Rewrite vertical_whitespace rule using SwiftSyntax

Source/SwiftLintBuiltInRules/Rules/Style/VerticalWhitespaceRule.swift

@@ -1,9 +1,11 @@
 import Foundation
 import SourceKittenFramework
+import SwiftIDEUtils
+import SwiftSyntax
 
 private let defaultDescriptionReason = "Limit vertical whitespace to a single empty line"
 
-struct VerticalWhitespaceRule: CorrectableRule {
+struct VerticalWhitespaceRule: CorrectableRule, SourceKitFreeRule {
  var configuration = VerticalWhitespaceConfiguration()
 
  static let description = RuleDescription(
@@ -15,12 +17,46 @@ struct VerticalWhitespaceRule: CorrectableRule {
  Example("let abc = 0\n"),
  Example("let abc = 0\n\n"),
  Example("/* bcs \n\n\n\n*/"),
- Example("// bca \n\n")
+ Example("// bca \n\n"),
+ Example(#"""
+ """
+ This is a
+
+
+
+
+ very long
+
+
+
+ string with newlines
+
+
+
+
+
+
+ """
+ """#),
+ Example(#"""
+ example(value: """
+ Something
+
+
+ """)
+ """#)
  ],
  triggeringExamples: [
  Example("let aaaa = 0\n\n\n"),
  Example("struct AAAA {}\n\n\n\n"),
- Example("class BBBB {}\n\n\n")
+ Example("class BBBB {}\n\n\n"),
+ Example("""
+ func foo() {}
+
+
+ // MARK: - Something
+
+ """)
  ],
  corrections: [
  Example("let b = 0\n\n\nclass AAA {}\n"): Example("let b = 0\n\nclass AAA {}\n"),
@@ -67,14 +103,13 @@ struct VerticalWhitespaceRule: CorrectableRule {
  let blankLinesSections = extractSections(from: filteredLines)
 
  // filtering out violations in comments and strings
- let stringAndComments = SyntaxKind.commentAndStringKinds
- let syntaxMap = file.syntaxMap
  let result = blankLinesSections.compactMap { eachSection -> (lastLine: Line, linesToRemove: Int)? in
  guard let lastLine = eachSection.last else {
  return nil
  }
- let kindInSection = syntaxMap.kinds(inByteRange: lastLine.byteRange)
- if stringAndComments.isDisjoint(with: kindInSection) {
+
+ guard let classificationsInRange = file.syntaxTree.classification(at: lastLine.byteRange.location.value),
+ classificationsInRange.kind.isStringOrComment else {
  return (lastLine, eachSection.count)
  }
 
@@ -148,3 +183,15 @@ struct VerticalWhitespaceRule: CorrectableRule {
  return []
  }
 }
+
+private extension SyntaxClassification {
+ var isStringOrComment: Bool {
+ switch self {
+ case .docBlockComment, .docLineComment, .blockComment, .lineComment, .stringLiteral:
+ return true
+ case .attribute, .dollarIdentifier, .editorPlaceholder, .floatLiteral, .identifier,
+ .ifConfigDirective, .integerLiteral, .keyword, .none, .operator, .regexLiteral, .type:
+ return false
+ }
+ }
+}