Merge pull request #21 from allevato/sr-11169

Improve method chaining, especially involving trailing closures.

Sources/SwiftFormatPrettyPrint/PrettyPrint.swift

@@ -210,7 +210,6 @@ public class PrettyPrinter {
       switch kind {
       case .open:
         continuationStack.append(currentLineIsContinuation)
-        isContinuationIfBreakFires = false
         openDelimiterBreakStack.append(lineNumber)
 
         // If an open break occurs on a continuation line, we must push that continuation
@@ -222,16 +221,22 @@ public class PrettyPrinter {
         }
 
         indentationStack.append(configuration.indentation)
+
+        // Once we've reached an open break and preserved the continuation state, the "scope" we now
+        // enter is *not* a continuation scope. If it was one, we'll re-enter it when we reach the
+        // corresponding close.
+        currentLineIsContinuation = false
+
       case .close(let closeMustBreak):
         guard let matchingOpenLineNumber = openDelimiterBreakStack.popLast() else {
           fatalError("Unmatched closing break")
         }
 
         indentationStack.removeLast()
-        isContinuationIfBreakFires = continuationStack.popLast() ?? false
+        let wasContinuationWhenOpened = continuationStack.popLast() ?? false
 
         // Un-persist any continuation indentation that may have applied to the open/close scope.
-        if isContinuationIfBreakFires {
+        if wasContinuationWhenOpened {
           indentationStack.removeLast()
         }
 
@@ -268,12 +273,18 @@ public class PrettyPrinter {
           //
           // Likewise, we need to do this if we popped an old continuation state off the stack,
           // even if the break *doesn't* fire.
-          currentLineIsContinuation = isContinuationIfBreakFires || isDifferentLine
+          currentLineIsContinuation = isDifferentLine
         }
+
+        // Restore the continuation state of the scope we were in before the open break occurred.
+        currentLineIsContinuation = currentLineIsContinuation || wasContinuationWhenOpened
+
       case .continue:
         isContinuationIfBreakFires = true
+
       case .same:
         break
+
       case .reset:
         mustBreak = currentLineIsContinuation
       }

Sources/SwiftFormatPrettyPrint/TokenStreamCreator.swift

@@ -631,7 +631,7 @@ private final class TokenStreamCreator: SyntaxVisitor {
       before(
         node.rightParen, tokens: .break(.close(mustBreak: breakBeforeRightParen), size: 0), .close)
     }
-    before(node.trailingClosure?.leftBrace, tokens: .break(.reset))
+    before(node.trailingClosure?.leftBrace, tokens: .break(.same))
     return .visitChildren
   }
 

Tests/SwiftFormatPrettyPrintTests/MemberAccessExprTests.swift

@@ -39,4 +39,42 @@ public class MemberAccessExprTests: PrettyPrintTestCase {
 
     assertPrettyPrintEqual(input: input, expected: expected, linelength: 15)
   }
+
+  public func testMethodChainingWithClosures() {
+    let input =
+      """
+      let result = [1, 2, 3, 4, 5]
+          .filter{$0 % 2 == 0}
+          .map{$0 * $0}
+      """
+
+    let expected =
+      """
+      let result = [1, 2, 3, 4, 5]
+        .filter { $0 % 2 == 0 }
+        .map { $0 * $0 }
+
+      """
+
+    assertPrettyPrintEqual(input: input, expected: expected, linelength: 30)
+  }
+
+  public func testMethodChainingWithClosuresFullWrap() {
+    let input =
+      """
+      let result = [1, 2, 3, 4, 5].filter { $0 % 2 == 0 }.map { $0 * $0 }
+      """
+
+    let expected =
+      """
+      let result = [
+        1, 2, 3, 4, 5
+      ].filter {
+        $0 % 2 == 0
+      }.map { $0 * $0 }
+
+      """
+
+    assertPrettyPrintEqual(input: input, expected: expected, linelength: 20)
+  }
 }

Tests/SwiftFormatPrettyPrintTests/XCTestManifests.swift

@@ -300,6 +300,8 @@ extension MemberAccessExprTests {
     static let __allTests__MemberAccessExprTests = [
         ("testImplicitMemberAccess", testImplicitMemberAccess),
         ("testMemberAccess", testMemberAccess),
+        ("testMethodChainingWithClosures", testMethodChainingWithClosures),
+        ("testMethodChainingWithClosuresFullWrap", testMethodChainingWithClosuresFullWrap),
     ]
 }