Add --blank-line-after-switch-case always option to blankLineAfterSwitchCase rule (#2150)

Rules.md

@@ -277,12 +277,18 @@ Insert blank line after import statements.
 
 ## blankLineAfterSwitchCase
 
-Insert a blank line after multiline switch cases (excluding the last case,
+Insert a blank line after switch cases (excluding the last case,
 which is followed by a closing brace).
 
+Option | Description
+--- | ---
+`--blank-line-after-switch-case` | Insert line After switch cases: "always" or "multiline-only" (default)
+
 <details>
 <summary>Examples</summary>
 
+`--blank-line-after-switch-case multiline-only` (default)
+
 ```diff
   func handle(_ action: SpaceshipAction) {
       switch action {
@@ -304,6 +310,58 @@ which is followed by a closing brace).
   }
 ```
 
+```diff
+  func handle(_ action: SpaceshipAction) {
+      switch action {
+      case .engageWarpDrive:
+          warpDrive.activate()
+
+      case let .scanPlanet(planet):
+          scanner.scanForArticialLife()
+
+      case .handleIncomingEnergyBlast:
+          energyShields.engage()
+      }
+  }
+```
+`--blank-line-after-switch-case always` 
+
+```diff
+  func handle(_ action: SpaceshipAction) {
+      switch action {
+      case .engageWarpDrive:
+          navigationComputer.destination = targetedDestination
+          await warpDrive.spinUp()
+          warpDrive.activate()
++
+      case let .scanPlanet(planet):
+          scanner.target = planet
+          scanner.scanAtmosphere()
+          scanner.scanBiosphere()
+          scanner.scanForArticialLife()
++
+      case .handleIncomingEnergyBlast:
+          await energyShields.prepare()
+          energyShields.engage()
+      }
+  }
+```
+
+```diff
+  func handle(_ action: SpaceshipAction) {
+      switch action {
+      case .engageWarpDrive:
+          warpDrive.activate()
++
+      case let .scanPlanet(planet):
+          scanner.scanForArticialLife()
++
+      case .handleIncomingEnergyBlast:
+          energyShields.engage()
+      }
+  }
+```
+
 </details>
 <br/>
 

Sources/OptionDescriptor.swift

@@ -1347,6 +1347,12 @@ struct _Descriptors {
         trueValues: ["true"],
         falseValues: ["false"]
     )
+    let blankLineAfterSwitchCase = OptionDescriptor(
+        argumentName: "blank-line-after-switch-case",
+        displayName: "Blank Line After Switch Cases",
+        help: "Insert line After switch cases: \"always\" or \"multiline-only\" (default)",
+        keyPath: \.blankLineAfterSwitchCase
+    )
 
     // MARK: - Internal
 

Sources/Options.swift

@@ -647,6 +647,13 @@ public enum EquatableMacro: Equatable, RawRepresentable, CustomStringConvertible
     }
 }
 
+public enum BlankLineAfterSwitchCase: String, CaseIterable {
+    /// Add blank lines after multiline switch cases only
+    case multilineOnly = "multiline-only"
+    /// Always add blank lines after switch cases
+    case always
+}
+
 public enum URLMacro: Equatable, RawRepresentable, CustomStringConvertible {
     /// No URL macro
     case none
@@ -795,6 +802,7 @@ public struct FormatOptions: CustomStringConvertible {
     public var urlMacro: URLMacro
     public var preferFileMacro: Bool
     public var lineBetweenConsecutiveGuards: Bool
+    public var blankLineAfterSwitchCase: BlankLineAfterSwitchCase
 
     /// Deprecated
     public var indentComments: Bool
@@ -928,6 +936,7 @@ public struct FormatOptions: CustomStringConvertible {
                 urlMacro: URLMacro = .none,
                 preferFileMacro: Bool = true,
                 lineBetweenConsecutiveGuards: Bool = false,
+                blankLineAfterSwitchCase: BlankLineAfterSwitchCase = .multilineOnly,
                 // Doesn't really belong here, but hard to put elsewhere
                 fragment: Bool = false,
                 ignoreConflictMarkers: Bool = false,
@@ -1050,7 +1059,7 @@ public struct FormatOptions: CustomStringConvertible {
         self.urlMacro = urlMacro
         self.preferFileMacro = preferFileMacro
         self.lineBetweenConsecutiveGuards = lineBetweenConsecutiveGuards
-        // Doesn't really belong here, but hard to put elsewhere
+        self.blankLineAfterSwitchCase = blankLineAfterSwitchCase
         self.indentComments = indentComments
         self.fragment = fragment
         self.ignoreConflictMarkers = ignoreConflictMarkers

Sources/Rules/BlankLineAfterSwitchCase.swift

@@ -11,19 +11,22 @@ import Foundation
 public extension FormatRule {
     static let blankLineAfterSwitchCase = FormatRule(
         help: """
-        Insert a blank line after multiline switch cases (excluding the last case,
+        Insert a blank line after switch cases (excluding the last case,
         which is followed by a closing brace).
         """,
         disabledByDefault: true,
-        orderAfter: [.redundantBreak]
+        orderAfter: [.redundantBreak],
+        options: ["blank-line-after-switch-case"]
     ) { formatter in
         formatter.forEach(.keyword("switch")) { switchIndex, _ in
             guard let switchCases = formatter.switchStatementBranchesWithSpacingInfo(at: switchIndex) else { return }
 
+            let shouldAlwaysInsertBlankLineAfterSwitchCase = formatter.options.blankLineAfterSwitchCase == .always
             for switchCase in switchCases.reversed() {
-                // Any switch statement that spans multiple lines should be followed by a blank line
+                // Any switch statement should be followed by a blank line, depending on the
+                // `blankLineAfterSwitchCase` option.
                 // (excluding the last case, which is followed by a closing brace).
-                if switchCase.spansMultipleLines,
+                if shouldAlwaysInsertBlankLineAfterSwitchCase || switchCase.spansMultipleLines,
                    !switchCase.isLastCase,
                    !switchCase.isFollowedByBlankLine
                 {
@@ -41,6 +44,8 @@ public extension FormatRule {
         }
     } examples: {
         #"""
+        `--blank-line-after-switch-case multiline-only` (default)
+
         ```diff
           func handle(_ action: SpaceshipAction) {
               switch action {
@@ -61,6 +66,58 @@ public extension FormatRule {
               }
           }
         ```
+
+        ```diff
+          func handle(_ action: SpaceshipAction) {
+              switch action {
+              case .engageWarpDrive:
+                  warpDrive.activate()
+
+              case let .scanPlanet(planet):
+                  scanner.scanForArticialLife()
+
+              case .handleIncomingEnergyBlast:
+                  energyShields.engage()
+              }
+          }
+        ```
+        `--blank-line-after-switch-case always` 
+
+        ```diff
+          func handle(_ action: SpaceshipAction) {
+              switch action {
+              case .engageWarpDrive:
+                  navigationComputer.destination = targetedDestination
+                  await warpDrive.spinUp()
+                  warpDrive.activate()
+        +
+              case let .scanPlanet(planet):
+                  scanner.target = planet
+                  scanner.scanAtmosphere()
+                  scanner.scanBiosphere()
+                  scanner.scanForArticialLife()
+        +
+              case .handleIncomingEnergyBlast:
+                  await energyShields.prepare()
+                  energyShields.engage()
+              }
+          }
+        ```
+
+        ```diff
+          func handle(_ action: SpaceshipAction) {
+              switch action {
+              case .engageWarpDrive:
+                  warpDrive.activate()
+        +
+              case let .scanPlanet(planet):
+                  scanner.scanForArticialLife()
+        +
+              case .handleIncomingEnergyBlast:
+                  energyShields.engage()
+              }
+          }
+        ```
         """#
     }
 }

Tests/Rules/BlankLineAfterSwitchCaseTests.swift

@@ -46,6 +46,39 @@ class BlankLineAfterSwitchCaseTests: XCTestCase {
         testFormatting(for: input, output, rule: .blankLineAfterSwitchCase)
     }
 
+    func testAddsBlankLineAfterSingleSwitchCasesWhenBlankLineAroundSingleLineCases() {
+        let input = """
+        func handle(_ action: SpaceshipAction) {
+            switch action {
+            // The warp drive can be engaged by pressing a button on the control panel
+            case .engageWarpDrive:
+                warpDrive.activate()
+            // Triggered automatically whenever we detect an energy blast was fired in our direction
+            case .handleIncomingEnergyBlast:
+                energyShields.engage()
+            }
+        }
+        """
+
+        let output = """
+        func handle(_ action: SpaceshipAction) {
+            switch action {
+            // The warp drive can be engaged by pressing a button on the control panel
+            case .engageWarpDrive:
+                warpDrive.activate()
+
+            // Triggered automatically whenever we detect an energy blast was fired in our direction
+            case .handleIncomingEnergyBlast:
+                energyShields.engage()
+            }
+        }
+        """
+        testFormatting(for: input,
+                       output,
+                       rule: .blankLineAfterSwitchCase,
+                       options: FormatOptions(blankLineAfterSwitchCase: .always))
+    }
+
     func testRemovesBlankLineAfterLastSwitchCase() {
         let input = """
         func handle(_ action: SpaceshipAction) {