Improvements to macros in MacroSystemTests

Some general improvements to the usage of SwiftSyntax in the macros in MacroSystemTests and removal of trivia handling in these macros because trivia is being added by MacroSystem now.

Author: ahoppen

Tests/SwiftSyntaxMacroExpansionTest/MacroSystemTests.swift

@@ -10,6 +10,14 @@
 //
 //===----------------------------------------------------------------------===//
 
+//==========================================================================//
+// IMPORTANT: The macros defined in this file are intended to test the      //
+// behavior of MacroSystem. Many of them do not serve as good examples of   //
+// how macros should be written. In particular, they often lack error       //
+// handling because it is not needed in the few test cases in which these   //
+// macros are invoked.                                                      //
+//==========================================================================//
+
 import _SwiftSyntaxTestSupport
 import SwiftDiagnostics
 import SwiftParser
@@ -42,17 +50,13 @@ fileprivate struct DeclsFromStringsMacro: DeclarationMacro, MemberMacro {
   private static func decls(from arguments: LabeledExprListSyntax) -> [DeclSyntax] {
     var strings: [String] = []
     for arg in arguments {
-      guard
-        let value = arg.expression.as(StringLiteralExprSyntax.self)?.representedLiteralValue
-      else {
+      guard let value = arg.expression.as(StringLiteralExprSyntax.self)?.representedLiteralValue else {
         continue
       }
       strings.append(value)
     }
 
-    return strings.map {
-      "\(raw: $0)"
-    }
+    return strings.map { "\(raw: $0)" }
   }
 
   static func expansion(
@@ -98,14 +102,7 @@ fileprivate struct WrapAllProperties: MemberAttributeMacro {
       return []
     }
 
-    return [
-      AttributeSyntax(
-        attributeName: IdentifierTypeSyntax(
-          name: .identifier("Wrapper")
-        )
-      )
-      .with(\.leadingTrivia, [.newlines(1), .spaces(2)])
-    ]
+    return ["@Wrapper"]
   }
 }
 
@@ -123,7 +120,7 @@ final class MacroSystemTests: XCTestCase {
         var argList = macro.argumentList
         argList[argList.startIndex].label = .identifier("_colorLiteralRed")
         let initSyntax: ExprSyntax = ".init(\(argList))"
-        return initSyntax.with(\.leadingTrivia, macro.leadingTrivia)
+        return initSyntax
       }
     }
 
@@ -209,11 +206,10 @@ final class MacroSystemTests: XCTestCase {
         of macro: some FreestandingMacroExpansionSyntax,
         in context: some MacroExpansionContext
       ) throws -> ExprSyntax {
-        guard let sourceLoc: AbstractSourceLocation = context.location(of: macro)
-        else {
+        guard let sourceLoc: AbstractSourceLocation = context.location(of: macro) else {
           throw MacroExpansionErrorMessage("can't find location for macro")
         }
-        return sourceLoc.column.with(\.leadingTrivia, macro.leadingTrivia)
+        return sourceLoc.column
       }
     }
 
@@ -222,11 +218,10 @@ final class MacroSystemTests: XCTestCase {
         of macro: some FreestandingMacroExpansionSyntax,
         in context: some MacroExpansionContext
       ) throws -> ExprSyntax {
-        guard let sourceLoc: AbstractSourceLocation = context.location(of: macro)
-        else {
+        guard let sourceLoc: AbstractSourceLocation = context.location(of: macro) else {
           throw MacroExpansionErrorMessage("can't find location for macro")
         }
-        return sourceLoc.file.with(\.leadingTrivia, macro.leadingTrivia)
+        return sourceLoc.file
       }
     }
 
@@ -348,9 +343,7 @@ final class MacroSystemTests: XCTestCase {
         of node: some FreestandingMacroExpansionSyntax,
         in context: some MacroExpansionContext
       ) throws -> [DeclSyntax] {
-        guard let firstElement = node.argumentList.first,
-          let stringLiteral = firstElement.expression
-            .as(StringLiteralExprSyntax.self),
+        guard let stringLiteral = node.argumentList.first?.expression.as(StringLiteralExprSyntax.self),
           stringLiteral.segments.count == 1,
           case let .stringSegment(prefix) = stringLiteral.segments.first
         else {
@@ -394,8 +387,7 @@ final class MacroSystemTests: XCTestCase {
         providingAccessorsOf declaration: some DeclSyntaxProtocol,
         in context: some MacroExpansionContext
       ) throws -> [AccessorDeclSyntax] {
-        guard let varDecl = declaration.as(VariableDeclSyntax.self),
-          let binding = varDecl.bindings.first,
+        guard let binding = declaration.as(VariableDeclSyntax.self)?.bindings.first,
           let identifier = binding.pattern.as(IdentifierPatternSyntax.self)?.identifier,
           binding.accessorBlock == nil
         else {
@@ -421,8 +413,7 @@ final class MacroSystemTests: XCTestCase {
         providingPeersOf declaration: some DeclSyntaxProtocol,
         in context: some MacroExpansionContext
       ) throws -> [SwiftSyntax.DeclSyntax] {
-        guard let varDecl = declaration.as(VariableDeclSyntax.self),
-          let binding = varDecl.bindings.first,
+        guard let binding = declaration.as(VariableDeclSyntax.self)?.bindings.first,
           let identifier = binding.pattern.as(IdentifierPatternSyntax.self)?.identifier,
           let type = binding.typeAnnotation?.type,
           binding.accessorBlock == nil
@@ -431,8 +422,7 @@ final class MacroSystemTests: XCTestCase {
         }
 
         guard case .argumentList(let arguments) = node.arguments,
-          let wrapperTypeNameExpr = arguments.first?.expression,
-          let stringLiteral = wrapperTypeNameExpr.as(StringLiteralExprSyntax.self),
+          let stringLiteral = arguments.first?.expression.as(StringLiteralExprSyntax.self),
           stringLiteral.segments.count == 1,
           case let .stringSegment(wrapperTypeNameSegment)? = stringLiteral.segments.first
         else {
@@ -715,33 +705,23 @@ final class MacroSystemTests: XCTestCase {
         }
 
         // Form the completion handler parameter.
-        let resultType: TypeSyntax? = funcDecl.signature.returnClause?.type.with(\.leadingTrivia, []).with(\.trailingTrivia, [])
+        let resultType: TypeSyntax? = funcDecl.signature.returnClause?.type.trimmed
 
         let completionHandlerParam =
           FunctionParameterSyntax(
             firstName: .identifier("completionHandler"),
             colon: .colonToken(trailingTrivia: .space),
-            type: "(\(resultType ?? "")) -> Void" as TypeSyntax
+            type: TypeSyntax("(\(resultType ?? "")) -> Void")
           )
 
         // Add the completion handler parameter to the parameter list.
         let parameterList = funcDecl.signature.parameterClause.parameters
-        let newParameterList: FunctionParameterListSyntax
-        if let lastParam = parameterList.last {
+        var newParameterList = parameterList
+        if !parameterList.isEmpty {
           // We need to add a trailing comma to the preceding list.
-          let newParameterListElements =
-            parameterList.dropLast()
-            + [
-              lastParam.with(
-                \.trailingComma,
-                .commaToken(trailingTrivia: .space)
-              ),
-              completionHandlerParam,
-            ]
-          newParameterList = FunctionParameterListSyntax(newParameterListElements)
-        } else {
-          newParameterList = parameterList + [completionHandlerParam]
+          newParameterList[newParameterList.index(before: newParameterList.endIndex)].trailingComma = .commaToken(trailingTrivia: .space)
         }
+        newParameterList.append(completionHandlerParam)
 
         let callArguments: [String] = parameterList.map { param in
           let argName = param.secondName ?? param.firstName
@@ -775,34 +755,13 @@ final class MacroSystemTests: XCTestCase {
           return attribute.attributeName.as(IdentifierTypeSyntax.self)?.name == "addCompletionHandler"
         }
 
-        let newFunc =
-          funcDecl
-          .with(
-            \.signature,
-            funcDecl.signature
-              .with(
-                \.effectSpecifiers,
-                funcDecl.signature.effectSpecifiers?.with(\.asyncSpecifier, nil)  // drop async
-              )
-              .with(\.returnClause, nil)  // drop result type
-              .with(
-                \.parameterClause,  // add completion handler parameter
-                funcDecl.signature.parameterClause.with(\.parameters, newParameterList)
-                  .with(\.trailingTrivia, [])
-              )
-          )
-          .with(
-            \.body,
-            CodeBlockSyntax(
-              leftBrace: .leftBraceToken(leadingTrivia: .space),
-              statements: CodeBlockItemListSyntax(
-                [CodeBlockItemSyntax(item: .expr(newBody))]
-              ),
-              rightBrace: .rightBraceToken(leadingTrivia: .newline)
-            )
-          )
-          .with(\.attributes, newAttributeList)
-          .with(\.leadingTrivia, .newlines(2))
+        var newFunc = funcDecl
+        newFunc.signature.effectSpecifiers?.asyncSpecifier = nil  // drop async
+        newFunc.signature.returnClause = nil  // drop result type
+        newFunc.signature.parameterClause.parameters = newParameterList
+        newFunc.signature.parameterClause.trailingTrivia = []
+        newFunc.body = CodeBlockSyntax { newBody }
+        newFunc.attributes = newAttributeList
 
         return [DeclSyntax(newFunc)]
       }
@@ -833,13 +792,8 @@ final class MacroSystemTests: XCTestCase {
         of node: AttributeSyntax,
         providingMembersOf decl: some DeclGroupSyntax,
         in context: some MacroExpansionContext
-      )
-        throws -> [DeclSyntax]
-      {
-        let storage: DeclSyntax = "var _storage: Storage<Self>"
-        return [
-          storage.with(\.leadingTrivia, [.newlines(1), .spaces(2)])
-        ]
+      ) throws -> [DeclSyntax] {
+        return ["var _storage: Storage<Self>"]
       }
     }
 
@@ -963,14 +917,7 @@ final class MacroSystemTests: XCTestCase {
           return []
         }
 
-        return [
-          AttributeSyntax(
-            attributeName: IdentifierTypeSyntax(
-              name: .identifier("Wrapper")
-            )
-          )
-          .with(\.leadingTrivia, [.newlines(1), .spaces(2)])
-        ]
+        return ["@Wrapper"]
       }
     }
 
@@ -1021,13 +968,7 @@ final class MacroSystemTests: XCTestCase {
         providingAttributesFor member: some DeclSyntaxProtocol,
         in context: some MacroExpansionContext
       ) throws -> [AttributeSyntax] {
-        return [
-          AttributeSyntax(
-            attributeName: IdentifierTypeSyntax(
-              name: .identifier("Wrapper")
-            )
-          )
-        ]
+        return ["@Wrapper"]
       }
     }
 
@@ -1116,15 +1057,7 @@ final class MacroSystemTests: XCTestCase {
         providingAttributesFor member: some DeclSyntaxProtocol,
         in context: some MacroExpansionContext
       ) throws -> [AttributeSyntax] {
-        return [
-          AttributeSyntax(
-            leadingTrivia: .blockComment("/* start */"),
-            attributeName: IdentifierTypeSyntax(
-              name: .identifier("Wrapper")
-            ),
-            trailingTrivia: .blockComment("/* end */")
-          )
-        ]
+        return ["/* start */@Wrapper/* end */"]
       }
     }
 
@@ -1207,13 +1140,10 @@ final class MacroSystemTests: XCTestCase {
 
   func testTypeWrapperTransform() {
     struct CustomTypeWrapperMacro: MemberMacro, MemberAttributeMacro, AccessorMacro {
-      static func expansion<
-        Declaration: DeclGroupSyntax,
-        Context: MacroExpansionContext
-      >(
+      static func expansion(
         of node: AttributeSyntax,
-        providingMembersOf declaration: Declaration,
-        in context: Context
+        providingMembersOf declaration: some DeclGroupSyntax,
+        in context: some MacroExpansionContext
       ) throws -> [DeclSyntax] {
         return ["var _storage: Wrapper<Self>"]
       }
@@ -1224,14 +1154,7 @@ final class MacroSystemTests: XCTestCase {
         providingAttributesFor member: some DeclSyntaxProtocol,
         in context: some MacroExpansionContext
       ) throws -> [AttributeSyntax] {
-        return [
-          AttributeSyntax(
-            attributeName: IdentifierTypeSyntax(
-              name: .identifier("customTypeWrapper")
-            )
-          )
-          .with(\.leadingTrivia, [.newlines(1), .spaces(2)])
-        ]
+        return ["@customTypeWrapper"]
       }
 
       static func expansion(
@@ -1342,15 +1265,8 @@ final class MacroSystemTests: XCTestCase {
           )
         }
 
-        return identifiers.map { identifier in
-          CodeBlockItemSyntax(
-            item: CodeBlockItemSyntax.Item.stmt(
-              """
-
-              guard let \(raw: identifier.text) else \(elseBlock(identifier))
-              """
-            )
-          )
+        return identifiers.map { (identifier) -> CodeBlockItemSyntax in
+          "guard let \(raw: identifier.text) else \(elseBlock(identifier))"
         }
       }
     }
@@ -1410,17 +1326,13 @@ final class MacroSystemTests: XCTestCase {
       ) throws -> [DeclSyntax] {
         var strings: [String] = []
         for arg in node.argumentList {
-          guard
-            let value = arg.expression.as(StringLiteralExprSyntax.self)?.representedLiteralValue
-          else {
+          guard let value = arg.expression.as(StringLiteralExprSyntax.self)?.representedLiteralValue else {
             continue
           }
           strings.append(value)
         }
 
-        return strings.map {
-          "\(raw: $0)"
-        }
+        return strings.map { "\(raw: $0)" }
       }
     }