Add fix and tests for postfix pound ifs

Author: David Brunow

Sources/SwiftFormatPrettyPrint/TokenStreamCreator.swift

@@ -1289,7 +1289,21 @@ fileprivate final class TokenStreamCreator: SyntaxVisitor {
       before(tokenToOpenWith.nextToken, tokens: .break(breakKindClose, newlines: .soft), .close)
     }
 
-    if let condition = node.condition {
+    if let previousToken = node.previousToken,
+       node.condition?.nextToken?.text == ".",
+       (previousToken.text == ")" || previousToken.text == "}") {
+      before(
+        node.firstToken,
+        tokens: [
+          .printerControl(kind: .enableBreaking),
+          .break(.reset, size: 0),
+          .break(breakKindOpen),
+          .open,
+          .break(breakKindClose),
+          .close
+        ]
+      )
+    } else if let condition = node.condition {
       before(condition.firstToken, tokens: .printerControl(kind: .disableBreaking))
       after(
         condition.lastToken,

Tests/SwiftFormatPrettyPrintTests/IfConfigTests.swift

@@ -230,4 +230,68 @@ final class IfConfigTests: PrettyPrintTestCase {
 
     assertPrettyPrintEqual(input: input, expected: expected, linelength: 40)
   }
+
+  func testPostfixPoundIfAfterParentheses() {
+    let input =
+      """
+      VStack {
+        Text("something")
+        #if os(iOS)
+        .iOSSpecificModifier()
+        #endif
+        .commonModifier()
+      }
+      """
+
+    let expected =
+      """
+      VStack {
+        Text("something")
+        #if os(iOS)
+          .iOSSpecificModifier()
+        #endif
+        .commonModifier()
+      }
+
+      """
+
+    assertPrettyPrintEqual(input: input, expected: expected, linelength: 45)
+  }
+
+  func testPostfixPoundIfAfterClosingBrace() {
+    let input =
+      """
+      HStack {
+          Toggle(isOn: binding) {
+              Text("Some text")
+          }
+          #if !os(tvOS)
+          .toggleStyle(SwitchToggleStyle(tint: Color.blue))
+          #endif
+          .accessibilityValue(
+              binding.wrappedValue == true ? "On" : "Off"
+          )
+      }
+      """
+
+    let expected =
+      """
+      HStack {
+        Toggle(isOn: binding) {
+          Text("Some text")
+        }
+        #if !os(tvOS)
+          .toggleStyle(
+            SwitchToggleStyle(tint: Color.blue))
+        #endif
+        .accessibilityValue(
+          binding.wrappedValue == true
+            ? "On" : "Off"
+        )
+      }
+
+      """
+
+    assertPrettyPrintEqual(input: input, expected: expected, linelength: 45)
+  }
 }