Build mode

internal/api/server.go

@@ -8,6 +8,7 @@ import (
 	"io"
 	"strconv"
 	"sync"
+	"time"
 
 	"github.com/go-json-experiment/json"
 	"github.com/microsoft/typescript-go/internal/bundled"
@@ -472,3 +473,8 @@ func (s *Server) Stat(path string) vfs.FileInfo {
 func (s *Server) Remove(path string) error {
 	panic("unimplemented")
 }
+
+// Chtimes implements vfs.FS.
+func (s *Server) Chtimes(path string, aTime time.Time, mTime time.Time) error {
+	panic("unimplemented")
+}

internal/bundled/embed.go

@@ -161,6 +161,13 @@ func (vfs *wrappedFS) Remove(path string) error {
 	return vfs.fs.Remove(path)
 }
 
+func (vfs *wrappedFS) Chtimes(path string, aTime time.Time, mTime time.Time) error {
+	if _, ok := splitPath(path); ok {
+		panic("cannot change times on embedded file system")
+	}
+	return vfs.fs.Chtimes(path, aTime, mTime)
+}
+
 type fileInfo struct {
 	mode fs.FileMode
 	name string

internal/checker/checker.go

@@ -540,7 +540,7 @@ type Program interface {
 	SourceFileMayBeEmitted(sourceFile *ast.SourceFile, forceDtsEmit bool) bool
 	IsSourceFromProjectReference(path tspath.Path) bool
 	IsSourceFileDefaultLibrary(path tspath.Path) bool
-	GetSourceAndProjectReference(path tspath.Path) *tsoptions.SourceAndProjectReference
+	GetProjectReferenceFromOutputDts(path tspath.Path) *tsoptions.SourceOutputAndProjectReference
 	GetRedirectForResolution(file ast.HasFileName) *tsoptions.ParsedCommandLine
 	CommonSourceDirectory() string
 }
@@ -6483,7 +6483,7 @@ func (c *Checker) checkAliasSymbol(node *ast.Node) {
 		}
 		if c.compilerOptions.VerbatimModuleSyntax.IsTrue() && !ast.IsTypeOnlyImportOrExportDeclaration(node) && node.Flags&ast.NodeFlagsAmbient == 0 && targetFlags&ast.SymbolFlagsConstEnum != 0 {
 			constEnumDeclaration := target.ValueDeclaration
-			redirect := c.program.GetSourceAndProjectReference(ast.GetSourceFileOfNode(constEnumDeclaration).Path())
+			redirect := c.program.GetProjectReferenceFromOutputDts(ast.GetSourceFileOfNode(constEnumDeclaration).Path())
 			if constEnumDeclaration.Flags&ast.NodeFlagsAmbient != 0 && (redirect == nil || !redirect.Resolved.CompilerOptions().ShouldPreserveConstEnums()) {
 				c.error(node, diagnostics.Cannot_access_ambient_const_enums_when_0_is_enabled, c.getIsolatedModulesLikeFlagName())
 			}
@@ -7204,7 +7204,7 @@ func (c *Checker) checkConstEnumAccess(node *ast.Node, t *Type) {
 	if c.compilerOptions.IsolatedModules.IsTrue() || c.compilerOptions.VerbatimModuleSyntax.IsTrue() && ok && c.resolveName(node, ast.GetFirstIdentifier(node).Text(), ast.SymbolFlagsAlias, nil, false, true) == nil {
 		debug.Assert(t.symbol.Flags&ast.SymbolFlagsConstEnum != 0)
 		constEnumDeclaration := t.symbol.ValueDeclaration
-		redirect := c.program.GetSourceAndProjectReference(ast.GetSourceFileOfNode(constEnumDeclaration).Path())
+		redirect := c.program.GetProjectReferenceFromOutputDts(ast.GetSourceFileOfNode(constEnumDeclaration).Path())
 		if constEnumDeclaration.Flags&ast.NodeFlagsAmbient != 0 && !ast.IsValidTypeOnlyAliasUseSite(node) && (redirect == nil || !redirect.Resolved.CompilerOptions().ShouldPreserveConstEnums()) {
 			c.error(node, diagnostics.Cannot_access_ambient_const_enums_when_0_is_enabled, c.getIsolatedModulesLikeFlagName())
 		}
@@ -14636,7 +14636,7 @@ func (c *Checker) resolveExternalModule(location *ast.Node, moduleReference stri
 							}
 
 							var message *diagnostics.Message
-							if overrideHost != nil && overrideHost.Kind == ast.KindImportDeclaration && overrideHost.AsImportDeclaration().ImportClause.IsTypeOnly() {
+							if overrideHost != nil && overrideHost.Kind == ast.KindImportDeclaration && overrideHost.AsImportDeclaration().ImportClause != nil && overrideHost.AsImportDeclaration().ImportClause.IsTypeOnly() {
 								message = diagnostics.Type_only_import_of_an_ECMAScript_module_from_a_CommonJS_module_must_have_a_resolution_mode_attribute
 							} else if overrideHost != nil && overrideHost.Kind == ast.KindImportType {
 								message = diagnostics.Type_import_of_an_ECMAScript_module_from_a_CommonJS_module_must_have_a_resolution_mode_attribute
@@ -14689,7 +14689,7 @@ func (c *Checker) resolveExternalModule(location *ast.Node, moduleReference stri
 	if moduleNotFoundError != nil {
 		// See if this was possibly a projectReference redirect
 		if resolvedModule.IsResolved() {
-			redirect := c.program.GetOutputAndProjectReference(tspath.ToPath(resolvedModule.ResolvedFileName, c.program.GetCurrentDirectory(), c.program.UseCaseSensitiveFileNames()))
+			redirect := c.program.GetProjectReferenceFromSource(tspath.ToPath(resolvedModule.ResolvedFileName, c.program.GetCurrentDirectory(), c.program.UseCaseSensitiveFileNames()))
 			if redirect != nil && redirect.OutputDts != "" {
 				c.error(
 					errorNode,

internal/collections/syncset.go

@@ -11,8 +11,13 @@ func (s *SyncSet[T]) Has(key T) bool {
 	return ok
 }
 
+func (s *SyncSet[T]) AddIfAbsent(key T) bool {
+	_, loaded := s.m.LoadOrStore(key, struct{}{})
+	return !loaded
+}
+
 func (s *SyncSet[T]) Add(key T) {
-	s.m.Store(key, struct{}{})
+	s.AddIfAbsent(key)
 }
 
 func (s *SyncSet[T]) Delete(key T) {

internal/compiler/emitHost.go

@@ -78,8 +78,8 @@ func (host *emitHost) GetSourceOfProjectReferenceIfOutputIncluded(file ast.HasFi
 	return host.program.GetSourceOfProjectReferenceIfOutputIncluded(file)
 }
 
-func (host *emitHost) GetOutputAndProjectReference(path tspath.Path) *tsoptions.OutputDtsAndProjectReference {
-	return host.program.GetOutputAndProjectReference(path)
+func (host *emitHost) GetProjectReferenceFromSource(path tspath.Path) *tsoptions.SourceOutputAndProjectReference {
+	return host.program.GetProjectReferenceFromSource(path)
 }
 
 func (host *emitHost) GetRedirectTargets(path tspath.Path) []string {

internal/compiler/emitter.go

@@ -43,9 +43,6 @@ type emitter struct {
 }
 
 func (e *emitter) emit() {
-	if e.host.Options().ListEmittedFiles.IsTrue() {
-		e.emitResult.EmittedFiles = []string{}
-	}
 	// !!! tracing
 	e.emitJSFile(e.sourceFile, e.paths.JsFilePath(), e.paths.SourceMapFilePath())
 	e.emitDeclarationFile(e.sourceFile, e.paths.DeclarationFilePath(), e.paths.DeclarationMapPath())
@@ -268,7 +265,7 @@ func (e *emitter) printSourceFile(jsFilePath string, sourceMapFilePath string, s
 			err := e.host.WriteFile(sourceMapFilePath, sourceMap, false /*writeByteOrderMark*/)
 			if err != nil {
 				e.emitterDiagnostics.Add(ast.NewCompilerDiagnostic(diagnostics.Could_not_write_file_0_Colon_1, jsFilePath, err.Error()))
-			} else if e.emitResult.EmittedFiles != nil {
+			} else {
 				e.emitResult.EmittedFiles = append(e.emitResult.EmittedFiles, sourceMapFilePath)
 			}
 		}
@@ -292,7 +289,7 @@ func (e *emitter) printSourceFile(jsFilePath string, sourceMapFilePath string, s
 	}
 	if err != nil {
 		e.emitterDiagnostics.Add(ast.NewCompilerDiagnostic(diagnostics.Could_not_write_file_0_Colon_1, jsFilePath, err.Error()))
-	} else if e.emitResult.EmittedFiles != nil && !skippedDtsWrite {
+	} else if !skippedDtsWrite {
 		e.emitResult.EmittedFiles = append(e.emitResult.EmittedFiles, jsFilePath)
 	}
 
@@ -391,7 +388,7 @@ func (e *emitter) getSourceMappingURL(mapOptions *core.CompilerOptions, sourceMa
 
 type SourceFileMayBeEmittedHost interface {
 	Options() *core.CompilerOptions
-	GetOutputAndProjectReference(path tspath.Path) *tsoptions.OutputDtsAndProjectReference
+	GetProjectReferenceFromSource(path tspath.Path) *tsoptions.SourceOutputAndProjectReference
 	IsSourceFileFromExternalLibrary(file *ast.SourceFile) bool
 	GetCurrentDirectory() string
 	UseCaseSensitiveFileNames() bool
@@ -424,7 +421,7 @@ func sourceFileMayBeEmitted(sourceFile *ast.SourceFile, host SourceFileMayBeEmit
 
 	// Check other conditions for file emit
 	// Source files from referenced projects are not emitted
-	if host.GetOutputAndProjectReference(sourceFile.Path()) != nil {
+	if host.GetProjectReferenceFromSource(sourceFile.Path()) != nil {
 		return false
 	}
 

internal/compiler/fileInclude.go

@@ -8,6 +8,7 @@ import (
 	"github.com/microsoft/typescript-go/internal/core"
 	"github.com/microsoft/typescript-go/internal/diagnostics"
 	"github.com/microsoft/typescript-go/internal/module"
+	"github.com/microsoft/typescript-go/internal/scanner"
 	"github.com/microsoft/typescript-go/internal/tsoptions"
 	"github.com/microsoft/typescript-go/internal/tspath"
 )
@@ -57,7 +58,11 @@ type referenceFileLocation struct {
 
 func (r *referenceFileLocation) text() string {
 	if r.node != nil {
-		return r.node.Text()
+		if !ast.NodeIsSynthesized(r.node) {
+			return r.file.Text()[scanner.SkipTrivia(r.file.Text(), r.node.Loc.Pos()):r.node.End()]
+		} else {
+			return fmt.Sprintf(`"%s"`, r.node.Text())
+		}
 	} else {
 		return r.file.Text()[r.ref.Pos():r.ref.End()]
 	}

internal/compiler/fileloader.go

@@ -143,7 +143,10 @@ func processAllProgramFiles(
 
 	filesByPath := make(map[tspath.Path]*ast.SourceFile, totalFileCount)
 	loader.includeProcessor.fileIncludeReasons = make(map[tspath.Path][]*fileIncludeReason, totalFileCount)
-	outputFileToProjectReferenceSource := make(map[tspath.Path]string, totalFileCount)
+	var outputFileToProjectReferenceSource map[tspath.Path]string
+	if !opts.canUseProjectReferenceSource() {
+		outputFileToProjectReferenceSource = make(map[tspath.Path]string, totalFileCount)
+	}
 	resolvedModules := make(map[tspath.Path]module.ModeAwareCache[*module.ResolvedModule], totalFileCount+1)
 	typeResolutionsInFile := make(map[tspath.Path]module.ModeAwareCache[*module.ResolvedTypeReferenceDirective], totalFileCount)
 	sourceFileMetaDatas := make(map[tspath.Path]ast.SourceFileMetaData, totalFileCount)
@@ -454,9 +457,9 @@ func (p *fileLoader) resolveTypeReferenceDirectives(t *parseTask) {
 	typeResolutionsInFile := make(module.ModeAwareCache[*module.ResolvedTypeReferenceDirective], len(file.TypeReferenceDirectives))
 	var typeResolutionsTrace []string
 	for index, ref := range file.TypeReferenceDirectives {
-		redirect := p.projectReferenceFileMapper.getRedirectForResolution(file)
+		redirect, fileName := p.projectReferenceFileMapper.getRedirectForResolution(file)
 		resolutionMode := getModeForTypeReferenceDirectiveInFile(ref, file, meta, module.GetCompilerOptionsWithRedirect(p.opts.Config.CompilerOptions(), redirect))
-		resolved, trace := p.resolver.ResolveTypeReferenceDirective(ref.FileName, file.FileName(), resolutionMode, redirect)
+		resolved, trace := p.resolver.ResolveTypeReferenceDirective(ref.FileName, fileName, resolutionMode, redirect)
 		typeResolutionsInFile[module.ModeAwareCacheKey{Name: ref.FileName, Mode: resolutionMode}] = resolved
 		includeReason := &fileIncludeReason{
 			kind: fileIncludeKindTypeReferenceDirective,
@@ -498,7 +501,7 @@ func (p *fileLoader) resolveImportsAndModuleAugmentations(t *parseTask) {
 	isJavaScriptFile := ast.IsSourceFileJS(file)
 	isExternalModuleFile := ast.IsExternalModule(file)
 
-	redirect := p.projectReferenceFileMapper.getRedirectForResolution(file)
+	redirect, fileName := p.projectReferenceFileMapper.getRedirectForResolution(file)
 	optionsForFile := module.GetCompilerOptionsWithRedirect(p.opts.Config.CompilerOptions(), redirect)
 	if isJavaScriptFile || (!file.IsDeclarationFile && (optionsForFile.GetIsolatedModules() || isExternalModuleFile)) {
 		if optionsForFile.ImportHelpers.IsTrue() {
@@ -539,7 +542,7 @@ func (p *fileLoader) resolveImportsAndModuleAugmentations(t *parseTask) {
 			}
 
 			mode := getModeForUsageLocation(file.FileName(), meta, entry, optionsForFile)
-			resolvedModule, trace := p.resolver.ResolveModuleName(moduleName, file.FileName(), mode, redirect)
+			resolvedModule, trace := p.resolver.ResolveModuleName(moduleName, fileName, mode, redirect)
 			resolutionsInFile[module.ModeAwareCacheKey{Name: moduleName, Mode: mode}] = resolvedModule
 			resolutionsTrace = append(resolutionsTrace, trace...)
 
@@ -550,7 +553,7 @@ func (p *fileLoader) resolveImportsAndModuleAugmentations(t *parseTask) {
 			resolvedFileName := resolvedModule.ResolvedFileName
 			isFromNodeModulesSearch := resolvedModule.IsExternalLibraryImport
 			// Don't treat redirected files as JS files.
-			isJsFile := !tspath.FileExtensionIsOneOf(resolvedFileName, tspath.SupportedTSExtensionsWithJsonFlat) && p.projectReferenceFileMapper.getRedirectForResolution(ast.NewHasFileName(resolvedFileName, p.toPath(resolvedFileName))) == nil
+			isJsFile := !tspath.FileExtensionIsOneOf(resolvedFileName, tspath.SupportedTSExtensionsWithJsonFlat) && p.projectReferenceFileMapper.getRedirectParsedCommandLineForResolution(ast.NewHasFileName(resolvedFileName, p.toPath(resolvedFileName))) == nil
 			isJsFileFromNodeModules := isFromNodeModulesSearch && isJsFile && strings.Contains(resolvedFileName, "/node_modules/")
 
 			// add file to program only if:
@@ -610,19 +613,19 @@ func (p *fileLoader) pathForLibFile(name string) *LibFile {
 
 	path := tspath.CombinePaths(p.defaultLibraryPath, name)
 	replaced := false
-	if p.opts.Config.CompilerOptions().LibReplacement.IsTrue() {
+	if p.opts.Config.CompilerOptions().LibReplacement.IsTrue() && name != "lib.d.ts" {
 		libraryName := getLibraryNameFromLibFileName(name)
 		resolveFrom := getInferredLibraryNameResolveFrom(p.opts.Config.CompilerOptions(), p.opts.Host.GetCurrentDirectory(), name)
 		resolution, trace := p.resolver.ResolveModuleName(libraryName, resolveFrom, core.ModuleKindCommonJS, nil)
 		if resolution.IsResolved() {
 			path = resolution.ResolvedFileName
 			replaced = true
-			p.pathForLibFileResolutions.LoadOrStore(p.toPath(resolveFrom), &libResolution{
-				libraryName: libraryName,
-				resolution:  resolution,
-				trace:       trace,
-			})
 		}
+		p.pathForLibFileResolutions.LoadOrStore(p.toPath(resolveFrom), &libResolution{
+			libraryName: libraryName,
+			resolution:  resolution,
+			trace:       trace,
+		})
 	}
 
 	libPath, _ := p.pathForLibFileCache.LoadOrStore(name, &LibFile{name, path, replaced})

internal/compiler/processingDiagnostic.go

@@ -67,7 +67,7 @@ func (d *processingDiagnostic) toDiagnostic(program *Program) *ast.Diagnostic {
 
 func (d *processingDiagnostic) createDiagnosticExplainingFile(program *Program) *ast.Diagnostic {
 	diag := d.asIncludeExplainingDiagnostic()
-	var chain []*ast.Diagnostic
+	var includeDetails []*ast.Diagnostic
 	var relatedInfo []*ast.Diagnostic
 	var redirectInfo []*ast.Diagnostic
 	var preferredLocation *fileIncludeReason
@@ -90,15 +90,15 @@ func (d *processingDiagnostic) createDiagnosticExplainingFile(program *Program)
 		if !seenReasons.AddIfAbsent(includeReason) {
 			return
 		}
-		chain = append(chain, includeReason.toDiagnostic(program, false))
+		includeDetails = append(includeDetails, includeReason.toDiagnostic(program, false))
 		processRelatedInfo(includeReason)
 	}
 
 	// !!! todo sheetal caching
 
 	if diag.file != "" {
 		reasons := program.includeProcessor.fileIncludeReasons[diag.file]
-		chain = make([]*ast.Diagnostic, 0, len(reasons))
+		includeDetails = make([]*ast.Diagnostic, 0, len(reasons))
 		for _, reason := range reasons {
 			processInclude(reason)
 		}
@@ -107,9 +107,10 @@ func (d *processingDiagnostic) createDiagnosticExplainingFile(program *Program)
 	if diag.diagnosticReason != nil {
 		processInclude(diag.diagnosticReason)
 	}
-	if chain != nil && (preferredLocation == nil || seenReasons.Len() != 1) {
+	var chain []*ast.Diagnostic
+	if includeDetails != nil && (preferredLocation == nil || seenReasons.Len() != 1) {
 		fileReason := ast.NewCompilerDiagnostic(diagnostics.The_file_is_in_the_program_because_Colon)
-		fileReason.SetMessageChain(chain)
+		fileReason.SetMessageChain(includeDetails)
 		chain = []*ast.Diagnostic{fileReason}
 	}
 	if redirectInfo != nil {

internal/compiler/program.go

@@ -113,26 +113,27 @@ func (p *Program) GetSourceOfProjectReferenceIfOutputIncluded(file ast.HasFileNa
 	return file.FileName()
 }
 
-// GetOutputAndProjectReference implements checker.Program.
-func (p *Program) GetOutputAndProjectReference(path tspath.Path) *tsoptions.OutputDtsAndProjectReference {
-	return p.projectReferenceFileMapper.getOutputAndProjectReference(path)
+// GetProjectReferenceFromSource implements checker.Program.
+func (p *Program) GetProjectReferenceFromSource(path tspath.Path) *tsoptions.SourceOutputAndProjectReference {
+	return p.projectReferenceFileMapper.getProjectReferenceFromSource(path)
 }
 
 // IsSourceFromProjectReference implements checker.Program.
 func (p *Program) IsSourceFromProjectReference(path tspath.Path) bool {
 	return p.projectReferenceFileMapper.isSourceFromProjectReference(path)
 }
 
-func (p *Program) GetSourceAndProjectReference(path tspath.Path) *tsoptions.SourceAndProjectReference {
-	return p.projectReferenceFileMapper.getSourceAndProjectReference(path)
+func (p *Program) GetProjectReferenceFromOutputDts(path tspath.Path) *tsoptions.SourceOutputAndProjectReference {
+	return p.projectReferenceFileMapper.getProjectReferenceFromOutputDts(path)
 }
 
 func (p *Program) GetResolvedProjectReferenceFor(path tspath.Path) (*tsoptions.ParsedCommandLine, bool) {
 	return p.projectReferenceFileMapper.getResolvedReferenceFor(path)
 }
 
 func (p *Program) GetRedirectForResolution(file ast.HasFileName) *tsoptions.ParsedCommandLine {
-	return p.projectReferenceFileMapper.getRedirectForResolution(file)
+	redirect, _ := p.projectReferenceFileMapper.getRedirectForResolution(file)
+	return redirect
 }
 
 func (p *Program) GetParseFileRedirect(fileName string) string {
@@ -270,6 +271,7 @@ func equalCheckJSDirectives(d1 *ast.CheckJsDirective, d2 *ast.CheckJsDirective)
 
 func (p *Program) SourceFiles() []*ast.SourceFile { return p.files }
 func (p *Program) Options() *core.CompilerOptions { return p.opts.Config.CompilerOptions() }
+func (p *Program) GetRootFileNames() []string     { return p.opts.Config.FileNames() }
 func (p *Program) Host() CompilerHost             { return p.opts.Host }
 func (p *Program) GetConfigFileParsingDiagnostics() []*ast.Diagnostic {
 	return slices.Clip(p.opts.Config.GetConfigFileParsingDiagnostics())
@@ -862,7 +864,7 @@ func (p *Program) verifyProjectReferences() {
 		}
 		refOptions := config.CompilerOptions()
 		if !refOptions.Composite.IsTrue() || refOptions.NoEmit.IsTrue() {
-			if len(config.FileNames()) > 0 {
+			if len(p.opts.Config.FileNames()) > 0 {
 				if !refOptions.Composite.IsTrue() {
 					createDiagnosticForReference(parent, index, diagnostics.Referenced_project_0_must_have_setting_composite_Colon_true, ref.Path)
 				}
@@ -1268,11 +1270,10 @@ func (p *Program) CommonSourceDirectory() string {
 }
 
 type WriteFileData struct {
-	SourceMapUrlPos  int
-	BuildInfo        any
-	Diagnostics      []*ast.Diagnostic
-	DiffersOnlyInMap bool
-	SkippedDtsWrite  bool
+	SourceMapUrlPos int
+	BuildInfo       any
+	Diagnostics     []*ast.Diagnostic
+	SkippedDtsWrite bool
 }
 
 type EmitOptions struct {
@@ -1364,9 +1365,7 @@ func CombineEmitResults(results []*EmitResult) *EmitResult {
 			result.EmitSkipped = true
 		}
 		result.Diagnostics = append(result.Diagnostics, emitResult.Diagnostics...)
-		if emitResult.EmittedFiles != nil {
-			result.EmittedFiles = append(result.EmittedFiles, emitResult.EmittedFiles...)
-		}
+		result.EmittedFiles = append(result.EmittedFiles, emitResult.EmittedFiles...)
 		if emitResult.SourceMaps != nil {
 			result.SourceMaps = append(result.SourceMaps, emitResult.SourceMaps...)
 		}

internal/compiler/projectreferencedtsfakinghost.go

@@ -2,6 +2,7 @@ package compiler
 
 import (
 	"strings"
+	"time"
 
 	"github.com/microsoft/typescript-go/internal/collections"
 	"github.com/microsoft/typescript-go/internal/core"
@@ -82,6 +83,11 @@ func (fs *projectReferenceDtsFakingVfs) Remove(path string) error {
 	panic("should not be called by resolver")
 }
 
+// Chtimes implements vfs.FS.
+func (fs *projectReferenceDtsFakingVfs) Chtimes(path string, aTime time.Time, mTime time.Time) error {
+	panic("should not be called by resolver")
+}
+
 // DirectoryExists implements vfs.FS.
 func (fs *projectReferenceDtsFakingVfs) DirectoryExists(path string) bool {
 	if fs.projectReferenceFileMapper.opts.Host.FS().DirectoryExists(path) {
@@ -197,7 +203,7 @@ func (fs *projectReferenceDtsFakingVfs) fileOrDirectoryExistsUsingSource(fileOrD
 }
 
 func (fs *projectReferenceDtsFakingVfs) fileExistsIfProjectReferenceDts(file string) core.Tristate {
-	source := fs.projectReferenceFileMapper.getSourceAndProjectReference(fs.toPath(file))
+	source := fs.projectReferenceFileMapper.getProjectReferenceFromOutputDts(fs.toPath(file))
 	if source != nil {
 		return core.IfElse(fs.projectReferenceFileMapper.opts.Host.FS().FileExists(source.Source), core.TSTrue, core.TSFalse)
 	}