BasicFormat should add spacing around { and }

We now properly strip trailing whitespace. Add in spacing after `{` and
before `}`.

Author: bnbarham

Sources/SwiftBasicFormat/BasicFormat.swift

@@ -213,7 +213,7 @@ open class BasicFormat: SyntaxRewriter {
       (.keyword(.set), .leftParen),  // var mYar: Int { set(value) {} }
       (.keyword(.subscript), .leftParen),  // subscript(x: Int)
       (.keyword(.super), .period),  // super.someProperty
-      (.leftBrace, _),
+      (.leftBrace, .rightBrace), // {}
       (.leftParen, _),
       (.leftSquareBracket, _),
       (.multilineStringQuote, .rawStringDelimiter),  // closing raw string delimiter should never be separate by a space
@@ -245,7 +245,6 @@ open class BasicFormat: SyntaxRewriter {
       (_, .exclamationMark),
       (_, .postfixOperator),
       (_, .postfixQuestionMark),
-      (_, .rightBrace),
       (_, .rightParen),
       (_, .rightSquareBracket),
       (_, .semicolon),

Tests/SwiftBasicFormatTest/BasicFormatTests.swift

@@ -327,4 +327,18 @@ final class BasicFormatTest: XCTestCase {
       using: BasicFormat(indentationWidth: .spaces(2))
     )
   }
+
+  func testClosureExprParam() {
+    let source = """
+      _ = {foo in}
+      """
+
+    assertFormatted(
+      source: source,
+      expected: """
+        _ = { foo in
+        }
+        """
+    )
+  }
 }

Tests/SwiftParserTest/ExpressionTests.swift

@@ -1897,7 +1897,7 @@ final class StatementExpressionTests: XCTestCase {
       ],
       fixedSource: #"""
         """
-        \({(<#expression#>)})
+        \({(<#expression#>) })
         """
         """#
     )

Tests/SwiftParserTest/translated/ForeachAsyncTests.swift

@@ -138,7 +138,7 @@ final class ForeachAsyncTests: XCTestCase {
       fixedSource: """
         func for_each(r: AsyncRange<Int>, iir: AsyncIntRange<Int>) async {
           var sum = 0
-          for await i in r {sum = sum + i;
+          for await i in r { sum = sum + i;
         }
         }
         """

Tests/SwiftParserTest/translated/ForeachTests.swift

@@ -102,7 +102,7 @@ final class ForeachTests: XCTestCase {
       fixedSource: """
         func for_each(r: Range<Int>, iir: IntRange<Int>) {
           var sum = 0
-          for i in r {sum = sum + i;
+          for i in r { sum = sum + i;
         }
         }
         """

Tests/SwiftParserTest/translated/RecoveryTests.swift

@@ -2348,7 +2348,7 @@ final class RecoveryTests: XCTestCase {
         ),
       ],
       fixedSource: """
-        func F() { init< >()} )}
+        func F() { init< >() } )}
         struct InitializerWithName {
           init() {}
         }

Tests/SwiftSyntaxBuilderTest/ClosureExprTests.swift

@@ -29,7 +29,7 @@ final class ClosureExprTests: XCTestCase {
     assertBuildResult(
       buildable,
       """
-      {area in
+      { area in
       }
       """
     )
@@ -52,7 +52,7 @@ final class ClosureExprTests: XCTestCase {
     assertBuildResult(
       buildable,
       """
-      {area async throws in
+      { area async throws in
       }
       """
     )