Add option to blankLinesAfterGuardStatements rule to have blank line between consecutive guards (#2058)

Author: alecsmirnov

Rules.md

@@ -304,20 +304,68 @@ which is followed by a closing brace).
 
 Remove blank lines between consecutive guard statements, and insert a blank after the last guard statement.
 
+Option | Description
+--- | ---
+`--linebtwnguards` | Insert line between guards: "true" or "false" (default)
+
 <details>
 <summary>Examples</summary>
 
+`--linebtwnguards false` (default)
+
 ```diff
+    // Multiline guard
     guard let spicy = self.makeSpicy() else {
         return
+    } 
+-
+    guard let yummy = self.makeYummy() else {
+        return
+    }
+    guard let soap = self.clean() else {
+        return
     }
++
+    let doTheJob = nikekov()
+```
+```diff
+    // Single-line guard
+    guard let spicy = self.makeSpicy() else { return }
 -
+    guard let yummy = self.makeYummy() else { return }
+    guard let soap = self.clean() else { return }
++
+    let doTheJob = nikekov()
+```
+
+`--linebtwnguards true`
+
+```diff
+    // Multiline guard
+    guard let spicy = self.makeSpicy() else {
+        return
+    }
+
+    guard let yummy = self.makeYummy() else {
+        return
+    }
++
     guard let soap = self.clean() else {
         return
     }
 +
     let doTheJob = nikekov()
 ```
+```diff
+    // Single-line guard
+    guard let spicy = self.makeSpicy() else { return }
+
+    guard let yummy = self.makeYummy() else { return }
++
+    guard let soap = self.clean() else { return }
++
+    let doTheJob = nikekov()
+```
 
 </details>
 <br/>

Sources/OptionDescriptor.swift

@@ -1279,6 +1279,14 @@ struct _Descriptors {
         trueValues: ["#file", "file"],
         falseValues: ["#fileID", "fileID"]
     )
+    let lineBetweenConsecutiveGuards = OptionDescriptor(
+        argumentName: "linebtwnguards",
+        displayName: "Blank Line Between Consecutive Guards",
+        help: "Insert line between guards: \"true\" or \"false\" (default)",
+        keyPath: \.lineBetweenConsecutiveGuards,
+        trueValues: ["true"],
+        falseValues: ["false"]
+    )
 
     // MARK: - Internal
 

Sources/Options.swift

@@ -748,6 +748,7 @@ public struct FormatOptions: CustomStringConvertible {
     public var additionalXCTestSymbols: Set<String>
     public var equatableMacro: EquatableMacro
     public var preferFileMacro: Bool
+    public var lineBetweenConsecutiveGuards: Bool
 
     /// Deprecated
     public var indentComments: Bool
@@ -879,6 +880,7 @@ public struct FormatOptions: CustomStringConvertible {
                 additionalXCTestSymbols: Set<String> = [],
                 equatableMacro: EquatableMacro = .none,
                 preferFileMacro: Bool = true,
+                lineBetweenConsecutiveGuards: Bool = false,
                 // Doesn't really belong here, but hard to put elsewhere
                 fragment: Bool = false,
                 ignoreConflictMarkers: Bool = false,
@@ -1000,6 +1002,7 @@ public struct FormatOptions: CustomStringConvertible {
         self.additionalXCTestSymbols = additionalXCTestSymbols
         self.equatableMacro = equatableMacro
         self.preferFileMacro = preferFileMacro
+        self.lineBetweenConsecutiveGuards = lineBetweenConsecutiveGuards
         // Doesn't really belong here, but hard to put elsewhere
         self.fragment = fragment
         self.ignoreConflictMarkers = ignoreConflictMarkers

Sources/Rules/BlankLinesAfterGuardStatements.swift

@@ -6,7 +6,8 @@ import Foundation
 public extension FormatRule {
     static let blankLinesAfterGuardStatements = FormatRule(
         help: "Remove blank lines between consecutive guard statements, and insert a blank after the last guard statement.",
-        disabledByDefault: true
+        disabledByDefault: true,
+        options: ["linebtwnguards"]
     ) { formatter in
         formatter.forEach(.keyword("guard")) { guardIndex, _ in
             guard var elseIndex = formatter.index(of: .keyword("else"), after: guardIndex) else {
@@ -34,23 +35,73 @@ public extension FormatRule {
                 return
             }
 
-            let linebreaks = nextToken == .keyword("guard") ? 1 : 2
+            let linebreaks: Int
+            if formatter.options.lineBetweenConsecutiveGuards {
+                linebreaks = 2
+            } else {
+                linebreaks = nextToken == .keyword("guard") ? 1 : 2
+            }
+
             let indexesBetween = Set(endOfGuardScope + 1 ..< nextNonSpaceAndNonLinebreakIndex)
             formatter.leaveOrSetLinebreaksInIndexes(indexesBetween, linebreaksCount: linebreaks)
         }
     } examples: {
         """
+        `--linebtwnguards false` (default)
+
         ```diff
+            // Multiline guard
             guard let spicy = self.makeSpicy() else {
                 return
+            } 
+        -
+            guard let yummy = self.makeYummy() else {
+                return
+            }
+            guard let soap = self.clean() else {
+                return
             }
+        +
+            let doTheJob = nikekov()
+        ```
+        ```diff
+            // Single-line guard
+            guard let spicy = self.makeSpicy() else { return }
         -
+            guard let yummy = self.makeYummy() else { return }
+            guard let soap = self.clean() else { return }
+        +
+            let doTheJob = nikekov()
+        ```
+
+        `--linebtwnguards true`
+
+        ```diff
+            // Multiline guard
+            guard let spicy = self.makeSpicy() else {
+                return
+            }
+
+            guard let yummy = self.makeYummy() else {
+                return
+            }
+        +
             guard let soap = self.clean() else {
                 return
             }
         +
             let doTheJob = nikekov()
         ```
+        ```diff
+            // Single-line guard
+            guard let spicy = self.makeSpicy() else { return }
+
+            guard let yummy = self.makeYummy() else { return }
+        +
+            guard let soap = self.clean() else { return }
+        +
+            let doTheJob = nikekov()
+        ```
         """
     }
 }