A return followed by default has no expression associated with it

Sources/SwiftCompilerSupport/ConsistencyCheck.swift

@@ -73,7 +73,7 @@ public func _parserConsistencyCheck(
           continue
         }
 
-        print("\(diag.debugDescription)")
+        print("\(String(cString: filename)): error: \(diag.debugDescription)")
         anyDiags = true
       }
 

Sources/SwiftParser/Statements.swift

@@ -865,7 +865,7 @@ extension Parser {
     let expr: RawExprSyntax?
     if
       !self.at(any: [
-        .rightBrace, .caseKeyword, .semicolon, .eof,
+        .rightBrace, .caseKeyword, .defaultKeyword, .semicolon, .eof,
         .poundIfKeyword, .poundErrorKeyword, .poundWarningKeyword,
         .poundEndifKeyword, .poundElseKeyword, .poundElseifKeyword
       ])

Tests/SwiftParserTest/ParserTests.swift

@@ -33,7 +33,7 @@ public class ParserTests: XCTestCase {
     }
   }
 
-  /// Run parsr tests on all of the Swift files in the
+  /// Run parsr tests on all of the Swift files in the given path, recursively.
   func runParserTests(
     name: String, path: URL, checkDiagnostics: Bool,
     shouldExclude: (URL) -> Bool = { _ in false }
@@ -76,6 +76,9 @@ public class ParserTests: XCTestCase {
     )
   }
 
+  /// Test all of the files in the "test" directory of the main Swift compiler.
+  /// This requires the Swift compiler to have been checked out into the "swift"
+  /// directory alongside swift-syntax.
   func testSwiftTestsuite() throws {
     try XCTSkipIf(ProcessInfo.processInfo.environment["SKIP_SELF_PARSE"] == "1")
     let testDir = URL(fileURLWithPath: #file)
@@ -97,6 +100,9 @@ public class ParserTests: XCTestCase {
     )
   }
 
+  /// Test all of the files in the "validation-text" directory of the main
+  /// Swift compiler. This requires the Swift compiler to have been checked
+  /// out into the "swift" directory alongside swift-syntax.
   func testSwiftValidationTestsuite() throws {
     try XCTSkipIf(ProcessInfo.processInfo.environment["SKIP_SELF_PARSE"] == "1")
     let testDir = URL(fileURLWithPath: #file)
@@ -139,6 +145,7 @@ public class ParserTests: XCTestCase {
         || fileURL.absoluteString.contains("26101-swift-parser-parsenewdeclattribute.swift")
         || fileURL.absoluteString.contains("26773-swift-diagnosticengine-diagnose.swift")
         || fileURL.absoluteString.contains("parser-cutoff.swift")
+        || fileURL.absoluteString.contains("26233-swift-iterabledeclcontext-getmembers.swift")
       }
     )
   }

Tests/SwiftParserTest/Statements.swift

@@ -110,6 +110,21 @@ final class StatementTests: XCTestCase {
     )
 
     AssertParse("return true ? nil : nil")
+
+    AssertParse(
+      """
+      switch command {
+      case .start:
+        break
+
+      case .stop:
+        return
+
+      default:
+        break
+      }
+      """
+    )
   }
 
   func testSwitch() {