Port source map position mapping + go to definition source mapping

internal/api/api.go

@@ -160,7 +160,7 @@ func (api *API) GetSymbolAtPosition(ctx context.Context, projectId Handle[projec
 		return nil, errors.New("project not found")
 	}
 
-	languageService := ls.NewLanguageService(project, snapshot.Converters())
+	languageService := ls.NewLanguageService(project.GetProgram(), snapshot)
 	symbol, err := languageService.GetSymbolAtPosition(ctx, fileName, position)
 	if err != nil || symbol == nil {
 		return nil, err
@@ -202,7 +202,7 @@ func (api *API) GetSymbolAtLocation(ctx context.Context, projectId Handle[projec
 	if node == nil {
 		return nil, fmt.Errorf("node of kind %s not found at position %d in file %q", kind.String(), pos, sourceFile.FileName())
 	}
-	languageService := ls.NewLanguageService(project, snapshot.Converters())
+	languageService := ls.NewLanguageService(project.GetProgram(), snapshot)
 	symbol := languageService.GetSymbolAtLocation(ctx, node)
 	if symbol == nil {
 		return nil, nil
@@ -232,7 +232,7 @@ func (api *API) GetTypeOfSymbol(ctx context.Context, projectId Handle[project.Pr
 	if !ok {
 		return nil, fmt.Errorf("symbol %q not found", symbolHandle)
 	}
-	languageService := ls.NewLanguageService(project, snapshot.Converters())
+	languageService := ls.NewLanguageService(project.GetProgram(), snapshot)
 	t := languageService.GetTypeOfSymbol(ctx, symbol)
 	if t == nil {
 		return nil, nil

internal/core/core.go

@@ -648,3 +648,22 @@ func Deduplicate[T comparable](slice []T) []T {
 	}
 	return slice
 }
+
+func DeduplicateSorted[T any](slice []T, isEqual func(a, b T) bool) []T {
+	if len(slice) == 0 {
+		return slice
+	}
+	last := slice[0]
+	deduplicated := slice[:1]
+	for i := 1; i < len(slice); i++ {
+		next := slice[i]
+		if isEqual(last, next) {
+			continue
+		}
+
+		deduplicated = append(deduplicated, next)
+		last = next
+	}
+
+	return deduplicated
+}

internal/ls/autoimports.go

@@ -702,7 +702,7 @@ func (l *LanguageService) createPackageJsonImportFilter(fromFile *ast.SourceFile
 			return nil
 		}
 		specifier := modulespecifiers.GetNodeModulesPackageName(
-			l.host.GetProgram().Options(),
+			l.program.Options(),
 			fromFile,
 			importedFileName,
 			moduleSpecifierResolutionHost,

internal/ls/definition.go

@@ -104,20 +104,17 @@ func (l *LanguageService) createLocationsFromDeclarations(declarations []*ast.No
 	for _, decl := range declarations {
 		file := ast.GetSourceFileOfNode(decl)
 		name := core.OrElse(ast.GetNameOfDeclaration(decl), decl)
-		locations = core.AppendIfUnique(locations, lsproto.Location{
-			Uri:   FileNameToDocumentURI(file.FileName()),
-			Range: *l.createLspRangeFromNode(name, file),
-		})
+		nodeRange := createRangeFromNode(name, file)
+		mappedLocation := l.getMappedLocation(file.FileName(), nodeRange)
+		locations = core.AppendIfUnique(locations, mappedLocation)
 	}
 	return lsproto.LocationOrLocationsOrDefinitionLinksOrNull{Locations: &locations}
 }
 
 func (l *LanguageService) createLocationFromFileAndRange(file *ast.SourceFile, textRange core.TextRange) lsproto.DefinitionResponse {
+	mappedLocation := l.getMappedLocation(file.FileName(), textRange)
 	return lsproto.LocationOrLocationsOrDefinitionLinksOrNull{
-		Location: &lsproto.Location{
-			Uri:   FileNameToDocumentURI(file.FileName()),
-			Range: *l.createLspRangeFromBounds(textRange.Pos(), textRange.End(), file),
-		},
+		Location: &mappedLocation,
 	}
 }
 

internal/ls/host.go

@@ -1,9 +1,8 @@
 package ls
 
-import (
-	"github.com/microsoft/typescript-go/internal/compiler"
-)
-
 type Host interface {
-	GetProgram() *compiler.Program
+	UseCaseSensitiveFileNames() bool
+	ReadFile(path string) (contents string, ok bool)
+	FileExists(path string) bool
+	Converters() *Converters
 }

internal/ls/languageservice.go

@@ -4,22 +4,30 @@ import (
 	"github.com/microsoft/typescript-go/internal/ast"
 	"github.com/microsoft/typescript-go/internal/compiler"
 	"github.com/microsoft/typescript-go/internal/lsp/lsproto"
+	"github.com/microsoft/typescript-go/internal/sourcemap"
 )
 
 type LanguageService struct {
-	host       Host
-	converters *Converters
+	host                    Host
+	program                 *compiler.Program
+	converters              *Converters
+	documentPositionMappers map[string]*sourcemap.DocumentPositionMapper
 }
 
-func NewLanguageService(host Host, converters *Converters) *LanguageService {
+func NewLanguageService(
+	program *compiler.Program,
+	host Host,
+) *LanguageService {
 	return &LanguageService{
-		host:       host,
-		converters: converters,
+		host:                    host,
+		program:                 program,
+		converters:              host.Converters(),
+		documentPositionMappers: map[string]*sourcemap.DocumentPositionMapper{},
 	}
 }
 
 func (l *LanguageService) GetProgram() *compiler.Program {
-	return l.host.GetProgram()
+	return l.program
 }
 
 func (l *LanguageService) tryGetProgramAndFile(fileName string) (*compiler.Program, *ast.SourceFile) {
@@ -36,3 +44,32 @@ func (l *LanguageService) getProgramAndFile(documentURI lsproto.DocumentUri) (*c
 	}
 	return program, file
 }
+
+func (l *LanguageService) GetDocumentPositionMapper(fileName string) *sourcemap.DocumentPositionMapper {
+	d, ok := l.documentPositionMappers[fileName]
+	if !ok {
+		d = sourcemap.GetDocumentPositionMapper(l, fileName)
+		l.documentPositionMappers[fileName] = d
+	}
+	return d
+}
+
+func (l *LanguageService) ReadFile(fileName string) (string, bool) {
+	return l.host.ReadFile(fileName)
+}
+
+func (l *LanguageService) UseCaseSensitiveFileNames() bool {
+	return l.host.UseCaseSensitiveFileNames()
+}
+
+func (l *LanguageService) GetLineInfo(fileName string) *sourcemap.LineInfo {
+	text, ok := l.ReadFile(fileName)
+	if !ok {
+		return nil
+	}
+	lineMap := l.converters.getLineMap(fileName)
+	if lineMap == nil {
+		return nil
+	}
+	return sourcemap.CreateLineInfo(text, lineMap.LineStarts)
+}

internal/ls/source_map.go

@@ -0,0 +1,81 @@
+package ls
+
+import (
+	"github.com/microsoft/typescript-go/internal/core"
+	"github.com/microsoft/typescript-go/internal/debug"
+	"github.com/microsoft/typescript-go/internal/lsp/lsproto"
+	"github.com/microsoft/typescript-go/internal/sourcemap"
+	"github.com/microsoft/typescript-go/internal/tspath"
+)
+
+func (l *LanguageService) getMappedLocation(fileName string, fileRange core.TextRange) lsproto.Location {
+	startPos := l.tryGetSourcePosition(fileName, core.TextPos(fileRange.Pos()))
+	if startPos == nil {
+		lspRange := l.createLspRangeFromRange(fileRange, l.getScript(fileName))
+		return lsproto.Location{
+			Uri:   FileNameToDocumentURI(fileName),
+			Range: *lspRange,
+		}
+	}
+	endPos := l.tryGetSourcePosition(fileName, core.TextPos(fileRange.End()))
+	debug.Assert(endPos.FileName == startPos.FileName, "start and end should be in same file")
+	newRange := core.NewTextRange(startPos.Pos, endPos.Pos)
+	lspRange := l.createLspRangeFromRange(newRange, l.getScript(startPos.FileName))
+	return lsproto.Location{
+		Uri:   FileNameToDocumentURI(startPos.FileName),
+		Range: *lspRange,
+	}
+}
+
+type script struct {
+	fileName string
+	text     string
+}
+
+func (s *script) FileName() string {
+	return s.fileName
+}
+
+func (s *script) Text() string {
+	return s.text
+}
+
+func (l *LanguageService) getScript(fileName string) *script {
+	text, ok := l.host.ReadFile(fileName)
+	if !ok {
+		return nil
+	}
+	return &script{fileName: fileName, text: text}
+}
+
+func (l *LanguageService) tryGetSourcePosition(
+	fileName string,
+	position core.TextPos,
+) *sourcemap.DocumentPosition {
+	newPos := l.tryGetSourcePositionWorker(fileName, position)
+	if newPos != nil {
+		if !l.host.FileExists(newPos.FileName) {
+			return nil
+		}
+	}
+	return newPos
+}
+
+func (l *LanguageService) tryGetSourcePositionWorker(
+	fileName string,
+	position core.TextPos,
+) *sourcemap.DocumentPosition {
+	if !tspath.IsDeclarationFileName(fileName) {
+		return nil
+	}
+
+	positionMapper := l.GetDocumentPositionMapper(fileName)
+	documentPos := positionMapper.GetSourcePosition(&sourcemap.DocumentPosition{FileName: fileName, Pos: int(position)})
+	if documentPos == nil {
+		return nil
+	}
+	if newPos := l.tryGetSourcePositionWorker(documentPos.FileName, core.TextPos(documentPos.Pos)); newPos != nil {
+		return newPos
+	}
+	return documentPos
+}

internal/ls/utilities.go

@@ -433,11 +433,20 @@ func (l *LanguageService) createLspRangeFromNode(node *ast.Node, file *ast.Sourc
 	return l.createLspRangeFromBounds(scanner.GetTokenPosOfNode(node, file, false /*includeJSDoc*/), node.End(), file)
 }
 
+func createRangeFromNode(node *ast.Node, file *ast.SourceFile) core.TextRange {
+	return core.NewTextRange(scanner.GetTokenPosOfNode(node, file, false /*includeJSDoc*/), node.End())
+}
+
 func (l *LanguageService) createLspRangeFromBounds(start, end int, file *ast.SourceFile) *lsproto.Range {
 	lspRange := l.converters.ToLSPRange(file, core.NewTextRange(start, end))
 	return &lspRange
 }
 
+func (l *LanguageService) createLspRangeFromRange(textRange core.TextRange, script Script) *lsproto.Range {
+	lspRange := l.converters.ToLSPRange(script, textRange)
+	return &lspRange
+}
+
 func (l *LanguageService) createLspPosition(position int, file *ast.SourceFile) lsproto.Position {
 	return l.converters.PositionToLineAndCharacter(file, core.TextPos(position))
 }

internal/project/project.go

@@ -9,7 +9,6 @@ import (
 	"github.com/microsoft/typescript-go/internal/collections"
 	"github.com/microsoft/typescript-go/internal/compiler"
 	"github.com/microsoft/typescript-go/internal/core"
-	"github.com/microsoft/typescript-go/internal/ls"
 	"github.com/microsoft/typescript-go/internal/lsp/lsproto"
 	"github.com/microsoft/typescript-go/internal/project/ata"
 	"github.com/microsoft/typescript-go/internal/project/logging"
@@ -49,8 +48,6 @@ const (
 	PendingReloadFull
 )
 
-var _ ls.Host = (*Project)(nil)
-
 // Project represents a TypeScript project.
 // If changing struct fields, also update the Clone method.
 type Project struct {
@@ -195,7 +192,6 @@ func (p *Project) ConfigFilePath() tspath.Path {
 	return p.configFilePath
 }
 
-// GetProgram implements ls.Host.
 func (p *Project) GetProgram() *compiler.Program {
 	return p.Program
 }

internal/project/session.go

@@ -367,7 +367,7 @@ func (s *Session) GetLanguageService(ctx context.Context, uri lsproto.DocumentUr
 	if project == nil {
 		return nil, fmt.Errorf("no project found for URI %s", uri)
 	}
-	return ls.NewLanguageService(project, snapshot.Converters()), nil
+	return ls.NewLanguageService(project.GetProgram(), snapshot), nil
 }
 
 func (s *Session) UpdateSnapshot(ctx context.Context, overlays map[tspath.Path]*overlay, change SnapshotChange) *Snapshot {

internal/project/snapshot.go

@@ -89,6 +89,22 @@ func (s *Snapshot) ID() uint64 {
 	return s.id
 }
 
+func (s *Snapshot) UseCaseSensitiveFileNames() bool {
+	return s.fs.fs.UseCaseSensitiveFileNames()
+}
+
+func (s *Snapshot) ReadFile(fileName string) (string, bool) {
+	handle := s.GetFile(fileName)
+	if handle == nil {
+		return "", false
+	}
+	return handle.Content(), true
+}
+
+func (s *Snapshot) FileExists(fileName string) bool {
+	return s.fs.fs.FileExists(fileName)
+}
+
 type APISnapshotRequest struct {
 	OpenProjects   *collections.Set[string]
 	CloseProjects  *collections.Set[tspath.Path]

internal/project/snapshotfs.go

@@ -1,6 +1,9 @@
 package project
 
 import (
+	"sync"
+
+	"github.com/microsoft/typescript-go/internal/collections"
 	"github.com/microsoft/typescript-go/internal/lsp/lsproto"
 	"github.com/microsoft/typescript-go/internal/project/dirty"
 	"github.com/microsoft/typescript-go/internal/tspath"
@@ -24,8 +27,11 @@ type snapshotFS struct {
 	fs        vfs.FS
 	overlays  map[tspath.Path]*overlay
 	diskFiles map[tspath.Path]*diskFile
+	readFiles collections.SyncMap[tspath.Path, memoizedDiskFile]
 }
 
+type memoizedDiskFile func() *diskFile
+
 func (s *snapshotFS) FS() vfs.FS {
 	return s.fs
 }
@@ -37,6 +43,15 @@ func (s *snapshotFS) GetFile(fileName string) FileHandle {
 	if file, ok := s.diskFiles[s.toPath(fileName)]; ok {
 		return file
 	}
+	newEntry := memoizedDiskFile(sync.OnceValue(func() *diskFile {
+		if contents, ok := s.fs.ReadFile(fileName); ok {
+			return newDiskFile(fileName, contents)
+		}
+		return nil
+	}))
+	if entry, ok := s.readFiles.LoadOrStore(s.toPath(fileName), newEntry); ok {
+		return entry()
+	}
 	return nil
 }