Generate LSP response types, redo nullable, delete aliases, statically type LSP handlers

internal/fourslash/baselineutil.go

@@ -49,11 +49,11 @@ type baselineFourslashLocationsOptions struct {
 	additionalSpan                *lsproto.Location
 }
 
-func (f *FourslashTest) getBaselineForLocationsWithFileContents(spans []*lsproto.Location, options baselineFourslashLocationsOptions) string {
-	return f.getBaselineForGroupedLocationsWithFileContents(collections.GroupBy(spans, func(span *lsproto.Location) lsproto.DocumentUri { return span.Uri }), options)
+func (f *FourslashTest) getBaselineForLocationsWithFileContents(spans []lsproto.Location, options baselineFourslashLocationsOptions) string {
+	return f.getBaselineForGroupedLocationsWithFileContents(collections.GroupBy(spans, func(span lsproto.Location) lsproto.DocumentUri { return span.Uri }), options)
 }
 
-func (f *FourslashTest) getBaselineForGroupedLocationsWithFileContents(groupedLocations *collections.MultiMap[lsproto.DocumentUri, *lsproto.Location], options baselineFourslashLocationsOptions) string {
+func (f *FourslashTest) getBaselineForGroupedLocationsWithFileContents(groupedLocations *collections.MultiMap[lsproto.DocumentUri, lsproto.Location], options baselineFourslashLocationsOptions) string {
 	// We must always print the file containing the marker,
 	// but don't want to print it twice at the end if it already
 	// found in a file with ranges.
@@ -85,9 +85,9 @@ func (f *FourslashTest) getBaselineForGroupedLocationsWithFileContents(groupedLo
 			foundMarker = true
 		}
 
-		documentSpans := core.Map(locations, func(location *lsproto.Location) *documentSpan {
+		documentSpans := core.Map(locations, func(location lsproto.Location) *documentSpan {
 			return &documentSpan{
-				Location: *location,
+				Location: location,
 			}
 		})
 		baselineEntries = append(baselineEntries, f.getBaselineContentForFile(path, content, documentSpans, nil, options))

internal/fourslash/fourslash.go

@@ -230,8 +230,8 @@ func (f *FourslashTest) initialize(t *testing.T, capabilities *lsproto.ClientCap
 	params := &lsproto.InitializeParams{}
 	params.Capabilities = getCapabilitiesWithDefaults(capabilities)
 	// !!! check for errors?
-	f.sendRequest(t, lsproto.MethodInitialize, params)
-	f.sendNotification(t, lsproto.MethodInitialized, &lsproto.InitializedParams{})
+	sendRequest(t, f, lsproto.InitializeInfo, params)
+	sendNotification(t, f, lsproto.InitializedInfo, &lsproto.InitializedParams{})
 }
 
 var (
@@ -267,20 +267,25 @@ func getCapabilitiesWithDefaults(capabilities *lsproto.ClientCapabilities) *lspr
 	return &capabilitiesWithDefaults
 }
 
-func (f *FourslashTest) sendRequest(t *testing.T, method lsproto.Method, params any) *lsproto.Message {
+func sendRequest[Params, Resp any](t *testing.T, f *FourslashTest, info lsproto.RequestInfo[Params, Resp], params Params) (*lsproto.Message, Resp, bool) {
 	id := f.nextID()
 	req := lsproto.NewRequestMessage(
-		method,
+		info.Method,
 		lsproto.NewID(lsproto.IntegerOrString{Integer: &id}),
 		params,
 	)
 	f.writeMsg(t, req.Message())
-	return f.readMsg(t)
+	resp := f.readMsg(t)
+	if resp == nil {
+		return nil, *new(Resp), false
+	}
+	result, ok := resp.AsResponse().Result.(Resp)
+	return resp, result, ok
 }
 
-func (f *FourslashTest) sendNotification(t *testing.T, method lsproto.Method, params any) {
+func sendNotification[Params any](t *testing.T, f *FourslashTest, info lsproto.NotificationInfo[Params], params Params) {
 	notification := lsproto.NewNotificationMessage(
-		method,
+		info.Method,
 		params,
 	)
 	f.writeMsg(t, notification.Message())
@@ -430,7 +435,7 @@ func (f *FourslashTest) openFile(t *testing.T, filename string) {
 		t.Fatalf("File %s not found in test data", filename)
 	}
 	f.activeFilename = filename
-	f.sendNotification(t, lsproto.MethodTextDocumentDidOpen, &lsproto.DidOpenTextDocumentParams{
+	sendNotification(t, f, lsproto.TextDocumentDidOpenInfo, &lsproto.DidOpenTextDocumentParams{
 		TextDocument: &lsproto.TextDocumentItem{
 			Uri:        ls.FileNameToDocumentURI(filename),
 			LanguageId: getLanguageKind(filename),
@@ -544,17 +549,14 @@ func (f *FourslashTest) verifyCompletionsWorker(t *testing.T, expected *Completi
 		TextDocumentPositionParams: f.currentTextDocumentPositionParams(),
 		Context:                    &lsproto.CompletionContext{},
 	}
-	resMsg := f.sendRequest(t, lsproto.MethodTextDocumentCompletion, params)
+	resMsg, result, resultOk := sendRequest(t, f, lsproto.TextDocumentCompletionInfo, params)
 	if resMsg == nil {
 		t.Fatalf(prefix+"Nil response received for completion request", f.lastKnownMarkerName)
 	}
-	result := resMsg.AsResponse().Result
-	switch result := result.(type) {
-	case *lsproto.CompletionList:
-		f.verifyCompletionsResult(t, f.currentCaretPosition, result, expected, prefix)
-	default:
-		t.Fatalf(prefix+"Unexpected response type for completion request: %v", result)
+	if !resultOk {
+		t.Fatalf(prefix+"Unexpected response type for completion request: %T", resMsg.AsResponse().Result)
 	}
+	f.verifyCompletionsResult(t, f.currentCaretPosition, result.List, expected, prefix)
 }
 
 func (f *FourslashTest) verifyCompletionsResult(
@@ -732,15 +734,14 @@ var completionIgnoreOpts = cmp.FilterPath(
 
 func (f *FourslashTest) verifyCompletionItem(t *testing.T, prefix string, actual *lsproto.CompletionItem, expected *lsproto.CompletionItem) {
 	if expected.Detail != nil || expected.Documentation != nil {
-		response := f.sendRequest(t, lsproto.MethodCompletionItemResolve, actual)
-		if response == nil {
+		resMsg, result, resultOk := sendRequest(t, f, lsproto.CompletionItemResolveInfo, actual)
+		if resMsg == nil {
 			t.Fatal(prefix + "Expected non-nil response for completion item resolve, got nil")
 		}
-		resolvedItem, ok := response.AsResponse().Result.(*lsproto.CompletionItem)
-		if !ok {
-			t.Fatalf(prefix+"Expected response to be *lsproto.CompletionItem, got %T", response.AsResponse().Result)
+		if !resultOk {
+			t.Fatalf(prefix+"Unexpected response type for completion item resolve: %T", resMsg.AsResponse().Result)
 		}
-		actual = resolvedItem
+		actual = result
 	}
 	assertDeepEqual(t, actual, expected, prefix, completionIgnoreOpts)
 	if expected.Kind != nil {
@@ -799,28 +800,27 @@ func (f *FourslashTest) VerifyBaselineFindAllReferences(
 			TextDocumentPositionParams: f.currentTextDocumentPositionParams(),
 			Context:                    &lsproto.ReferenceContext{},
 		}
-		resMsg := f.sendRequest(t, lsproto.MethodTextDocumentReferences, params)
+		resMsg, result, resultOk := sendRequest(t, f, lsproto.TextDocumentReferencesInfo, params)
 		if resMsg == nil {
 			if f.lastKnownMarkerName == nil {
 				t.Fatalf("Nil response received for references request at pos %v", f.currentCaretPosition)
 			} else {
 				t.Fatalf("Nil response received for references request at marker '%s'", *f.lastKnownMarkerName)
 			}
 		}
-
-		result := resMsg.AsResponse().Result
-		if resultAsLocation, ok := result.([]*lsproto.Location); ok {
-			f.baseline.addResult("findAllReferences", f.getBaselineForLocationsWithFileContents(resultAsLocation, baselineFourslashLocationsOptions{
-				marker:     markerOrRange.GetMarker(),
-				markerName: "/*FIND ALL REFS*/",
-			}))
-		} else {
+		if !resultOk {
 			if f.lastKnownMarkerName == nil {
-				t.Fatalf("Unexpected references response type at pos %v: %T", f.currentCaretPosition, result)
+				t.Fatalf("Unexpected references response type at pos %v: %T", f.currentCaretPosition, resMsg.AsResponse().Result)
 			} else {
-				t.Fatalf("Unexpected references response type at marker '%s': %T", *f.lastKnownMarkerName, result)
+				t.Fatalf("Unexpected references response type at marker '%s': %T", *f.lastKnownMarkerName, resMsg.AsResponse().Result)
 			}
 		}
+
+		f.baseline.addResult("findAllReferences", f.getBaselineForLocationsWithFileContents(*result, baselineFourslashLocationsOptions{
+			marker:     markerOrRange.GetMarker(),
+			markerName: "/*FIND ALL REFS*/",
+		}))
+
 	}
 
 	baseline.Run(t, f.baseline.getBaselineFileName(), f.baseline.content.String(), baseline.Options{})
@@ -854,39 +854,38 @@ func (f *FourslashTest) VerifyBaselineGoToDefinition(
 		params := &lsproto.DefinitionParams{
 			TextDocumentPositionParams: f.currentTextDocumentPositionParams(),
 		}
-		resMsg := f.sendRequest(t, lsproto.MethodTextDocumentDefinition, params)
+
+		resMsg, result, resultOk := sendRequest(t, f, lsproto.TextDocumentDefinitionInfo, params)
 		if resMsg == nil {
 			if f.lastKnownMarkerName == nil {
 				t.Fatalf("Nil response received for definition request at pos %v", f.currentCaretPosition)
 			} else {
 				t.Fatalf("Nil response received for definition request at marker '%s'", *f.lastKnownMarkerName)
 			}
 		}
-
-		result := resMsg.AsResponse().Result
-		if resultAsLocOrLocations, ok := result.(*lsproto.LocationOrLocations); ok {
-			var resultAsLocations []*lsproto.Location
-			if resultAsLocOrLocations != nil {
-				if resultAsLocOrLocations.Locations != nil {
-					resultAsLocations = core.Map(*resultAsLocOrLocations.Locations, func(loc lsproto.Location) *lsproto.Location {
-						return &loc
-					})
-				} else {
-					resultAsLocations = []*lsproto.Location{resultAsLocOrLocations.Location}
-				}
+		if !resultOk {
+			if f.lastKnownMarkerName == nil {
+				t.Fatalf("Unexpected definition response type at pos %v: %T", f.currentCaretPosition, resMsg.AsResponse().Result)
+			} else {
+				t.Fatalf("Unexpected definition response type at marker '%s': %T", *f.lastKnownMarkerName, resMsg.AsResponse().Result)
 			}
+		}
 
-			f.baseline.addResult("goToDefinition", f.getBaselineForLocationsWithFileContents(resultAsLocations, baselineFourslashLocationsOptions{
-				marker:     markerOrRange.GetMarker(),
-				markerName: "/*GO TO DEFINITION*/",
-			}))
-		} else {
-			if f.lastKnownMarkerName == nil {
-				t.Fatalf("Unexpected definition response type at pos %v: %T", f.currentCaretPosition, result)
+		var resultAsLocations []lsproto.Location
+		if result != nil {
+			if result.Locations != nil {
+				resultAsLocations = *result.Locations
+			} else if result.Location != nil {
+				resultAsLocations = []lsproto.Location{*result.Location}
 			} else {
-				t.Fatalf("Unexpected definition response type at marker '%s': %T", *f.lastKnownMarkerName, result)
+				t.Fatalf("Unexpected definition response type at marker '%s': %T", *f.lastKnownMarkerName, result.DefinitionLinks)
 			}
 		}
+
+		f.baseline.addResult("goToDefinition", f.getBaselineForLocationsWithFileContents(resultAsLocations, baselineFourslashLocationsOptions{
+			marker:     markerOrRange.GetMarker(),
+			markerName: "/*GO TO DEFINITION*/",
+		}))
 	}
 
 	baseline.Run(t, f.baseline.getBaselineFileName(), f.baseline.content.String(), baseline.Options{})
@@ -1060,16 +1059,16 @@ func (f *FourslashTest) editScript(t *testing.T, fileName string, start int, end
 	if err != nil {
 		panic(fmt.Sprintf("Failed to write file %s: %v", fileName, err))
 	}
-	f.sendNotification(t, lsproto.MethodTextDocumentDidChange, &lsproto.DidChangeTextDocumentParams{
+	sendNotification(t, f, lsproto.TextDocumentDidChangeInfo, &lsproto.DidChangeTextDocumentParams{
 		TextDocument: lsproto.VersionedTextDocumentIdentifier{
 			TextDocumentIdentifier: lsproto.TextDocumentIdentifier{
 				Uri: ls.FileNameToDocumentURI(fileName),
 			},
 			Version: script.version,
 		},
-		ContentChanges: []lsproto.TextDocumentContentChangeEvent{
+		ContentChanges: []lsproto.TextDocumentContentChangePartialOrWholeDocument{
 			{
-				TextDocumentContentChangePartial: &lsproto.TextDocumentContentChangePartial{
+				Partial: &lsproto.TextDocumentContentChangePartial{
 					Range: changeRange,
 					Text:  newText,
 				},

internal/ls/definition.go

@@ -11,7 +11,7 @@ import (
 	"github.com/microsoft/typescript-go/internal/scanner"
 )
 
-func (l *LanguageService) ProvideDefinition(ctx context.Context, documentURI lsproto.DocumentUri, position lsproto.Position) (*lsproto.Definition, error) {
+func (l *LanguageService) ProvideDefinition(ctx context.Context, documentURI lsproto.DocumentUri, position lsproto.Position) (lsproto.DefinitionResponse, error) {
 	program, file := l.getProgramAndFile(documentURI)
 	node := astnav.GetTouchingPropertyName(file, int(l.converters.LineAndCharacterToPosition(file, position)))
 	if node.Kind == ast.KindSourceFile {
@@ -84,7 +84,7 @@ func (l *LanguageService) ProvideDefinition(ctx context.Context, documentURI lsp
 	return nil, nil
 }
 
-func (l *LanguageService) ProvideTypeDefinition(ctx context.Context, documentURI lsproto.DocumentUri, position lsproto.Position) (*lsproto.Definition, error) {
+func (l *LanguageService) ProvideTypeDefinition(ctx context.Context, documentURI lsproto.DocumentUri, position lsproto.Position) (lsproto.DefinitionResponse, error) {
 	program, file := l.getProgramAndFile(documentURI)
 	node := astnav.GetTouchingPropertyName(file, int(l.converters.LineAndCharacterToPosition(file, position)))
 	if node.Kind == ast.KindSourceFile {
@@ -126,7 +126,7 @@ func getDeclarationNameForKeyword(node *ast.Node) *ast.Node {
 	return node
 }
 
-func (l *LanguageService) createLocationsFromDeclarations(declarations []*ast.Node) *lsproto.Definition {
+func (l *LanguageService) createLocationsFromDeclarations(declarations []*ast.Node) lsproto.DefinitionResponse {
 	someHaveBody := core.Some(declarations, func(node *ast.Node) bool { return node.Body() != nil })
 	locations := make([]lsproto.Location, 0, len(declarations))
 	for _, decl := range declarations {
@@ -139,11 +139,11 @@ func (l *LanguageService) createLocationsFromDeclarations(declarations []*ast.No
 			})
 		}
 	}
-	return &lsproto.Definition{Locations: &locations}
+	return &lsproto.LocationOrLocationsOrDefinitionLinks{Locations: &locations}
 }
 
-func (l *LanguageService) createLocationFromFileAndRange(file *ast.SourceFile, textRange core.TextRange) *lsproto.Definition {
-	return &lsproto.Definition{
+func (l *LanguageService) createLocationFromFileAndRange(file *ast.SourceFile, textRange core.TextRange) lsproto.DefinitionResponse {
+	return &lsproto.LocationOrLocationsOrDefinitionLinks{
 		Location: &lsproto.Location{
 			Uri:   FileNameToDocumentURI(file.FileName()),
 			Range: *l.createLspRangeFromBounds(textRange.Pos(), textRange.End(), file),

internal/ls/definition_test.go

@@ -22,15 +22,15 @@ func TestDefinition(t *testing.T) {
 	testCases := []struct {
 		title    string
 		input    string
-		expected map[string]lsproto.Definition
+		expected map[string]lsproto.DefinitionResponse
 	}{
 		{
 			title: "localFunction",
 			input: `
 // @filename: index.ts
 function localFunction() { }
 /*localFunction*/localFunction();`,
-			expected: map[string]lsproto.Definition{
+			expected: map[string]lsproto.DefinitionResponse{
 				"localFunction": {
 					Locations: &[]lsproto.Location{{
 						Uri:   ls.FileNameToDocumentURI("/index.ts"),
@@ -49,7 +49,7 @@ function localFunction() { }
 	}
 }
 
-func runDefinitionTest(t *testing.T, input string, expected map[string]lsproto.Definition) {
+func runDefinitionTest(t *testing.T, input string, expected map[string]lsproto.DefinitionResponse) {
 	testData := fourslash.ParseTestData(t, input, "/mainFile.ts")
 	file := testData.Files[0].FileName()
 	markerPositions := testData.MarkerPositions
@@ -69,6 +69,6 @@ func runDefinitionTest(t *testing.T, input string, expected map[string]lsproto.D
 			ls.FileNameToDocumentURI(file),
 			marker.LSPosition)
 		assert.NilError(t, err)
-		assert.DeepEqual(t, *locations, expectedResult)
+		assert.DeepEqual(t, locations, expectedResult)
 	}
 }

internal/ls/diagnostics.go

@@ -10,8 +10,8 @@ import (
 	"github.com/microsoft/typescript-go/internal/lsp/lsproto"
 )
 
-func (l *LanguageService) GetDocumentDiagnostics(ctx context.Context, documentURI lsproto.DocumentUri) (*lsproto.DocumentDiagnosticReport, error) {
-	program, file := l.getProgramAndFile(documentURI)
+func (l *LanguageService) ProvideDiagnostics(ctx context.Context, uri lsproto.DocumentUri) (lsproto.DocumentDiagnosticResponse, error) {
+	program, file := l.getProgramAndFile(uri)
 
 	diagnostics := make([][]*ast.Diagnostic, 0, 3)
 	if syntaxDiagnostics := program.GetSyntacticDiagnostics(ctx, file); len(syntaxDiagnostics) != 0 {
@@ -26,8 +26,8 @@ func (l *LanguageService) GetDocumentDiagnostics(ctx context.Context, documentUR
 		}
 	}
 
-	return &lsproto.DocumentDiagnosticReport{
-		RelatedFullDocumentDiagnosticReport: &lsproto.RelatedFullDocumentDiagnosticReport{
+	return lsproto.RelatedFullDocumentDiagnosticReportOrUnchangedDocumentDiagnosticReport{
+		FullDocumentDiagnosticReport: &lsproto.RelatedFullDocumentDiagnosticReport{
 			FullDocumentDiagnosticReport: lsproto.FullDocumentDiagnosticReport{
 				Items: toLSPDiagnostics(l.converters, diagnostics...),
 			},

internal/ls/findallreferences.go

@@ -396,7 +396,7 @@ func getSymbolScope(symbol *ast.Symbol) *ast.Node {
 
 // === functions on (*ls) ===
 
-func (l *LanguageService) ProvideReferences(params *lsproto.ReferenceParams) []*lsproto.Location {
+func (l *LanguageService) ProvideReferences(params *lsproto.ReferenceParams) []lsproto.Location {
 	// `findReferencedSymbols` except only computes the information needed to return reference locations
 	program, sourceFile := l.getProgramAndFile(params.TextDocument.Uri)
 	position := int(l.converters.LineAndCharacterToPosition(sourceFile, params.Position))
@@ -409,7 +409,7 @@ func (l *LanguageService) ProvideReferences(params *lsproto.ReferenceParams) []*
 	return core.FlatMap(symbolsAndEntries, l.convertSymbolAndEntriesToLocations)
 }
 
-func (l *LanguageService) ProvideImplementations(params *lsproto.ImplementationParams) []*lsproto.Location {
+func (l *LanguageService) ProvideImplementations(params *lsproto.ImplementationParams) []lsproto.Location {
 	program, sourceFile := l.getProgramAndFile(params.TextDocument.Uri)
 	position := int(l.converters.LineAndCharacterToPosition(sourceFile, params.Position))
 	node := astnav.GetTouchingPropertyName(sourceFile, position)
@@ -437,19 +437,19 @@ func (l *LanguageService) getImplementationReferenceEntries(program *compiler.Pr
 }
 
 // == functions for conversions ==
-func (l *LanguageService) convertSymbolAndEntriesToLocations(s *SymbolAndEntries) []*lsproto.Location {
+func (l *LanguageService) convertSymbolAndEntriesToLocations(s *SymbolAndEntries) []lsproto.Location {
 	return l.convertEntriesToLocations(s.references)
 }
 
-func (l *LanguageService) convertEntriesToLocations(entries []*referenceEntry) []*lsproto.Location {
-	locations := make([]*lsproto.Location, len(entries))
+func (l *LanguageService) convertEntriesToLocations(entries []*referenceEntry) []lsproto.Location {
+	locations := make([]lsproto.Location, len(entries))
 	for i, entry := range entries {
 		if entry.textRange == nil {
 			sourceFile := ast.GetSourceFileOfNode(entry.node)
 			entry.textRange = l.getRangeOfNode(entry.node, sourceFile, nil /*endNode*/)
 			entry.fileName = sourceFile.FileName()
 		}
-		locations[i] = &lsproto.Location{
+		locations[i] = lsproto.Location{
 			Uri:   FileNameToDocumentURI(entry.fileName),
 			Range: *entry.textRange,
 		}

internal/ls/findallreferences_test.go

@@ -36,7 +36,7 @@ func runFindReferencesTest(t *testing.T, input string, expectedLocations map[str
 		libReference := 0
 
 		for _, loc := range referencesResult {
-			if name, ok := allExpectedLocations[*loc]; ok {
+			if name, ok := allExpectedLocations[loc]; ok {
 				// check if returned ref location is in this request's expected set
 				assert.Assert(t, expectedSet.Has(name), "Reference to '%s' not expected when find all references requested at %s", name, requestMarkerName)
 			} else if strings.Contains(string(loc.Uri), "//bundled") && strings.Contains(string(loc.Uri), "//libs") {

internal/ls/findallreferencesexport_test.go

@@ -17,7 +17,7 @@ func (l *LanguageService) GetExpectedReferenceFromMarker(fileName string, pos in
 	}
 }
 
-func (l *LanguageService) TestProvideReferences(fileName string, pos int) []*lsproto.Location {
+func (l *LanguageService) TestProvideReferences(fileName string, pos int) []lsproto.Location {
 	_, sourceFile := l.tryGetProgramAndFile(fileName)
 	lsPos := l.converters.PositionToLineAndCharacter(sourceFile, core.TextPos(pos))
 	return l.ProvideReferences(&lsproto.ReferenceParams{