Flush logs at the end of test execution

Otherwise it sometimes happens that shutdown and other messages are logged during the next test’s execution, which makes it harder to diagnose issues.

Author: ahoppen

Sources/SKTestSupport/TestSourceKitLSPClient.swift

@@ -15,6 +15,7 @@ import InProcessClient
 package import LanguageServerProtocol
 import LanguageServerProtocolExtensions
 import LanguageServerProtocolJSONRPC
+import SKLogging
 package import SKOptions
 import SKUtilities
 import SourceKitD
@@ -217,14 +218,21 @@ package final class TestSourceKitLSPClient: MessageHandler, Sendable {
   deinit {
     // It's really unfortunate that there are no async deinits. If we had async
     // deinits, we could await the sending of a ShutdownRequest.
-    let sema = WrappedSemaphore(name: "Shutdown")
+    let shutdownSemaphore = WrappedSemaphore(name: "Shutdown")
     server.handle(ShutdownRequest(), id: .number(Int(nextRequestID.fetchAndIncrement()))) { result in
-      sema.signal()
+      shutdownSemaphore.signal()
     }
-    sema.waitOrXCTFail()
+    shutdownSemaphore.waitOrXCTFail()
     self.send(ExitNotification())
 
     cleanUp()
+
+    let flushSemaphore = WrappedSemaphore(name: "Flush log")
+    Task {
+      await NonDarwinLogger.flush()
+      flushSemaphore.signal()
+    }
+    flushSemaphore.waitOrXCTFail()
   }
 
   // MARK: - Sending messages