Absorb trailing comma of function call args in grouped exprs.

Previously, these trailing commas could be placed on a new line after the expression because the close break after the expression would fire if the comma landed exactly 1 over the column limit. Now the comma is moved inside of the group and breaks around the expr so that a break inside of the expr fires instead of the close break.

Author: dylansturg

Sources/SwiftFormatPrettyPrint/TokenStreamCreator.swift

@@ -837,6 +837,9 @@ fileprivate final class TokenStreamCreator: SyntaxVisitor {
 
     let shouldGroupAroundArgument = !isCompactSingleFunctionCallArgument(arguments)
     for argument in arguments {
+      if let trailingComma = argument.trailingComma {
+        closingDelimiterTokens.insert(trailingComma)
+      }
       arrangeAsFunctionCallArgument(argument, shouldGroup: shouldGroupAroundArgument)
     }
   }

Tests/SwiftFormatPrettyPrintTests/FunctionCallTests.swift

@@ -249,4 +249,25 @@ final class FunctionCallTests: PrettyPrintTestCase {
 
     assertPrettyPrintEqual(input: input, expected: expected, linelength: 20)
   }
+
+  func testGroupsTrailingComma() {
+    let input =
+      """
+      foo(
+        image: useLongName ? image(named: .longNameImage) : image(named: .veryLongNameImageZ),
+        bar: bar)
+      """
+
+    let expected =
+      """
+      foo(
+        image: useLongName
+          ? image(named: .longNameImage)
+          : image(named: .veryLongNameImageZ),
+        bar: bar)
+
+      """
+
+    assertPrettyPrintEqual(input: input, expected: expected, linelength: 70)
+  }
 }

Tests/SwiftFormatPrettyPrintTests/ObjectLiteralExprTests.swift

@@ -110,4 +110,25 @@ final class ObjectLiteralExprTests: PrettyPrintTestCase {
     config.lineBreakBeforeEachArgument = false
     assertPrettyPrintEqual(input: input, expected: expected, linelength: 38, configuration: config)
   }
+
+  func testGroupsTrailingComma() {
+    let input =
+      """
+      #imageLiteral(
+        image: useLongName ? image(named: .longNameImage) : image(named: .veryLongNameImageZ),
+        bar: bar)
+      """
+
+    let expected =
+      """
+      #imageLiteral(
+        image: useLongName
+          ? image(named: .longNameImage)
+          : image(named: .veryLongNameImageZ),
+        bar: bar)
+
+      """
+
+    assertPrettyPrintEqual(input: input, expected: expected, linelength: 70)
+  }
 }

Tests/SwiftFormatPrettyPrintTests/SubscriptExprTests.swift

@@ -85,4 +85,25 @@ final class SubscriptExprTests: PrettyPrintTestCase {
 
     assertPrettyPrintEqual(input: input, expected: expected, linelength: 45)
   }
+
+  func testGroupsTrailingComma() {
+    let input =
+      """
+      myCollection[
+        image: useLongName ? image(named: .longNameImage) : image(named: .veryLongNameImageZ),
+        bar: bar]
+      """
+
+    let expected =
+      """
+      myCollection[
+        image: useLongName
+          ? image(named: .longNameImage)
+          : image(named: .veryLongNameImageZ),
+        bar: bar]
+
+      """
+
+    assertPrettyPrintEqual(input: input, expected: expected, linelength: 70)
+  }
 }

Tests/SwiftFormatPrettyPrintTests/XCTestManifests.swift

@@ -270,6 +270,7 @@ extension FunctionCallTests {
         ("testBasicFunctionCalls_packArguments", testBasicFunctionCalls_packArguments),
         ("testDiscretionaryLineBreakBeforeClosingParenthesis", testDiscretionaryLineBreakBeforeClosingParenthesis),
         ("testDiscretionaryLineBreaksAreSelfCorrecting", testDiscretionaryLineBreaksAreSelfCorrecting),
+        ("testGroupsTrailingComma", testGroupsTrailingComma),
         ("testIgnoresDiscretionaryLineBreakAfterColon", testIgnoresDiscretionaryLineBreakAfterColon),
         ("testNestedFunctionCallExprSequences", testNestedFunctionCallExprSequences),
         ("testSingleUnlabeledArgumentWithDelimiters", testSingleUnlabeledArgumentWithDelimiters),
@@ -473,6 +474,7 @@ extension ObjectLiteralExprTests {
     static let __allTests__ObjectLiteralExprTests = [
         ("testColorLiteral_noPackArguments", testColorLiteral_noPackArguments),
         ("testColorLiteral_packArguments", testColorLiteral_packArguments),
+        ("testGroupsTrailingComma", testGroupsTrailingComma),
         ("testImageLiteral_noPackArguments", testImageLiteral_noPackArguments),
         ("testImageLiteral_packArguments", testImageLiteral_packArguments),
     ]
@@ -660,6 +662,7 @@ extension SubscriptExprTests {
     static let __allTests__SubscriptExprTests = [
         ("testBasicSubscriptGetters", testBasicSubscriptGetters),
         ("testBasicSubscriptSetters", testBasicSubscriptSetters),
+        ("testGroupsTrailingComma", testGroupsTrailingComma),
         ("testSubscriptGettersWithTrailingClosures", testSubscriptGettersWithTrailingClosures),
         ("testSubscriptSettersWithTrailingClosures", testSubscriptSettersWithTrailingClosures),
     ]