Ignore too long end of line comments when they're wrapped in printControl tokens that disable breaking.

The rationale here is that if the comment exists in a section of code where breaking is purposefully disabled, then there's probably a reason that the comment cannot be moved to another line. The `printControl` tokens that disable breaking are the signal to the pretty print algorithm for which sections are those special "no breaks allowed here", and it can just respect those when diagnosing long lines.

Author: dylansturg

Sources/SwiftFormat/PrettyPrint/PrettyPrint.swift

@@ -515,7 +515,7 @@ public class PrettyPrinter {
 
       write(comment.print(indent: currentIndentation))
       if wasEndOfLine {
-        if comment.length > spaceRemaining {
+        if comment.length > spaceRemaining && !isBreakingSuppressed {
           diagnose(.moveEndOfLineComment, category: .endOfLineComment)
         }
       } else {

Sources/SwiftFormat/PrettyPrint/TokenStreamCreator.swift

@@ -2742,9 +2742,10 @@ fileprivate final class TokenStreamCreator: SyntaxVisitor {
   ///   will stay inside the group.
   ///
   /// * If the trailing comment is a line comment, we first append any enqueued after-tokens
-  ///   that are *not* breaks or newlines, then we append the comment, and then the remaining
-  ///   after-tokens. Due to visitation ordering, this ensures that a trailing line comment is
-  ///   not incorrectly inserted into the token stream *after* a break or newline.
+  ///   that are *not*  related to breaks or newlines (e.g. includes print control tokens), then
+  ///   we append the comment, and then the remaining after-tokens. Due to visitation ordering,
+  ///   this ensures that a trailing line comment is not incorrectly inserted into the token stream
+  ///   *after* a break or newline.
   private func appendAfterTokensAndTrailingComments(_ token: TokenSyntax) {
     let (wasLineComment, trailingCommentTokens) = afterTokensForTrailingComment(token)
     let afterGroups = afterMap.removeValue(forKey: token) ?? []
@@ -2759,7 +2760,7 @@ fileprivate final class TokenStreamCreator: SyntaxVisitor {
         var shouldExtractTrailingComment = false
         if wasLineComment && !hasAppendedTrailingComment {
           switch afterToken {
-          case .break: shouldExtractTrailingComment = true
+          case .break, .printerControl: shouldExtractTrailingComment = true
           default: break
           }
         }

Tests/SwiftFormatTests/PrettyPrint/CommentTests.swift

@@ -1,3 +1,5 @@
+import _SwiftFormatTestSupport
+
 final class CommentTests: PrettyPrintTestCase {
   func testDocumentationComments() {
     let input =
@@ -408,7 +410,7 @@ final class CommentTests: PrettyPrintTestCase {
         case quux
       }
       """
-    
+
     let expected =
       """
       struct Foo {
@@ -424,7 +426,7 @@ final class CommentTests: PrettyPrintTestCase {
       }
 
       """
-    
+
     assertPrettyPrintEqual(input: input, expected: expected, linelength: 100)
   }
 
@@ -594,25 +596,25 @@ final class CommentTests: PrettyPrintTestCase {
 
   func testCommentsInIfStatements() {
     let input =
-    """
-         if foo.bar && false && // comment about foo.bar
-           baz && // comment about baz
-           // comment about next
-           next
-           && // other is important
-           // second line about other
-           other &&
-           // comment about final on a new line
-           final
-         {
-         }
-         if foo.bar && foo.baz
-           && // comment about the next line
-           // another comment line
-           next.line
-         {
-         }
-         """
+      """
+      if foo.bar && false && // comment about foo.bar
+        baz && // comment about baz
+        // comment about next
+        next
+        && // other is important
+        // second line about other
+        other &&
+        // comment about final on a new line
+        final
+      {
+      }
+      if foo.bar && foo.baz
+        && // comment about the next line
+        // another comment line
+        next.line
+      {
+      }
+      """
 
     let expected =
       """
@@ -682,4 +684,32 @@ final class CommentTests: PrettyPrintTestCase {
 
     assertPrettyPrintEqual(input: input, expected: expected, linelength: 60)
   }
+
+  func testDiagnoseMoveEndOfLineComment() {
+    assertPrettyPrintEqual(
+      input: """
+        import veryveryverylongmodulenameherebecauseitistypical  // special sentinel comment
+
+        func fooBarBazRunningOutOfIdeas() {  1️⃣// comment that needs to move
+          if foo {  // comment is fine
+          }
+        }
+
+        """,
+      expected: """
+        import veryveryverylongmodulenameherebecauseitistypical  // special sentinel comment
+
+        func fooBarBazRunningOutOfIdeas() {  // comment that needs to move
+          if foo {  // comment is fine
+          }
+        }
+
+        """,
+      linelength: 45,
+      whitespaceOnly: true,
+      findings: [
+        FindingSpec("1️⃣", message: "move end-of-line comment that exceeds the line length"),
+      ]
+    )
+  }
 }