Use pull diagnostics by default in tests

Currently, all tests send publish diagnostics notifications, which is noise in the logs for most tests. Change the tests to use the pull diagnostics model by default and make the push diagnostic model opt-in.

rdar://123241539

Author: ahoppen

Sources/LanguageServerProtocol/SupportTypes/ClientCapabilities.swift

@@ -633,6 +633,11 @@ public struct TextDocumentClientCapabilities: Hashable, Codable {
 
     /// Whether the clients supports related documents for document diagnostic pulls.
     public var relatedDocumentSupport: Bool?
+
+    public init(dynamicRegistration: Bool? = nil, relatedDocumentSupport: Bool? = nil) {
+      self.dynamicRegistration = dynamicRegistration
+      self.relatedDocumentSupport = relatedDocumentSupport
+    }
   }
 
   // MARK: Properties

Sources/SKTestSupport/MultiFileTestWorkspace.swift

@@ -70,6 +70,7 @@ public class MultiFileTestWorkspace {
   public init(
     files: [RelativeFileLocation: String],
     workspaces: (URL) -> [WorkspaceFolder] = { [WorkspaceFolder(uri: DocumentURI($0))] },
+    usePullDiagnostics: Bool = true,
     testName: String = #function
   ) async throws {
     scratchDirectory = try testScratchDir(testName: testName)
@@ -103,6 +104,7 @@ public class MultiFileTestWorkspace {
     self.fileData = fileData
 
     self.testClient = try await TestSourceKitLSPClient(
+      usePullDiagnostics: usePullDiagnostics,
       workspaceFolders: workspaces(scratchDirectory),
       cleanUp: { [scratchDirectory] in
         if cleanScratchDirectories {

Sources/SKTestSupport/SwiftPMTestWorkspace.swift

@@ -40,6 +40,7 @@ public class SwiftPMTestWorkspace: MultiFileTestWorkspace {
     manifest: String = SwiftPMTestWorkspace.defaultPackageManifest,
     workspaces: (URL) -> [WorkspaceFolder] = { [WorkspaceFolder(uri: DocumentURI($0))] },
     build: Bool = false,
+    usePullDiagnostics: Bool = true,
     testName: String = #function
   ) async throws {
     var filesByPath: [RelativeFileLocation: String] = [:]
@@ -60,6 +61,7 @@ public class SwiftPMTestWorkspace: MultiFileTestWorkspace {
     try await super.init(
       files: filesByPath,
       workspaces: workspaces,
+      usePullDiagnostics: usePullDiagnostics,
       testName: testName
     )
 

Sources/SKTestSupport/TestSourceKitLSPClient.swift

@@ -46,6 +46,13 @@ public final class TestSourceKitLSPClient: MessageHandler {
   /// The server that handles the requests.
   public let server: SourceKitServer
 
+  /// Whether pull or push-model diagnostics should be used.
+  ///
+  /// This is used to fail the `nextDiagnosticsNotification` function early in case the pull-diagnostics model is used
+  /// to avoid a fruitful debug for why no diagnostic request is being sent push diagnostics have been explicitly
+  /// disabled.
+  private let usePullDiagnostics: Bool
+
   /// The connection via which the server sends requests and notifications to us.
   private let serverToClientConnection: LocalConnection
 
@@ -74,6 +81,7 @@ public final class TestSourceKitLSPClient: MessageHandler {
   ///     `true` by default
   ///   - initializationOptions: Initialization options to pass to the SourceKit-LSP server.
   ///   - capabilities: The test client's capabilities.
+  ///   - usePullDiagnostics: Whether to use push diagnostics or use push-based diagnostics
   ///   - workspaceFolders: Workspace folders to open.
   ///   - cleanUp: A closure that is called when the `TestSourceKitLSPClient` is destructed.
   ///     This allows e.g. a `IndexedSingleSwiftFileWorkspace` to delete its temporary files when they are no longer
@@ -84,6 +92,7 @@ public final class TestSourceKitLSPClient: MessageHandler {
     initialize: Bool = true,
     initializationOptions: LSPAny? = nil,
     capabilities: ClientCapabilities = ClientCapabilities(),
+    usePullDiagnostics: Bool = true,
     workspaceFolders: [WorkspaceFolder]? = nil,
     cleanUp: @escaping () -> Void = {}
   ) async throws {
@@ -115,8 +124,28 @@ public final class TestSourceKitLSPClient: MessageHandler {
     )
 
     self.cleanUp = cleanUp
+    self.usePullDiagnostics = usePullDiagnostics
     self.serverToClientConnection.start(handler: WeakMessageHandler(self))
 
+    var capabilities = capabilities
+    if usePullDiagnostics {
+      if capabilities.textDocument == nil {
+        capabilities.textDocument = TextDocumentClientCapabilities()
+      }
+      guard capabilities.textDocument!.diagnostic == nil else {
+        struct ConflictingDiagnosticsError: Error, CustomStringConvertible {
+          var description: String {
+            "usePushDiagnostics = false is not supported if capabilities already contain diagnostic options"
+          }
+        }
+        throw ConflictingDiagnosticsError()
+      }
+      capabilities.textDocument!.diagnostic = .init(dynamicRegistration: true)
+      self.handleNextRequest { (request: RegisterCapabilityRequest) in
+        XCTAssertEqual(request.registrations.only?.method, DocumentDiagnosticsRequest.method)
+        return VoidResponse()
+      }
+    }
     if initialize {
       _ = try await self.send(
         InitializeRequest(
@@ -201,6 +230,12 @@ public final class TestSourceKitLSPClient: MessageHandler {
   public func nextDiagnosticsNotification(
     timeout: TimeInterval = defaultTimeout
   ) async throws -> PublishDiagnosticsNotification {
+    guard !usePullDiagnostics else {
+      struct PushDiagnosticsError: Error, CustomStringConvertible {
+        var description = "Client is using the diagnostics and will thus never receive a diagnostics notification"
+      }
+      throw PushDiagnosticsError()
+    }
     return try await nextNotification(ofType: PublishDiagnosticsNotification.self, timeout: timeout)
   }
 

Tests/SourceKitDTests/CrashRecoveryTests.swift

@@ -48,7 +48,7 @@ final class CrashRecoveryTests: XCTestCase {
     try SkipUnless.platformIsDarwin("Linux and Windows use in-process sourcekitd")
     try SkipUnless.longTestsEnabled()
 
-    let testClient = try await TestSourceKitLSPClient()
+    let testClient = try await TestSourceKitLSPClient(usePullDiagnostics: false)
     let uri = DocumentURI.for(.swift)
 
     let positions = testClient.openDocument(

Tests/SourceKitLSPTests/BuildSystemTests.swift

@@ -90,7 +90,7 @@ final class BuildSystemTests: XCTestCase {
   private var haveClangd: Bool = false
 
   override func setUp() async throws {
-    testClient = try await TestSourceKitLSPClient()
+    testClient = try await TestSourceKitLSPClient(usePullDiagnostics: false)
     buildSystem = TestBuildSystem()
 
     let server = testClient.server

Tests/SourceKitLSPTests/CodeActionTests.swift

@@ -340,7 +340,10 @@ final class CodeActionTests: XCTestCase {
   }
 
   func testCodeActionsRemovePlaceholders() async throws {
-    let testClient = try await TestSourceKitLSPClient(capabilities: clientCapabilitiesWithCodeActionSupport())
+    let testClient = try await TestSourceKitLSPClient(
+      capabilities: clientCapabilitiesWithCodeActionSupport(),
+      usePullDiagnostics: false
+    )
     let uri = DocumentURI.for(.swift)
 
     let positions = testClient.openDocument(

Tests/SourceKitLSPTests/DependencyTrackingTests.swift

@@ -41,7 +41,8 @@ final class DependencyTrackingTests: XCTestCase {
            .target(name: "LibB", dependencies: ["LibA"]),
           ]
         )
-        """
+        """,
+      usePullDiagnostics: false
     )
 
     let (libBUri, _) = try ws.openDocument("LibB.swift")
@@ -69,21 +70,24 @@ final class DependencyTrackingTests: XCTestCase {
   }
 
   func testDependenciesUpdatedCXX() async throws {
-    let ws = try await MultiFileTestWorkspace(files: [
-      "lib.c": """
-      int libX(int value) {
-        return value ? 22 : 0;
-      }
-      """,
-      "main.c": """
-      #include "lib-generated.h"
-
-      int main(int argc, const char *argv[]) {
-        return libX(argc);
-      }
-      """,
-      "compile_flags.txt": "",
-    ])
+    let ws = try await MultiFileTestWorkspace(
+      files: [
+        "lib.c": """
+        int libX(int value) {
+          return value ? 22 : 0;
+        }
+        """,
+        "main.c": """
+        #include "lib-generated.h"
+
+        int main(int argc, const char *argv[]) {
+          return libX(argc);
+        }
+        """,
+        "compile_flags.txt": "",
+      ],
+      usePullDiagnostics: false
+    )
 
     let generatedHeaderURL = try ws.uri(for: "main.c").fileURL!.deletingLastPathComponent()
       .appendingPathComponent("lib-generated.h", isDirectory: false)

Tests/SourceKitLSPTests/LocalClangTests.swift

@@ -160,7 +160,7 @@ final class LocalClangTests: XCTestCase {
   }
 
   func testCodeAction() async throws {
-    let testClient = try await TestSourceKitLSPClient()
+    let testClient = try await TestSourceKitLSPClient(usePullDiagnostics: false)
     let uri = DocumentURI.for(.cpp)
     let positions = testClient.openDocument(
       """
@@ -220,16 +220,19 @@ final class LocalClangTests: XCTestCase {
     // Note: tests generally should avoid including system headers
     // to keep them fast and portable. This test is specifically
     // ensuring clangd can find libc++ and builtin headers.
-    let ws = try await MultiFileTestWorkspace(files: [
-      "main.cpp": """
-      #include <cstdint>
+    let ws = try await MultiFileTestWorkspace(
+      files: [
+        "main.cpp": """
+        #include <cstdint>
 
-      void test() {
-        uint64_t 1️⃣b2️⃣;
-      }
-      """,
-      "compile_flags.txt": "-Wunused-variable",
-    ])
+        void test() {
+          uint64_t 1️⃣b2️⃣;
+        }
+        """,
+        "compile_flags.txt": "-Wunused-variable",
+      ],
+      usePullDiagnostics: false
+    )
 
     let (_, positions) = try ws.openDocument("main.cpp")
 
@@ -243,41 +246,44 @@ final class LocalClangTests: XCTestCase {
   }
 
   func testClangModules() async throws {
-    let ws = try await MultiFileTestWorkspace(files: [
-      "ClangModuleA.h": """
-      #ifndef ClangModuleA_h
-      #define ClangModuleA_h
+    let ws = try await MultiFileTestWorkspace(
+      files: [
+        "ClangModuleA.h": """
+        #ifndef ClangModuleA_h
+        #define ClangModuleA_h
 
-      void func_ClangModuleA(void);
+        void func_ClangModuleA(void);
 
-      #endif
-      """,
-      "ClangModules_main.m": """
-      @import ClangModuleA;
+        #endif
+        """,
+        "ClangModules_main.m": """
+        @import ClangModuleA;
 
-      void test(void) {
-        func_ClangModuleA();
-      }
-      """,
-      "module.modulemap": """
-      module ClangModuleA {
-        header "ClangModuleA.h"
-      }
-      """,
-      "compile_flags.txt": """
-      -I
-      $TEST_DIR
-      -fmodules
-      """,
-    ])
+        void test(void) {
+          func_ClangModuleA();
+        }
+        """,
+        "module.modulemap": """
+        module ClangModuleA {
+          header "ClangModuleA.h"
+        }
+        """,
+        "compile_flags.txt": """
+        -I
+        $TEST_DIR
+        -fmodules
+        """,
+      ],
+      usePullDiagnostics: false
+    )
     _ = try ws.openDocument("ClangModules_main.m")
 
     let diags = try await ws.testClient.nextDiagnosticsNotification()
     XCTAssertEqual(diags.diagnostics.count, 0)
   }
 
   func testSemanticHighlighting() async throws {
-    let testClient = try await TestSourceKitLSPClient()
+    let testClient = try await TestSourceKitLSPClient(usePullDiagnostics: false)
     let uri = DocumentURI.for(.c)
 
     testClient.openDocument(
@@ -298,23 +304,26 @@ final class LocalClangTests: XCTestCase {
   }
 
   func testDocumentDependenciesUpdated() async throws {
-    let ws = try await MultiFileTestWorkspace(files: [
-      "Object.h": """
-      struct Object {
-        int field;
-      };
-
-      struct Object * newObject();
-      """,
-      "main.c": """
-      #include "Object.h"
-
-      int main(int argc, const char *argv[]) {
-        struct Object *obj = 1️⃣newObject();
-      }
-      """,
-      "compile_flags.txt": "",
-    ])
+    let ws = try await MultiFileTestWorkspace(
+      files: [
+        "Object.h": """
+        struct Object {
+          int field;
+        };
+
+        struct Object * newObject();
+        """,
+        "main.c": """
+        #include "Object.h"
+
+        int main(int argc, const char *argv[]) {
+          struct Object *obj = 1️⃣newObject();
+        }
+        """,
+        "compile_flags.txt": "",
+      ],
+      usePullDiagnostics: false
+    )
 
     let (mainUri, _) = try ws.openDocument("main.c")
     let headerUri = try ws.uri(for: "Object.h")