Reduce spurious change tracking

Sources/CommandLine.swift

@@ -782,8 +782,7 @@ func applyRules(_ source: String, options: Options, lineRange: ClosedRange<Int>?
                 verbose: Bool, lint: Bool) throws -> String
 {
     // Parse source
-    let originalTokens = tokenize(source)
-    var tokens = originalTokens
+    var tokens = tokenize(source)
 
     // Get rules
     let rulesByName = FormatRules.byName
@@ -802,14 +801,15 @@ func applyRules(_ source: String, options: Options, lineRange: ClosedRange<Int>?
                                        trackChanges: lint || verbose, range: range)
 
     // Display info
-    if lint, tokens != originalTokens {
+    let updatedSource = sourceCode(for: tokens)
+    if lint, updatedSource != source {
         changes.forEach { print($0.description, as: .warning) }
     }
     if verbose {
         let rulesApplied = changes.reduce(into: Set<String>()) {
             $0.insert($1.rule.name)
         }
-        if rulesApplied.isEmpty || tokens == originalTokens {
+        if rulesApplied.isEmpty || updatedSource == source {
             print("-- no changes", as: .success)
         } else {
             let sortedNames = Array(rulesApplied).sorted().joined(separator: ", ")
@@ -818,7 +818,7 @@ func applyRules(_ source: String, options: Options, lineRange: ClosedRange<Int>?
     }
 
     // Output
-    return sourceCode(for: tokens)
+    return updatedSource
 }
 
 func processInput(_ inputURLs: [URL],

Sources/Formatter.swift

@@ -235,10 +235,10 @@ public extension Formatter {
 
     /// Replaces the token at the specified index with a new token
     func replaceToken(at index: Int, with token: Token) {
-        if token != tokens[index] {
+        if trackChanges, token.string != tokens[index].string {
             trackChange(at: index)
-            tokens[index] = token
         }
+        tokens[index] = token
     }
 
     /// Replaces the tokens in the specified range with new tokens
@@ -250,7 +250,7 @@ public extension Formatter {
         }
         if range.count > max {
             removeTokens(in: range.dropFirst(max))
-        } else {
+        } else if tokens.count > max {
             insert(tokens.dropFirst(max), at: range.lowerBound + max)
         }
         return tokens.count - range.count

Sources/Rules.swift

@@ -752,7 +752,8 @@ public struct _FormatRules {
 
     /// Remove blank lines immediately after an opening brace, bracket, paren or chevron
     public let blankLinesAtStartOfScope = FormatRule(
-        help: "Remove leading blank line at the start of a scope."
+        help: "Remove leading blank line at the start of a scope.",
+        orderAfter: ["organizeDeclarations"]
     ) { formatter in
         formatter.forEach(.startOfScope) { i, token in
             guard ["{", "(", "[", "<"].contains(token.string),
@@ -784,7 +785,8 @@ public struct _FormatRules {
     /// Remove blank lines immediately before a closing brace, bracket, paren or chevron
     /// unless it's followed by more code on the same line (e.g. } else { )
     public let blankLinesAtEndOfScope = FormatRule(
-        help: "Remove trailing blank line at the end of a scope."
+        help: "Remove trailing blank line at the end of a scope.",
+        orderAfter: ["organizeDeclarations"]
     ) { formatter in
         formatter.forEach(.endOfScope) { i, token in
             guard ["}", ")", "]", ">"].contains(token.string),
@@ -5322,12 +5324,6 @@ public struct _FormatRules {
             .map { organize($0) }
 
         let updatedTokens = organizedDeclarations.flatMap { $0.tokens }
-
-        if sourceCode(for: formatter.tokens) != sourceCode(for: updatedTokens) {
-            formatter.replaceTokens(
-                in: 0 ..< formatter.tokens.count,
-                with: updatedTokens
-            )
-        }
+        formatter.replaceTokens(in: 0 ..< formatter.tokens.count, with: updatedTokens)
     }
 }

Tests/FormatterTests.swift

@@ -441,4 +441,15 @@ class FormatterTests: XCTestCase {
         """))
         XCTAssertEqual(formatter.endOfScope(at: 4), 13)
     }
+
+    // MARK: change tracking
+
+    func testTrackChangesIgnoresLinebreakIndex() {
+        let formatter = Formatter(tokenize("\n\n"), trackChanges: true)
+        var tokens = formatter.tokens
+        tokens.insert(tokens.removeLast(), at: 0)
+        XCTAssertNotEqual(formatter.tokens, tokens)
+        formatter.replaceTokens(in: 0 ..< 2, with: tokens)
+        XCTAssert(formatter.changes.isEmpty)
+    }
 }

Tests/RulesTests.swift

@@ -13239,10 +13239,10 @@ class RulesTests: XCTestCase {
         let input = """
         public class Foo {
             public class Bar {
-                fileprivate func baaz()
+                fileprivate func baaz() {}
                 public var quux: Int
                 init() {}
-                deinit() {}
+                deinit {}
             }
         }
         """
@@ -13255,7 +13255,7 @@ class RulesTests: XCTestCase {
                 // MARK: Lifecycle
 
                 init() {}
-                deinit() {}
+                deinit {}
 
                 // MARK: Public
 
@@ -13263,7 +13263,7 @@ class RulesTests: XCTestCase {
 
                 // MARK: Fileprivate
 
-                fileprivate func baaz()
+                fileprivate func baaz() {}
 
             }
 
@@ -13273,7 +13273,7 @@ class RulesTests: XCTestCase {
         testFormatting(
             for: input, output,
             rule: FormatRules.organizeDeclarations,
-            exclude: ["blankLinesAtStartOfScope", "blankLinesAtEndOfScope", "spaceAroundParens"]
+            exclude: ["blankLinesAtStartOfScope", "blankLinesAtEndOfScope"]
         )
     }
 

Tests/XCTestManifests.swift

@@ -154,6 +154,7 @@ extension FormatterTests {
         ("testRemoveNextTokenWhileEnumerating", testRemoveNextTokenWhileEnumerating),
         ("testRemovePreviousTokenWhileEnumerating", testRemovePreviousTokenWhileEnumerating),
         ("testSwiftVersionNext", testSwiftVersionNext),
+        ("testTrackChangesIgnoresLinebreakIndex", testTrackChangesIgnoresLinebreakIndex),
     ]
 }