Merge pull request #1083 from ahoppen/ahoppen/no-compiler-args-message

Show message in the client if no compiler arguments could be found for a file

Author: ahoppen

Sources/SKTestSupport/TestSourceKitLSPClient.swift

@@ -201,17 +201,28 @@ public final class TestSourceKitLSPClient: MessageHandler {
   public func nextDiagnosticsNotification(
     timeout: TimeInterval = defaultTimeout
   ) async throws -> PublishDiagnosticsNotification {
-    struct CastError: Error, CustomStringConvertible {
-      let actualType: any NotificationType.Type
+    return try await nextNotification(ofType: PublishDiagnosticsNotification.self, timeout: timeout)
+  }
 
-      var description: String { "Expected a publish diagnostics notification but got '\(actualType)'" }
-    }
+  private struct CastError: Error, CustomStringConvertible {
+    let expectedType: any NotificationType.Type
+    let actualType: any NotificationType.Type
+
+    var description: String { "Expected a \(expectedType) but got '\(actualType)'" }
+  }
 
+  /// Await the next diagnostic notification sent to the client.
+  ///
+  /// If the next notification is not of the expected type, this methods throws.
+  public func nextNotification<ExpectedNotificationType: NotificationType>(
+    ofType: ExpectedNotificationType.Type,
+    timeout: TimeInterval = defaultTimeout
+  ) async throws -> ExpectedNotificationType {
     let nextNotification = try await nextNotification(timeout: timeout)
-    guard let diagnostics = nextNotification as? PublishDiagnosticsNotification else {
-      throw CastError(actualType: type(of: nextNotification))
+    guard let notification = nextNotification as? ExpectedNotificationType else {
+      throw CastError(expectedType: ExpectedNotificationType.self, actualType: type(of: nextNotification))
     }
-    return diagnostics
+    return notification
   }
 
   /// Handle the next request that is sent to the client with the given handler.

Sources/SourceKitLSP/Swift/SwiftLanguageServer.swift

@@ -341,6 +341,22 @@ extension SwiftLanguageServer {
       return
     }
 
+    let buildSettings = await self.buildSettings(for: snapshot.uri)
+    if buildSettings == nil || buildSettings!.isFallback, let fileUrl = note.textDocument.uri.fileURL {
+      // Do not show this notification for non-file URIs to make sure we don't see this notificaiton for newly created
+      // files (which get opened as with a `untitled:Unitled-1` URI by VS Code.
+      await sourceKitServer?.sendNotificationToClient(
+        ShowMessageNotification(
+          type: .warning,
+          message: """
+            Failed to get compiler arguments for \(fileUrl.lastPathComponent).
+            Ensure the source file is part of a Swift package or has compiler arguments in compile_commands.json.
+            Functionality will be limited.
+            """
+        )
+      )
+    }
+
     let req = sourcekitd.dictionary([
       keys.request: self.requests.editorOpen,
       keys.name: note.textDocument.uri.pseudoPath,
@@ -349,7 +365,7 @@ extension SwiftLanguageServer {
       keys.enableStructure: 0,
       keys.enableDiagnostics: 0,
       keys.syntacticOnly: 1,
-      keys.compilerArgs: await self.buildSettings(for: snapshot.uri)?.compilerArgs as [SKDRequestValue]?,
+      keys.compilerArgs: buildSettings?.compilerArgs as [SKDRequestValue]?,
     ])
 
     _ = try? await self.sourcekitd.send(req, fileContents: snapshot.text)

Tests/SourceKitLSPTests/BuildSystemTests.swift

@@ -249,6 +249,7 @@ final class BuildSystemTests: XCTestCase {
     let documentManager = await self.testClient.server._documentManager
 
     testClient.openDocument(text, uri: doc)
+    _ = try await testClient.nextNotification(ofType: ShowMessageNotification.self)
     let openDiags = try await testClient.nextDiagnosticsNotification()
     XCTAssertEqual(openDiags.diagnostics.count, 1)
     XCTAssertEqual(text, try documentManager.latestSnapshot(doc).text)