Support comments when removing spaces between chained functions (#1723)

Sources/Rules.swift

@@ -1188,10 +1188,12 @@ public struct _FormatRules {
  ) { formatter in
  formatter.forEach(.operator(".", .infix)) { i, _ in
  let endOfLine = formatter.endOfLine(at: i)
- if let nextIndex = formatter.index(of: .nonSpaceOrLinebreak, after: endOfLine, if: {
- $0 == .operator(".", .infix)
- }) {
- let startOfLine = formatter.startOfLine(at: nextIndex)
+ if let nextIndex = formatter.index(of: .nonSpaceOrCommentOrLinebreak, after: endOfLine),
+ formatter.tokens[nextIndex] == .operator(".", .infix),
+ // Make sure to preserve any code comment between the two lines
+ let nextTokenOrComment = formatter.index(of: .nonSpaceOrLinebreak, after: endOfLine)
+ {
+ let startOfLine = formatter.startOfLine(at: nextTokenOrComment)
  formatter.removeTokens(in: endOfLine + 1 ..< startOfLine)
  }
  }

Tests/RulesTests+Linebreaks.swift

@@ -394,6 +394,23 @@ class LinebreakTests: RulesTests {
  testFormatting(for: input, [output1, output2], rules: [FormatRules.blankLinesBetweenChainedFunctions])
  }
 
+ func testBlankLinesWithCommentsBetweenChainedFunctions() {
+ let input = """
+ [0, 1, 2]
+ .map { $0 * 2 }
+
+ // Multiplies by 3
+ .map { $0 * 3 }
+ """
+ let output = """
+ [0, 1, 2]
+ .map { $0 * 2 }
+ // Multiplies by 3
+ .map { $0 * 3 }
+ """
+ testFormatting(for: input, output, rule: FormatRules.blankLinesBetweenChainedFunctions)
+ }
+
  // MARK: - blankLineAfterImports
 
  func testBlankLineAfterImport() {