration in parent.enclosingDeclarations(of: node) {
if let structDecl = declaration.as(StructDeclSyntax.self),
structDecl.attributes.hasJSAttribute()
{
path.insert(structDecl.name.text, at: 0)
} else if let classDecl = parent.as(ClassDeclSyntax.self),
} else if let classDecl = declaration.as(ClassDeclSyntax.self),
classDecl.attributes.hasJSAttribute()
{
path.insert(classDecl.name.text, at: 0)
}
currentNode = parent.parent
}

return path.isEmpty ? nil : path
Expand Down
54 changes: 37 additions & 17 deletions Plugins/BridgeJS/Sources/BridgeJSCore/TypeDeclResolver.swift
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Original file line number Diff line number Diff line change
Expand Up @@ -16,8 +16,7 @@ class TypeDeclResolver {

private class TypeDeclCollector: SyntaxVisitor {
let resolver: TypeDeclResolver
var scope: [TypeDecl] = []
var rootTypeDecls: [TypeDecl] = []
var scope: [String] = []

init(resolver: TypeDeclResolver) {
self.resolver = resolver
Expand All @@ -26,17 +25,14 @@ class TypeDeclResolver {

func visitNominalDecl(_ node: TypeDecl) -> SyntaxVisitorContinueKind {
let name = node.name.text
let qualifiedName = scope.map(\.name.text) + [name]
let qualifiedName = scope + [name]
resolver.typeDeclByQualifiedName[qualifiedName] = node
scope.append(node)
scope.append(name)
return .visitChildren
}

func visitPostNominalDecl() {
let type = scope.removeLast()
if scope.isEmpty {
rootTypeDecls.append(type)
}
scope.removeLast()
}

override func visit(_ node: StructDeclSyntax) -> SyntaxVisitorContinueKind {
Expand Down Expand Up @@ -72,10 +68,21 @@ class TypeDeclResolver {

override func visit(_ node: TypeAliasDeclSyntax) -> SyntaxVisitorContinueKind {
let name = node.name.text
let qualifiedName = scope.map(\.name.text) + [name]
let qualifiedName = scope + [name]
resolver.typeAliasByQualifiedName[qualifiedName] = node
return .skipChildren
}

override func visit(_ node: ExtensionDeclSyntax) -> SyntaxVisitorContinueKind {
guard let components = node.memberScopeComponents else {
return .skipChildren
}
scope.append(contentsOf: components)
return .visitChildren
}
override func visitPost(_ node: ExtensionDeclSyntax) {
scope.removeLast(node.memberScopeComponents?.count ?? 0)
}
}

/// Collects type declarations from a parsed Swift source file
Expand All @@ -91,6 +98,10 @@ class TypeDeclResolver {
while let parent = context.parent {
if let parent = parent.asProtocol(NamedDeclSyntax.self), parent.isProtocol(DeclGroupSyntax.self) {
innerToOuter.append(parent.name.text)
} else if let extensionDecl = parent.as(ExtensionDeclSyntax.self),
let components = extensionDecl.memberScopeComponents
{
innerToOuter.append(contentsOf: components.reversed())
}
context = parent
}
Expand All @@ -106,7 +117,7 @@ class TypeDeclResolver {
/// Search for the type declaration from the innermost scope to the outermost scope
for i in (0...scope.count).reversed() {
let qualifiedName = Array(scope[0..<i] + [name])
if typeDeclByQualifiedName[qualifiedName] != nil {
if typeDeclByQualifiedName[qualifiedName] != nil || typeAliasByQualifiedName[qualifiedName] != nil {
return qualifiedName
}
}
Expand All @@ -132,15 +143,15 @@ class TypeDeclResolver {
///
/// Resolution strategy:
/// 1. If the node is IdentifierTypeSyntax, call `lookupType(for:)` which attempts scope-aware qualification via `tryQualify`.
/// 2. Otherwise, attempt to build a fully qualified name with `qualifiedComponents(from:)` and look it up with `lookupType(fullyQualified:)`.
/// 2. Otherwise, attempt to build a fully qualified name with `qualifiedComponents` and look it up with `lookupType(fullyQualified:)`.
///
/// - Parameter type: The SwiftSyntax node representing a type appearance in source code.
/// - Returns: The nominal declaration (enum/class/actor/struct) if found, otherwise nil.
func resolve(_ type: TypeSyntax) -> TypeDecl? {
if let id = type.as(IdentifierTypeSyntax.self) {
return lookupType(for: id)
}
if let components = qualifiedComponents(from: type) {
if let components = type.qualifiedComponents {
return lookupType(fullyQualified: components)

@krodak krodak Aug 15, 2026

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FYI, extension scoping now handles unqualified names, but relative qualified names such as Shelf.Divider are still treated as root-qualified. An @JS method using that spelling is omitted from the skeleton instead of resolving it as Library.Shelf.Divider.

This behavior already exists before this PR, so I opened #805 to follow it separately rather than treating it as part of this change.

}
return nil
Expand All @@ -155,20 +166,29 @@ class TypeDeclResolver {
let qualifiedName = tryQualify(type: id)
return typeAliasByQualifiedName[qualifiedName]
}
if let components = qualifiedComponents(from: type) {
if let components = type.qualifiedComponents {
return typeAliasByQualifiedName[components]
}
return nil
}

func qualifiedComponents(from type: TypeSyntax) -> QualifiedName? {
if let m = type.as(MemberTypeSyntax.self) {
guard let base = qualifiedComponents(from: TypeSyntax(m.baseType)) else { return nil }
}

extension TypeSyntax {
var qualifiedComponents: TypeDeclResolver.QualifiedName? {
if let m = self.as(MemberTypeSyntax.self) {
guard let base = TypeSyntax(m.baseType).qualifiedComponents else { return nil }
return base + [m.name.text]
} else if let id = type.as(IdentifierTypeSyntax.self) {
} else if let id = self.as(IdentifierTypeSyntax.self) {
return [id.name.text]
} else {
return nil
}
}
}

extension ExtensionDeclSyntax {
var memberScopeComponents: TypeDeclResolver.QualifiedName? {
extendedType.qualifiedComponents
}
}
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