Fix to arrange attributeList for attributes starting with ifConfig

Author: TTOzzi

Sources/SwiftFormat/PrettyPrint/TokenStreamCreator.swift

@@ -2957,19 +2957,23 @@ fileprivate final class TokenStreamCreator: SyntaxVisitor {
     if let attributes = attributes {
       let behavior: NewlineBehavior = separateByLineBreaks ? .hard : .elective
       before(attributes.firstToken(viewMode: .sourceAccurate), tokens: .open)
-      for element in attributes.dropLast() {
-        if let ifConfig = element.as(IfConfigDeclSyntax.self) {
+      if let ifConfig = attributes.first?.as(IfConfigDeclSyntax.self) {
+        for clause in ifConfig.clauses {
+          if let nestedAttributes = AttributeListSyntax(clause.elements) {
+            arrangeAttributeList(nestedAttributes, suppressFinalBreak: true, separateByLineBreaks: separateByLineBreaks)
+          }
+        }
+      } else {
+        for element in attributes.dropLast() {
+          if let ifConfig = element.as(IfConfigDeclSyntax.self) {
             for clause in ifConfig.clauses {
-                if let nestedAttributes = AttributeListSyntax(clause.elements) {
-                    arrangeAttributeList(
-                        nestedAttributes,
-                        suppressFinalBreak: true,
-                        separateByLineBreaks: separateByLineBreaks
-                    )
-                }
+              if let nestedAttributes = AttributeListSyntax(clause.elements) {
+                arrangeAttributeList(nestedAttributes, suppressFinalBreak: true, separateByLineBreaks: separateByLineBreaks)
+              }
             }
-        } else {
+          } else {
             after(element.lastToken(viewMode: .sourceAccurate), tokens: .break(.same, newlines: behavior))
+          }
         }
       }
       var afterAttributeTokens = [Token.close]

Tests/SwiftFormatTests/PrettyPrint/AttributeTests.swift

@@ -576,4 +576,27 @@ final class AttributeTests: PrettyPrintTestCase {
       configuration.lineBreakBetweenDeclarationAttributes = true
       assertPrettyPrintEqual(input: input, expected: expected, linelength: 80, configuration: configuration)
   }
+
+  func testAttributesStartWithPoundIf() {
+    let input =
+      """
+      #if os(macOS)
+      @available(macOS, unavailable)
+      @_spi(Foo)
+      #endif
+      public let myVar = "Test"
+      
+      """
+    let expected =
+      """
+      #if os(macOS)
+        @available(macOS, unavailable)
+        @_spi(Foo)
+      #endif
+      public let myVar = "Test"
+      
+      """
+    
+    assertPrettyPrintEqual(input: input, expected: expected, linelength: 45)
+  }
 }