Fix unexpected expansion (#7)

* Update MacroTesting example tests

This brings in the latest versions of Apple's macro demos and tests from
SwiftSyntax.

* Fix unexpected expansion

Fixes #6.

* wip

* wip

Author: stephencelis

Package.resolved

@@ -18,7 +18,7 @@ let package = Package(
   ],
   dependencies: [
     .package(url: "https://github.com/apple/swift-syntax.git", from: "509.0.0"),
-    .package(url: "https://github.com/pointfreeco/swift-snapshot-testing", from: "1.14.0"),
+    .package(url: "https://github.com/pointfreeco/swift-snapshot-testing", from: "1.14.1"),
   ],
   targets: [
     .target(

Package.swift

@@ -297,9 +297,7 @@ public func assertMacro(
       )
     }
 
-    if allDiagnostics.filter({ $0.diagMessage.severity == .error }).isEmpty
-      || expandedSource != nil
-    {
+    if allDiagnostics.filter({ $0.diagMessage.severity == .error }).isEmpty {
       offset += 1
       assertInlineSnapshot(
         of: expandedSourceFile.description.trimmingCharacters(in: .newlines),

Sources/MacroTesting/AssertMacro.swift

@@ -42,30 +42,23 @@ public struct AddAsyncMacro: PeerMacro {
     }
 
     // This only makes sense void functions
-    if funcDecl.signature.returnClause?.type.with(\.leadingTrivia, []).with(\.trailingTrivia, [])
-      .description != "Void"
-    {
+    if funcDecl.signature.returnClause?.type.with(\.leadingTrivia, []).with(\.trailingTrivia, []).description != "Void" {
       throw CustomError.message(
         "@addAsync requires an function that returns void"
       )
     }
 
     // Requires a completion handler block as last parameter
-    guard
-      let completionHandlerParameterAttribute = funcDecl.signature.parameterClause.parameters.last?
-        .type.as(AttributedTypeSyntax.self),
-      let completionHandlerParameter = completionHandlerParameterAttribute.baseType.as(
-        FunctionTypeSyntax.self)
+    guard let completionHandlerParameterAttribute = funcDecl.signature.parameterClause.parameters.last?.type.as(AttributedTypeSyntax.self),
+      let completionHandlerParameter = completionHandlerParameterAttribute.baseType.as(FunctionTypeSyntax.self)
     else {
       throw CustomError.message(
         "@addAsync requires an function that has a completion handler as last parameter"
       )
     }
 
     // Completion handler needs to return Void
-    if completionHandlerParameter.returnClause.type.with(\.leadingTrivia, []).with(
-      \.trailingTrivia, []
-    ).description != "Void" {
+    if completionHandlerParameter.returnClause.type.with(\.leadingTrivia, []).with(\.trailingTrivia, []).description != "Void" {
       throw CustomError.message(
         "@addAsync requires an function that has a completion handler that returns Void"
       )
@@ -74,18 +67,14 @@ public struct AddAsyncMacro: PeerMacro {
     let returnType = completionHandlerParameter.parameters.first?.type
 
     let isResultReturn = returnType?.children(viewMode: .all).first?.description == "Result"
-    let successReturnType =
-      isResultReturn
-      ? returnType!.as(IdentifierTypeSyntax.self)!.genericArgumentClause?.arguments.first!.argument
-      : returnType
+    let successReturnType = isResultReturn ? returnType!.as(IdentifierTypeSyntax.self)!.genericArgumentClause?.arguments.first!.argument : returnType
 
     // Remove completionHandler and comma from the previous parameter
     var newParameterList = funcDecl.signature.parameterClause.parameters
     newParameterList.removeLast()
     let newParameterListLastParameter = newParameterList.last!
     newParameterList.removeLast()
-    newParameterList.append(
-      newParameterListLastParameter.with(\.trailingTrivia, []).with(\.trailingComma, nil))
+    newParameterList.append(newParameterListLastParameter.with(\.trailingTrivia, []).with(\.trailingComma, nil))
 
     // Drop the @addAsync attribute from the new declaration.
     let newAttributeList = funcDecl.attributes.filter {
@@ -147,9 +136,7 @@ public struct AddAsyncMacro: PeerMacro {
           )
           .with(
             \.returnClause,
-            successReturnType != nil
-              ? ReturnClauseSyntax(
-                leadingTrivia: .space, type: successReturnType!.with(\.leadingTrivia, .space)) : nil
+            successReturnType != nil ? ReturnClauseSyntax(leadingTrivia: .space, type: successReturnType!.with(\.leadingTrivia, .space)) : nil
           )  // add result type
           .with(
             \.parameterClause,

Tests/MacroTestingTests/MacroExamples/AddAsyncMacro.swift

@@ -73,8 +73,7 @@ public struct AddCompletionHandlerMacro: PeerMacro {
     }
 
     // Form the completion handler parameter.
-    let resultType: TypeSyntax? = funcDecl.signature.returnClause?.type.with(\.leadingTrivia, [])
-      .with(\.trailingTrivia, [])
+    let resultType: TypeSyntax? = funcDecl.signature.returnClause?.type.with(\.leadingTrivia, []).with(\.trailingTrivia, [])
 
     let completionHandlerParam =
       FunctionParameterSyntax(

Tests/MacroTestingTests/MacroExamples/AddCompletionHandlerMacro.swift

@@ -24,22 +24,18 @@ public enum CustomCodable: MemberMacro {
     let cases = memberList.compactMap({ member -> String? in
       // is a property
       guard
-        let propertyName = member.decl.as(VariableDeclSyntax.self)?.bindings.first?.pattern.as(
-          IdentifierPatternSyntax.self)?.identifier.text
+        let propertyName = member.decl.as(VariableDeclSyntax.self)?.bindings.first?.pattern.as(IdentifierPatternSyntax.self)?.identifier.text
       else {
         return nil
       }
 
       // if it has a CodableKey macro on it
-      if let customKeyMacro = member.decl.as(VariableDeclSyntax.self)?.attributes.first(where: {
-        element in
-        element.as(AttributeSyntax.self)?.attributeName.as(IdentifierTypeSyntax.self)?.description
-          == "CodableKey"
+      if let customKeyMacro = member.decl.as(VariableDeclSyntax.self)?.attributes.first(where: { element in
+        element.as(AttributeSyntax.self)?.attributeName.as(IdentifierTypeSyntax.self)?.description == "CodableKey"
       }) {
 
         // Uses the value in the Macro
-        let customKeyValue = customKeyMacro.as(AttributeSyntax.self)!.arguments!.as(
-          LabeledExprListSyntax.self)!.first!.expression
+        let customKeyValue = customKeyMacro.as(AttributeSyntax.self)!.arguments!.as(LabeledExprListSyntax.self)!.first!.expression
 
         return "case \(propertyName) = \(customKeyValue)"
       } else {

Tests/MacroTestingTests/MacroExamples/CustomCodable.swift

@@ -21,9 +21,7 @@ public struct MetaEnumMacro {
   let access: DeclModifierListSyntax.Element?
   let parentParamName: TokenSyntax
 
-  init(
-    node: AttributeSyntax, declaration: some DeclGroupSyntax, context: some MacroExpansionContext
-  ) throws {
+  init(node: AttributeSyntax, declaration: some DeclGroupSyntax, context: some MacroExpansionContext) throws {
     guard let enumDecl = declaration.as(EnumDeclSyntax.self) else {
       throw DiagnosticsError(diagnostics: [
         CaseMacroDiagnostic.notAnEnum(declaration).diagnose(at: Syntax(node))
@@ -96,7 +94,7 @@ extension EnumDeclSyntax {
   var caseElements: [EnumCaseElementSyntax] {
     memberBlock.members.flatMap { member in
       guard let caseDecl = member.decl.as(EnumCaseDeclSyntax.self) else {
-        return [EnumCaseElementSyntax]()
+        return Array<EnumCaseElementSyntax>()
       }
 
       return Array(caseDecl.elements)
@@ -112,8 +110,7 @@ extension CaseMacroDiagnostic: DiagnosticMessage {
   var message: String {
     switch self {
     case .notAnEnum(let decl):
-      return
-        "'@MetaEnum' can only be attached to an enum, not \(decl.descriptiveDeclKind(withArticle: true))"
+      return "'@MetaEnum' can only be attached to an enum, not \(decl.descriptiveDeclKind(withArticle: true))"
     }
   }
 

Tests/MacroTestingTests/MacroExamples/MetaEnumMacro.swift

@@ -30,8 +30,7 @@ extension NewTypeMacro: MemberMacro {
           .expression.as(MemberAccessExprSyntax.self),
         let rawType = memberAccessExn.base?.as(DeclReferenceExprSyntax.self)
       else {
-        throw CustomError.message(
-          #"@NewType requires the raw type as an argument, in the form "RawType.self"."#)
+        throw CustomError.message(#"@NewType requires the raw type as an argument, in the form "RawType.self"."#)
       }
 
       guard let declaration = declaration.as(StructDeclSyntax.self) else {

Tests/MacroTestingTests/MacroExamples/NewTypeMacro.swift

@@ -155,8 +155,9 @@ extension OptionSetMacro: ExtensionMacro {
 
     // If there is an explicit conformance to OptionSet already, don't add one.
     if let inheritedTypes = structDecl.inheritanceClause?.inheritedTypes,
-      inheritedTypes.contains(where: { inherited in inherited.type.trimmedDescription == "OptionSet"
-        })
+      inheritedTypes.contains(
+        where: { inherited in inherited.type.trimmedDescription == "OptionSet" }
+      )
     {
       return []
     }

Tests/MacroTestingTests/MacroExamples/OptionSetMacro.swift

@@ -43,8 +43,7 @@ public struct WrapStoredPropertiesMacro: MemberAttributeMacro {
       stringLiteral.segments.count == 1,
       case let .stringSegment(wrapperName)? = stringLiteral.segments.first
     else {
-      throw CustomError.message(
-        "macro requires a string literal containing the name of an attribute")
+      throw CustomError.message("macro requires a string literal containing the name of an attribute")
     }
 
     return [