Adjustments for merging AttributeSyntax and CustomAttributeSyntax

Author: ahoppen

Sources/SwiftFormatPrettyPrint/TokenStreamCreator.swift

@@ -1584,29 +1584,24 @@ fileprivate final class TokenStreamCreator: SyntaxVisitor {
 
   override func visit(_ node: AttributeSyntax) -> SyntaxVisitorContinueKind {
     before(node.firstToken, tokens: .open)
-    if node.argument != nil {
+    switch node.argument {
+    case .argumentList(let argumentList)?:
+      if let leftParen = node.leftParen, let rightParen = node.rightParen {
+        arrangeFunctionCallArgumentList(
+          argumentList,
+          leftDelimiter: leftParen,
+          rightDelimiter: rightParen,
+          forcesBreakBeforeRightDelimiter: false)
+      }
+    case .some:
       // Wrap the attribute's arguments in their own group, so arguments stay together with a higher
       // affinity than the overall attribute (e.g. allows a break after the opening "(" and then
       // having the entire argument list on 1 line). Necessary spaces and breaks are added inside of
       // the argument, using type specific visitor methods.
       after(node.leftParen, tokens: .break(.open, size: 0), .open(argumentListConsistency()))
       before(node.rightParen, tokens: .break(.close, size: 0), .close)
-    }
-    after(node.lastToken, tokens: .close)
-    return .visitChildren
-  }
-
-  override func visit(_ node: CustomAttributeSyntax) -> SyntaxVisitorContinueKind {
-    // "Custom attributes" are better known to users as "property wrappers".
-    before(node.firstToken, tokens: .open)
-    if let argumentList = node.argumentList,
-      let leftParen = node.leftParen, let rightParen = node.rightParen
-    {
-      arrangeFunctionCallArgumentList(
-        argumentList,
-        leftDelimiter: leftParen,
-        rightDelimiter: rightParen,
-        forcesBreakBeforeRightDelimiter: false)
+    case nil:
+      break
     }
     after(node.lastToken, tokens: .close)
     return .visitChildren

Sources/SwiftFormatRules/NeverUseImplicitlyUnwrappedOptionals.swift

@@ -42,7 +42,7 @@ public final class NeverUseImplicitlyUnwrappedOptionals: SyntaxLintRule {
     // Ignores IBOutlet variables
     if let attributes = node.attributes {
       for attribute in attributes {
-        if (attribute.as(AttributeSyntax.self))?.attributeName.text == "IBOutlet" {
+        if (attribute.as(AttributeSyntax.self))?.attributeName.as(SimpleTypeIdentifierSyntax.self)?.name.text == "IBOutlet" {
           return .skipChildren
         }
       }

Tests/SwiftFormatPrettyPrintTests/AttributeTests.swift

@@ -316,9 +316,6 @@ final class AttributeTests: PrettyPrintTestCase {
   }
 
   func testPropertyWrappers() {
-    // Property wrappers are `CustomAttributeSyntax` nodes (not `AttributeSyntax`) and their
-    // arguments are `TupleExprElementListSyntax` (like regular function call argument lists), so
-    // make sure that those are formatted properly.
     let input =
       """
       struct X {