LSP add workspace symbol queries (#4070)

Author: emcfarlane

private/buf/buflsp/server.go

@@ -22,6 +22,7 @@ import (
 	"errors"
 	"fmt"
 	"runtime/debug"
+	"slices"
 	"strings"
 
 	"github.com/bufbuild/buf/private/buf/bufformat"
@@ -137,6 +138,7 @@ func (s *server) Initialize(
 				},
 				Full: true,
 			},
+			WorkspaceSymbolProvider: true,
 		},
 		ServerInfo: info,
 	}, nil
@@ -505,3 +507,48 @@ func (s *server) SemanticTokensFull(
 	}
 	return &protocol.SemanticTokens{Data: encoded}, nil
 }
+
+// Symbols is the entry point for workspace-wide symbol search.
+func (s *server) Symbols(
+	ctx context.Context,
+	params *protocol.WorkspaceSymbolParams,
+) ([]protocol.SymbolInformation, error) {
+	const maxResults = 1000 // Limit results to avoid overwhelming clients
+	query := strings.ToLower(params.Query)
+
+	var results []protocol.SymbolInformation
+	for uri, file := range s.fileManager.uriToFile.Range {
+		if file.ir.IsZero() {
+			s.lsp.logger.DebugContext(ctx, fmt.Sprintf("workspace symbol: skipping file without IR: %s", uri))
+			continue
+		}
+
+		// Search through all symbols in this file.
+		for _, sym := range file.symbols {
+			if sym.ir.IsZero() {
+				continue
+			}
+			symbolInfo := sym.GetSymbolInformation()
+			if symbolInfo.Name == "" {
+				continue // Symbol information not supported for this symbol.
+			}
+
+			// Filter by query (case-insensitive substring match)
+			if query != "" && !strings.Contains(strings.ToLower(symbolInfo.Name), query) {
+				continue
+			}
+			results = append(results, symbolInfo)
+			if len(results) >= maxResults {
+				break
+			}
+		}
+	}
+
+	slices.SortFunc(results, func(a, b protocol.SymbolInformation) int {
+		if a.Name != b.Name {
+			return strings.Compare(a.Name, b.Name)
+		}
+		return strings.Compare(a.ContainerName, b.ContainerName)
+	})
+	return results, nil
+}

private/buf/buflsp/symbol.go

@@ -257,6 +257,55 @@ func (s *symbol) FormatDocs(ctx context.Context) string {
 	return tooltip.String()
 }
 
+// GetSymbolInformat returns the protocol symbol information for the symbol.
+func (s *symbol) GetSymbolInformation() protocol.SymbolInformation {
+	if s.ir.IsZero() {
+		return protocol.SymbolInformation{}
+	}
+
+	fullName := s.ir.FullName()
+	name := fullName.Name()
+	if name == "" {
+		return protocol.SymbolInformation{}
+	}
+	parentFullName := fullName.Parent()
+	containerName := string(parentFullName)
+
+	location := protocol.Location{
+		URI:   s.file.uri,
+		Range: s.Range(),
+	}
+
+	// Determine the symbol kind for LSP.
+	var kind protocol.SymbolKind
+	switch s.ir.Kind() {
+	case ir.SymbolKindMessage:
+		kind = protocol.SymbolKindClass // Messages are like classes
+	case ir.SymbolKindEnum:
+		kind = protocol.SymbolKindEnum
+	case ir.SymbolKindEnumValue:
+		kind = protocol.SymbolKindEnumMember
+	case ir.SymbolKindField:
+		kind = protocol.SymbolKindField
+	case ir.SymbolKindExtension:
+		kind = protocol.SymbolKindField
+	case ir.SymbolKindOneof:
+		kind = protocol.SymbolKindClass // Oneof are like classes
+	case ir.SymbolKindService:
+		kind = protocol.SymbolKindInterface // Services are like interfaces
+	case ir.SymbolKindMethod:
+		kind = protocol.SymbolKindMethod
+	default:
+		kind = protocol.SymbolKindVariable
+	}
+	return protocol.SymbolInformation{
+		Name:          name,
+		Kind:          kind,
+		Location:      location,
+		ContainerName: containerName,
+	}
+}
+
 func protowireTypeForPredeclared(name predeclared.Name) protowire.Type {
 	switch name {
 	case predeclared.Bool, predeclared.Int32, predeclared.Int64, predeclared.UInt32,