Fixes incorrect formatting when attributes contain line comments by preserving linebreaks

Author: TTOzzi

Sources/SwiftFormat/PrettyPrint/TokenStreamCreator.swift

@@ -3073,12 +3073,19 @@ fileprivate final class TokenStreamCreator: SyntaxVisitor {
               }
             }
           } else {
-            after(element.lastToken(viewMode: .sourceAccurate), tokens: .break(.same, newlines: behavior))
+            let lastToken = element.lastToken(viewMode: .sourceAccurate)
+            if lastToken?.trailingTrivia.hasLineComment == true {
+              after(element.lastToken(viewMode: .sourceAccurate), tokens: .break(.same, newlines: .hard))
+            } else {
+              after(element.lastToken(viewMode: .sourceAccurate), tokens: .break(.same, newlines: behavior))
+            }
           }
         }
       }
       var afterAttributeTokens = [Token.close]
-      if !suppressFinalBreak {
+      if attributes.lastToken(viewMode: .sourceAccurate)?.trailingTrivia.hasLineComment == true {
+        afterAttributeTokens.append(.break(.same, newlines: .hard))
+      } else if !suppressFinalBreak {
         afterAttributeTokens.append(.break(.same, newlines: behavior))
       }
       after(attributes.lastToken(viewMode: .sourceAccurate), tokens: afterAttributeTokens)

Tests/SwiftFormatTests/PrettyPrint/AttributeTests.swift

@@ -623,4 +623,42 @@ final class AttributeTests: PrettyPrintTestCase {
 
     assertPrettyPrintEqual(input: input, expected: expected, linelength: 45)
   }
+
+  func testAttributesWithComment() {
+    let input =
+      """
+      @foo // comment
+      @bar
+      import Baz
+
+      """
+    let expected =
+      """
+      @foo  // comment
+      @bar import Baz
+
+      """
+
+    assertPrettyPrintEqual(input: input, expected: expected, linelength: 45)
+  }
+
+  func testAttributesWithLineAndBlockComments() {
+    let input =
+      """
+      @foo // comment
+      @bar /* comment */
+      @zoo // comment
+      import Baz
+
+      """
+    let expected =
+      """
+      @foo  // comment
+      @bar /* comment */ @zoo  // comment
+      import Baz
+
+      """
+
+    assertPrettyPrintEqual(input: input, expected: expected, linelength: 45)
+  }
 }