Implement more handling of client capabilities

internal/fourslash/fourslash.go

@@ -240,6 +240,7 @@ var (
 			PreselectSupport:        ptrTrue,
 			LabelDetailsSupport:     ptrTrue,
 			InsertReplaceSupport:    ptrTrue,
+			DocumentationFormat:     &[]lsproto.MarkupKind{lsproto.MarkupKindMarkdown, lsproto.MarkupKindPlainText},
 		},
 		CompletionList: &lsproto.CompletionListCapabilities{
 			ItemDefaults: &[]string{"commitCharacters", "editRange"},
@@ -251,6 +252,9 @@ var (
 	defaultTypeDefinitionCapabilities = &lsproto.TypeDefinitionClientCapabilities{
 		LinkSupport: ptrTrue,
 	}
+	defaultHoverCapabilities = &lsproto.HoverClientCapabilities{
+		ContentFormat: &[]lsproto.MarkupKind{lsproto.MarkupKindMarkdown, lsproto.MarkupKindPlainText},
+	}
 )
 
 func getCapabilitiesWithDefaults(capabilities *lsproto.ClientCapabilities) *lsproto.ClientCapabilities {
@@ -290,6 +294,9 @@ func getCapabilitiesWithDefaults(capabilities *lsproto.ClientCapabilities) *lspr
 	if capabilitiesWithDefaults.TextDocument.TypeDefinition == nil {
 		capabilitiesWithDefaults.TextDocument.TypeDefinition = defaultTypeDefinitionCapabilities
 	}
+	if capabilitiesWithDefaults.TextDocument.Hover == nil {
+		capabilitiesWithDefaults.TextDocument.Hover = defaultHoverCapabilities
+	}
 	return &capabilitiesWithDefaults
 }
 

internal/ls/completions.go

@@ -5033,6 +5033,19 @@ func GetCompletionItemData(item *lsproto.CompletionItem) (*CompletionItemData, e
 	return &itemData, nil
 }
 
+func getCompletionDocumentationFormat(clientOptions *lsproto.CompletionClientCapabilities) lsproto.MarkupKind {
+	if clientOptions == nil || clientOptions.CompletionItem == nil || clientOptions.CompletionItem.DocumentationFormat == nil {
+		// Default to plaintext if no preference specified
+		return lsproto.MarkupKindPlainText
+	}
+	formats := *clientOptions.CompletionItem.DocumentationFormat
+	if len(formats) == 0 {
+		return lsproto.MarkupKindPlainText
+	}
+	// Return the first (most preferred) format
+	return formats[0]
+}
+
 func (l *LanguageService) getCompletionItemDetails(
 	ctx context.Context,
 	program *compiler.Program,
@@ -5044,6 +5057,7 @@ func (l *LanguageService) getCompletionItemDetails(
 ) *lsproto.CompletionItem {
 	checker, done := program.GetTypeCheckerForFile(ctx, file)
 	defer done()
+	docFormat := getCompletionDocumentationFormat(clientOptions)
 	contextToken, previousToken := getRelevantTokens(position, file)
 	if IsInString(file, position, previousToken) {
 		return l.getStringLiteralCompletionDetails(
@@ -5054,6 +5068,7 @@ func (l *LanguageService) getCompletionItemDetails(
 			file,
 			position,
 			contextToken,
+			docFormat,
 		)
 	}
 
@@ -5073,16 +5088,16 @@ func (l *LanguageService) getCompletionItemDetails(
 		request := *symbolCompletion.request
 		switch request := request.(type) {
 		case *completionDataJSDocTagName:
-			return createSimpleDetails(item, itemData.Name)
+			return createSimpleDetails(item, itemData.Name, docFormat)
 		case *completionDataJSDocTag:
-			return createSimpleDetails(item, itemData.Name)
+			return createSimpleDetails(item, itemData.Name, docFormat)
 		case *completionDataJSDocParameterName:
-			return createSimpleDetails(item, itemData.Name)
+			return createSimpleDetails(item, itemData.Name, docFormat)
 		case *completionDataKeyword:
 			if core.Some(request.keywordCompletions, func(c *lsproto.CompletionItem) bool {
 				return c.Label == itemData.Name
 			}) {
-				return createSimpleDetails(item, itemData.Name)
+				return createSimpleDetails(item, itemData.Name, docFormat)
 			}
 			return item
 		default:
@@ -5097,10 +5112,11 @@ func (l *LanguageService) getCompletionItemDetails(
 			checker,
 			symbolDetails.location,
 			actions,
+			docFormat,
 		)
 	case symbolCompletion.literal != nil:
 		literal := symbolCompletion.literal
-		return createSimpleDetails(item, completionNameForLiteral(file, preferences, *literal))
+		return createSimpleDetails(item, completionNameForLiteral(file, preferences, *literal), docFormat)
 	case symbolCompletion.cases != nil:
 		// !!! exhaustive case completions
 		return item
@@ -5109,7 +5125,7 @@ func (l *LanguageService) getCompletionItemDetails(
 		if core.Some(allKeywordCompletions(), func(c *lsproto.CompletionItem) bool {
 			return c.Label == itemData.Name
 		}) {
-			return createSimpleDetails(item, itemData.Name)
+			return createSimpleDetails(item, itemData.Name, docFormat)
 		}
 		return item
 	}
@@ -5256,14 +5272,16 @@ func (l *LanguageService) getAutoImportSymbolFromCompletionEntryData(ch *checker
 func createSimpleDetails(
 	item *lsproto.CompletionItem,
 	name string,
+	docFormat lsproto.MarkupKind,
 ) *lsproto.CompletionItem {
-	return createCompletionDetails(item, name, "" /*documentation*/)
+	return createCompletionDetails(item, name, "" /*documentation*/, docFormat)
 }
 
 func createCompletionDetails(
 	item *lsproto.CompletionItem,
 	detail string,
 	documentation string,
+	docFormat lsproto.MarkupKind,
 ) *lsproto.CompletionItem {
 	// !!! fill in additionalTextEdits from code actions
 	if item.Detail == nil && detail != "" {
@@ -5272,7 +5290,7 @@ func createCompletionDetails(
 	if documentation != "" {
 		item.Documentation = &lsproto.StringOrMarkupContent{
 			MarkupContent: &lsproto.MarkupContent{
-				Kind:  lsproto.MarkupKindMarkdown,
+				Kind:  docFormat,
 				Value: documentation,
 			},
 		}
@@ -5293,19 +5311,20 @@ func (l *LanguageService) createCompletionDetailsForSymbol(
 	checker *checker.Checker,
 	location *ast.Node,
 	actions []codeAction,
+	docFormat lsproto.MarkupKind,
 ) *lsproto.CompletionItem {
 	details := make([]string, 0, len(actions)+1)
 	edits := make([]*lsproto.TextEdit, 0, len(actions))
 	for _, action := range actions {
 		details = append(details, action.description)
 		edits = append(edits, action.changes...)
 	}
-	quickInfo, documentation := l.getQuickInfoAndDocumentationForSymbol(checker, symbol, location)
+	quickInfo, documentation := l.getQuickInfoAndDocumentationForSymbol(checker, symbol, location, docFormat)
 	details = append(details, quickInfo)
 	if len(edits) != 0 {
 		item.AdditionalTextEdits = &edits
 	}
-	return createCompletionDetails(item, strings.Join(details, "\n\n"), documentation)
+	return createCompletionDetails(item, strings.Join(details, "\n\n"), documentation, docFormat)
 }
 
 // !!! snippets

internal/ls/findallreferences.go

@@ -430,7 +430,7 @@ func (l *LanguageService) ProvideReferences(ctx context.Context, params *lsproto
 	return lsproto.LocationsOrNull{Locations: &locations}, nil
 }
 
-func (l *LanguageService) ProvideImplementations(ctx context.Context, params *lsproto.ImplementationParams) (lsproto.ImplementationResponse, error) {
+func (l *LanguageService) ProvideImplementations(ctx context.Context, params *lsproto.ImplementationParams, clientSupportsLink bool) (lsproto.ImplementationResponse, error) {
 	program, sourceFile := l.getProgramAndFile(params.TextDocument.Uri)
 	position := int(l.converters.LineAndCharacterToPosition(sourceFile, params.Position))
 	node := astnav.GetTouchingPropertyName(sourceFile, position)
@@ -452,6 +452,10 @@ func (l *LanguageService) ProvideImplementations(ctx context.Context, params *ls
 		}
 	}
 
+	if clientSupportsLink {
+		links := l.convertEntriesToLocationLinks(entries)
+		return lsproto.LocationOrLocationsOrDefinitionLinksOrNull{DefinitionLinks: &links}, nil
+	}
 	locations := l.convertEntriesToLocations(entries)
 	return lsproto.LocationOrLocationsOrDefinitionLinksOrNull{Locations: &locations}, nil
 }
@@ -554,6 +558,44 @@ func (l *LanguageService) convertEntriesToLocations(entries []*ReferenceEntry) [
 	return locations
 }
 
+func (l *LanguageService) convertEntriesToLocationLinks(entries []*ReferenceEntry) []*lsproto.LocationLink {
+	links := make([]*lsproto.LocationLink, len(entries))
+	for i, entry := range entries {
+		var targetSelectionRange, targetRange *lsproto.Range
+
+		// For entries with nodes, compute ranges directly from the node
+		if entry.node != nil {
+			sourceFile := ast.GetSourceFileOfNode(entry.node)
+			entry.fileName = sourceFile.FileName()
+
+			// Get the selection range (the actual reference)
+			selectionTextRange := getRangeOfNode(entry.node, sourceFile, nil /*endNode*/)
+			targetSelectionRange = l.createLspRangeFromRange(selectionTextRange, sourceFile)
+
+			// Get the context range (broader scope including declaration context)
+			contextNode := core.OrElse(getContextNode(entry.node), entry.node)
+			contextTextRange := toContextRange(&selectionTextRange, sourceFile, contextNode)
+			if contextTextRange != nil {
+				targetRange = l.createLspRangeFromRange(*contextTextRange, sourceFile)
+			} else {
+				targetRange = targetSelectionRange
+			}
+		} else {
+			// For range entries, use the pre-computed range
+			l.resolveEntry(entry)
+			targetSelectionRange = entry.textRange
+			targetRange = targetSelectionRange
+		}
+
+		links[i] = &lsproto.LocationLink{
+			TargetUri:            lsconv.FileNameToDocumentURI(entry.fileName),
+			TargetRange:          *targetRange,
+			TargetSelectionRange: *targetSelectionRange,
+		}
+	}
+	return links
+}
+
 func (l *LanguageService) mergeReferences(program *compiler.Program, referencesToMerge ...[]*SymbolAndEntries) []*SymbolAndEntries {
 	result := []*SymbolAndEntries{}
 	getSourceFileIndexOfEntry := func(program *compiler.Program, entry *ReferenceEntry) int {

internal/ls/hover.go

@@ -18,7 +18,7 @@ const (
 	typeFormatFlags   = checker.TypeFormatFlagsUseAliasDefinedOutsideCurrentScope
 )
 
-func (l *LanguageService) ProvideHover(ctx context.Context, documentURI lsproto.DocumentUri, position lsproto.Position) (lsproto.HoverResponse, error) {
+func (l *LanguageService) ProvideHover(ctx context.Context, documentURI lsproto.DocumentUri, position lsproto.Position, contentFormat lsproto.MarkupKind) (lsproto.HoverResponse, error) {
 	program, file := l.getProgramAndFile(documentURI)
 	node := astnav.GetTouchingPropertyName(file, int(l.converters.LineAndCharacterToPosition(file, position)))
 	if node.Kind == ast.KindSourceFile {
@@ -28,43 +28,57 @@ func (l *LanguageService) ProvideHover(ctx context.Context, documentURI lsproto.
 	c, done := program.GetTypeCheckerForFile(ctx, file)
 	defer done()
 	rangeNode := getNodeForQuickInfo(node)
-	quickInfo, documentation := l.getQuickInfoAndDocumentationForSymbol(c, c.GetSymbolAtLocation(node), rangeNode)
+	quickInfo, documentation := l.getQuickInfoAndDocumentationForSymbol(c, c.GetSymbolAtLocation(node), rangeNode, contentFormat)
 	if quickInfo == "" {
 		return lsproto.HoverOrNull{}, nil
 	}
 	hoverRange := l.getLspRangeOfNode(rangeNode, nil, nil)
 
+	var content string
+	if contentFormat == lsproto.MarkupKindMarkdown {
+		content = formatQuickInfo(quickInfo) + documentation
+	} else {
+		content = quickInfo + documentation
+	}
+
 	return lsproto.HoverOrNull{
 		Hover: &lsproto.Hover{
 			Contents: lsproto.MarkupContentOrStringOrMarkedStringWithLanguageOrMarkedStrings{
 				MarkupContent: &lsproto.MarkupContent{
-					Kind:  lsproto.MarkupKindMarkdown,
-					Value: formatQuickInfo(quickInfo) + documentation,
+					Kind:  contentFormat,
+					Value: content,
 				},
 			},
 			Range: hoverRange,
 		},
 	}, nil
 }
 
-func (l *LanguageService) getQuickInfoAndDocumentationForSymbol(c *checker.Checker, symbol *ast.Symbol, node *ast.Node) (string, string) {
+func (l *LanguageService) getQuickInfoAndDocumentationForSymbol(c *checker.Checker, symbol *ast.Symbol, node *ast.Node, contentFormat lsproto.MarkupKind) (string, string) {
 	quickInfo, declaration := getQuickInfoAndDeclarationAtLocation(c, symbol, node)
 	if quickInfo == "" {
 		return "", ""
 	}
+	isMarkdown := contentFormat == lsproto.MarkupKindMarkdown
 	var b strings.Builder
 	if declaration != nil {
 		if jsdoc := getJSDocOrTag(declaration); jsdoc != nil && !containsTypedefTag(jsdoc) {
-			l.writeComments(&b, c, jsdoc.Comments())
+			l.writeComments(&b, c, jsdoc.Comments(), isMarkdown)
 			if jsdoc.Kind == ast.KindJSDoc {
 				if tags := jsdoc.AsJSDoc().Tags; tags != nil {
 					for _, tag := range tags.Nodes {
 						if tag.Kind == ast.KindJSDocTypeTag {
 							continue
 						}
-						b.WriteString("\n\n*@")
-						b.WriteString(tag.TagName().Text())
-						b.WriteString("*")
+						b.WriteString("\n\n")
+						if isMarkdown {
+							b.WriteString("*@")
+							b.WriteString(tag.TagName().Text())
+							b.WriteString("*")
+						} else {
+							b.WriteString("@")
+							b.WriteString(tag.TagName().Text())
+						}
 						switch tag.Kind {
 						case ast.KindJSDocParameterTag, ast.KindJSDocPropertyTag:
 							writeOptionalEntityName(&b, tag.Name())
@@ -90,7 +104,7 @@ func (l *LanguageService) getQuickInfoAndDocumentationForSymbol(c *checker.Check
 									b.WriteString("— ")
 								}
 							}
-							l.writeComments(&b, c, comments)
+							l.writeComments(&b, c, comments, isMarkdown)
 						}
 					}
 				}
@@ -425,24 +439,24 @@ func writeCode(b *strings.Builder, lang string, code string) {
 	b.WriteByte('\n')
 }
 
-func (l *LanguageService) writeComments(b *strings.Builder, c *checker.Checker, comments []*ast.Node) {
+func (l *LanguageService) writeComments(b *strings.Builder, c *checker.Checker, comments []*ast.Node, isMarkdown bool) {
 	for _, comment := range comments {
 		switch comment.Kind {
 		case ast.KindJSDocText:
 			b.WriteString(comment.Text())
 		case ast.KindJSDocLink, ast.KindJSDocLinkPlain:
-			l.writeJSDocLink(b, c, comment, false /*quote*/)
+			l.writeJSDocLink(b, c, comment, false /*quote*/, isMarkdown)
 		case ast.KindJSDocLinkCode:
-			l.writeJSDocLink(b, c, comment, true /*quote*/)
+			l.writeJSDocLink(b, c, comment, true /*quote*/, isMarkdown)
 		}
 	}
 }
 
-func (l *LanguageService) writeJSDocLink(b *strings.Builder, c *checker.Checker, link *ast.Node, quote bool) {
+func (l *LanguageService) writeJSDocLink(b *strings.Builder, c *checker.Checker, link *ast.Node, quote bool, isMarkdown bool) {
 	name := link.Name()
 	text := strings.Trim(link.Text(), " ")
 	if name == nil {
-		writeQuotedString(b, text, quote)
+		writeQuotedString(b, text, quote && isMarkdown)
 		return
 	}
 	if ast.IsIdentifier(name) && (name.Text() == "http" || name.Text() == "https") && strings.HasPrefix(text, "://") {
@@ -455,7 +469,16 @@ func (l *LanguageService) writeJSDocLink(b *strings.Builder, c *checker.Checker,
 				linkText = linkUri
 			}
 		}
-		writeMarkdownLink(b, linkText, linkUri, quote)
+		if isMarkdown {
+			writeMarkdownLink(b, linkText, linkUri, quote)
+		} else {
+			writeQuotedString(b, linkText, false)
+			if linkText != linkUri {
+				b.WriteString(" (")
+				b.WriteString(linkUri)
+				b.WriteString(")")
+			}
+		}
 		return
 	}
 	declarations := getDeclarationsFromLocation(c, name)
@@ -469,11 +492,15 @@ func (l *LanguageService) writeJSDocLink(b *strings.Builder, c *checker.Checker,
 		if linkText == "" {
 			linkText = getEntityNameString(name) + text[:prefixLen]
 		}
-		linkUri := fmt.Sprintf("%s#%d,%d-%d,%d", loc.Uri, loc.Range.Start.Line+1, loc.Range.Start.Character+1, loc.Range.End.Line+1, loc.Range.End.Character+1)
-		writeMarkdownLink(b, linkText, linkUri, quote)
+		if isMarkdown {
+			linkUri := fmt.Sprintf("%s#%d,%d-%d,%d", loc.Uri, loc.Range.Start.Line+1, loc.Range.Start.Character+1, loc.Range.End.Line+1, loc.Range.End.Character+1)
+			writeMarkdownLink(b, linkText, linkUri, quote)
+		} else {
+			writeQuotedString(b, linkText, false)
+		}
 		return
 	}
-	writeQuotedString(b, getEntityNameString(name)+" "+text, quote)
+	writeQuotedString(b, getEntityNameString(name)+" "+text, quote && isMarkdown)
 }
 
 func trimCommentPrefix(text string) string {