Add ESNext transform

Author: rbuckton

internal/ast/utilities.go

@@ -75,6 +75,10 @@ func NodeIsSynthesized(node *Node) bool {
 	return PositionIsSynthesized(node.Loc.Pos()) || PositionIsSynthesized(node.Loc.End())
 }
 
+func RangeIsSynthesized(loc core.TextRange) bool {
+	return PositionIsSynthesized(loc.Pos()) || PositionIsSynthesized(loc.End())
+}
+
 // Determines whether a position is synthetic
 func PositionIsSynthesized(pos int) bool {
 	return pos < 0

internal/compiler/emitHost.go

@@ -7,28 +7,7 @@ import (
 	"github.com/microsoft/typescript-go/internal/tspath"
 )
 
-type WriteFileData struct {
-	SourceMapUrlPos int
-	// BuildInfo BuildInfo
-	Diagnostics      []*ast.Diagnostic
-	DiffersOnlyInMap bool
-	SkippedDtsWrite  bool
-}
-
-// NOTE: EmitHost operations must be thread-safe
-type EmitHost interface {
-	Options() *core.CompilerOptions
-	SourceFiles() []*ast.SourceFile
-	UseCaseSensitiveFileNames() bool
-	GetCurrentDirectory() string
-	CommonSourceDirectory() string
-	IsEmitBlocked(file string) bool
-	WriteFile(fileName string, text string, writeByteOrderMark bool, relatedSourceFiles []*ast.SourceFile, data *WriteFileData) error
-	GetSourceFileMetaData(path tspath.Path) *ast.SourceFileMetaData
-	GetEmitResolver(file *ast.SourceFile, skipDiagnostics bool) printer.EmitResolver
-}
-
-var _ EmitHost = (*emitHost)(nil)
+var _ printer.EmitHost = (*emitHost)(nil)
 
 // NOTE: emitHost operations must be thread-safe
 type emitHost struct {
@@ -48,7 +27,7 @@ func (host *emitHost) IsEmitBlocked(file string) bool {
 	return false
 }
 
-func (host *emitHost) WriteFile(fileName string, text string, writeByteOrderMark bool, _ []*ast.SourceFile, _ *WriteFileData) error {
+func (host *emitHost) WriteFile(fileName string, text string, writeByteOrderMark bool, _ []*ast.SourceFile, _ *printer.WriteFileData) error {
 	return host.program.host.FS().WriteFile(fileName, text, writeByteOrderMark)
 }
 

internal/compiler/emitter.go

@@ -5,7 +5,6 @@ import (
 	"strings"
 
 	"github.com/microsoft/typescript-go/internal/ast"
-	"github.com/microsoft/typescript-go/internal/binder"
 	"github.com/microsoft/typescript-go/internal/core"
 	"github.com/microsoft/typescript-go/internal/diagnostics"
 	"github.com/microsoft/typescript-go/internal/printer"
@@ -25,7 +24,7 @@ const (
 )
 
 type emitter struct {
-	host               EmitHost
+	host               printer.EmitHost
 	emitOnly           emitOnly
 	emittedFilesList   []string
 	emitterDiagnostics ast.DiagnosticsCollection
@@ -43,61 +42,6 @@ func (e *emitter) emit() {
 	e.emitBuildInfo(e.paths.buildInfoPath)
 }
 
-func (e *emitter) getModuleTransformer(emitContext *printer.EmitContext, resolver binder.ReferenceResolver, sourceFileMetaDataProvider printer.SourceFileMetaDataProvider) *transformers.Transformer {
-	options := e.host.Options()
-
-	switch options.GetEmitModuleKind() {
-	case core.ModuleKindPreserve:
-		// `ESModuleTransformer` contains logic for preserving CJS input syntax in `--module preserve`
-		return transformers.NewESModuleTransformer(emitContext, options, resolver, sourceFileMetaDataProvider)
-
-	case core.ModuleKindESNext,
-		core.ModuleKindES2022,
-		core.ModuleKindES2020,
-		core.ModuleKindES2015,
-		core.ModuleKindNode16,
-		core.ModuleKindNodeNext,
-		core.ModuleKindCommonJS:
-		return transformers.NewImpliedModuleTransformer(emitContext, options, resolver, sourceFileMetaDataProvider)
-
-	default:
-		return transformers.NewCommonJSModuleTransformer(emitContext, options, resolver, sourceFileMetaDataProvider)
-	}
-}
-
-func (e *emitter) getScriptTransformers(emitContext *printer.EmitContext, sourceFile *ast.SourceFile) []*transformers.Transformer {
-	var tx []*transformers.Transformer
-	options := e.host.Options()
-
-	// JS files don't use reference calculations as they don't do import elision, no need to calculate it
-	importElisionEnabled := !options.VerbatimModuleSyntax.IsTrue() && !ast.IsInJSFile(sourceFile.AsNode())
-
-	var emitResolver printer.EmitResolver
-	var referenceResolver binder.ReferenceResolver
-	if importElisionEnabled {
-		emitResolver = e.host.GetEmitResolver(sourceFile, false /*skipDiagnostics*/) // !!! conditionally skip diagnostics
-		emitResolver.MarkLinkedReferencesRecursively(sourceFile)
-		referenceResolver = emitResolver
-	} else {
-		referenceResolver = binder.NewReferenceResolver(options, binder.ReferenceResolverHooks{})
-	}
-
-	// erase types
-	tx = append(tx, transformers.NewTypeEraserTransformer(emitContext, options))
-
-	// elide imports
-	if importElisionEnabled {
-		tx = append(tx, transformers.NewImportElisionTransformer(emitContext, options, emitResolver))
-	}
-
-	// transform `enum`, `namespace`, and parameter properties
-	tx = append(tx, transformers.NewRuntimeSyntaxTransformer(emitContext, options, referenceResolver))
-
-	// transform module syntax
-	tx = append(tx, e.getModuleTransformer(emitContext, referenceResolver, e.host))
-	return tx
-}
-
 func (e *emitter) emitJSFile(sourceFile *ast.SourceFile, jsFilePath string, sourceMapFilePath string) {
 	options := e.host.Options()
 
@@ -110,7 +54,7 @@ func (e *emitter) emitJSFile(sourceFile *ast.SourceFile, jsFilePath string, sour
 	}
 
 	emitContext := printer.NewEmitContext()
-	for _, transformer := range e.getScriptTransformers(emitContext, sourceFile) {
+	for _, transformer := range transformers.GetScriptTransformers(emitContext, e.host, sourceFile) {
 		sourceFile = transformer.TransformSourceFile(sourceFile)
 	}
 
@@ -147,7 +91,7 @@ func (e *emitter) emitBuildInfo(buildInfoPath string) {
 	// !!!
 }
 
-func (e *emitter) printSourceFile(jsFilePath string, sourceMapFilePath string, sourceFile *ast.SourceFile, printer *printer.Printer) bool {
+func (e *emitter) printSourceFile(jsFilePath string, sourceMapFilePath string, sourceFile *ast.SourceFile, printer_ *printer.Printer) bool {
 	// !!! sourceMapGenerator
 	options := e.host.Options()
 	var sourceMapGenerator *sourcemap.Generator
@@ -166,7 +110,7 @@ func (e *emitter) printSourceFile(jsFilePath string, sourceMapFilePath string, s
 	// !!! bundles not implemented, may be deprecated
 	sourceFiles := []*ast.SourceFile{sourceFile}
 
-	printer.Write(sourceFile.AsNode(), sourceFile, e.writer, sourceMapGenerator)
+	printer_.Write(sourceFile.AsNode(), sourceFile, e.writer, sourceMapGenerator)
 
 	sourceMapUrlPos := -1
 	if sourceMapGenerator != nil {
@@ -208,7 +152,7 @@ func (e *emitter) printSourceFile(jsFilePath string, sourceMapFilePath string, s
 
 	// Write the output file
 	text := e.writer.String()
-	data := &WriteFileData{SourceMapUrlPos: sourceMapUrlPos} // !!! transform diagnostics
+	data := &printer.WriteFileData{SourceMapUrlPos: sourceMapUrlPos} // !!! transform diagnostics
 	err := e.host.WriteFile(jsFilePath, text, e.host.Options().EmitBOM.IsTrue(), sourceFiles, data)
 	if err != nil {
 		e.emitterDiagnostics.Add(ast.NewCompilerDiagnostic(diagnostics.Could_not_write_file_0_Colon_1, jsFilePath, err.Error()))
@@ -232,7 +176,7 @@ func getSourceFilePathInNewDir(fileName string, newDirPath string, currentDirect
 	return tspath.CombinePaths(newDirPath, sourceFilePath)
 }
 
-func getOwnEmitOutputFilePath(fileName string, host EmitHost, extension string) string {
+func getOwnEmitOutputFilePath(fileName string, host printer.EmitHost, extension string) string {
 	compilerOptions := host.Options()
 	var emitOutputFilePathWithoutExtension string
 	if len(compilerOptions.OutDir) > 0 {
@@ -341,7 +285,7 @@ func (e *emitter) getSourceMappingURL(mapOptions *core.CompilerOptions, sourceMa
 	return stringutil.EncodeURI(sourceMapFile)
 }
 
-func getDeclarationEmitOutputFilePath(file string, host EmitHost) string {
+func getDeclarationEmitOutputFilePath(file string, host printer.EmitHost) string {
 	// !!!
 	return ""
 }
@@ -354,7 +298,7 @@ type outputPaths struct {
 	buildInfoPath       string
 }
 
-func getOutputPathsFor(sourceFile *ast.SourceFile, host EmitHost, forceDtsEmit bool) *outputPaths {
+func getOutputPathsFor(sourceFile *ast.SourceFile, host printer.EmitHost, forceDtsEmit bool) *outputPaths {
 	options := host.Options()
 	// !!! bundle not implemented, may be deprecated
 	ownOutputFilePath := getOwnEmitOutputFilePath(sourceFile.FileName(), host, core.GetOutputExtension(sourceFile.FileName(), options.Jsx))
@@ -381,7 +325,7 @@ func getOutputPathsFor(sourceFile *ast.SourceFile, host EmitHost, forceDtsEmit b
 	return paths
 }
 
-func forEachEmittedFile(host EmitHost, action func(emitFileNames *outputPaths, sourceFile *ast.SourceFile) bool, sourceFiles []*ast.SourceFile, options *EmitOptions) bool {
+func forEachEmittedFile(host printer.EmitHost, action func(emitFileNames *outputPaths, sourceFile *ast.SourceFile) bool, sourceFiles []*ast.SourceFile, options *EmitOptions) bool {
 	// !!! outFile not yet implemented, may be deprecated
 	for _, sourceFile := range sourceFiles {
 		if action(getOutputPathsFor(sourceFile, host, options.forceDtsEmit), sourceFile) {
@@ -391,7 +335,7 @@ func forEachEmittedFile(host EmitHost, action func(emitFileNames *outputPaths, s
 	return false
 }
 
-func sourceFileMayBeEmitted(sourceFile *ast.SourceFile, host EmitHost, forceDtsEmit bool) bool {
+func sourceFileMayBeEmitted(sourceFile *ast.SourceFile, host printer.EmitHost, forceDtsEmit bool) bool {
 	// !!! Js files are emitted only if option is enabled
 
 	// Declaration files are not emitted
@@ -422,7 +366,7 @@ func sourceFileMayBeEmitted(sourceFile *ast.SourceFile, host EmitHost, forceDtsE
 	return false
 }
 
-func getSourceFilesToEmit(host EmitHost, targetSourceFile *ast.SourceFile, forceDtsEmit bool) []*ast.SourceFile {
+func getSourceFilesToEmit(host printer.EmitHost, targetSourceFile *ast.SourceFile, forceDtsEmit bool) []*ast.SourceFile {
 	// !!! outFile not yet implemented, may be deprecated
 	var sourceFiles []*ast.SourceFile
 	if targetSourceFile != nil {

internal/printer/emitcontext.go

@@ -19,6 +19,8 @@ type EmitContext struct {
 	textSource    map[*ast.StringLiteralNode]*ast.Node
 	original      map[*ast.Node]*ast.Node
 	emitNodes     core.LinkStore[*ast.Node, emitNode]
+	assignedName  map[*ast.Node]*ast.Expression
+	classThis     map[*ast.Node]*ast.IdentifierNode
 	varScopeStack core.Stack[*varScope]
 	letScopeStack core.Stack[*varScope]
 	emitHelpers   collections.OrderedSet[*EmitHelper]
@@ -575,6 +577,28 @@ func (c *EmitContext) SetTokenSourceMapRange(node *ast.Node, kind ast.Kind, loc
 	emitNode.tokenSourceMapRanges[kind] = loc
 }
 
+func (c *EmitContext) AssignedName(node *ast.Node) *ast.Expression {
+	return c.assignedName[node]
+}
+
+func (c *EmitContext) SetAssignedName(node *ast.Node, name *ast.Expression) {
+	if c.assignedName == nil {
+		c.assignedName = make(map[*ast.Node]*ast.Expression)
+	}
+	c.assignedName[node] = name
+}
+
+func (c *EmitContext) ClassThis(node *ast.Node) *ast.Expression {
+	return c.classThis[node]
+}
+
+func (c *EmitContext) SetClassThis(node *ast.Node, classThis *ast.IdentifierNode) {
+	if c.classThis == nil {
+		c.classThis = make(map[*ast.Node]*ast.Expression)
+	}
+	c.classThis[node] = classThis
+}
+
 func (c *EmitContext) RequestEmitHelper(helper *EmitHelper) {
 	if helper.Scoped {
 		panic("Cannot request a scoped emit helper")
@@ -659,6 +683,13 @@ func (c *EmitContext) HasRecordedExternalHelpers(node *ast.SourceFile) bool {
 	return false
 }
 
+func (c *EmitContext) IsCallToHelper(firstSegment *ast.Expression, helperName string) bool {
+	return ast.IsCallExpression(firstSegment) &&
+		ast.IsIdentifier(firstSegment.Expression()) &&
+		(c.EmitFlags(firstSegment.Expression())&EFHelperName) != 0 &&
+		firstSegment.Expression().Text() == helperName
+}
+
 //
 // Visitor Hooks
 //

internal/printer/emithost.go

@@ -0,0 +1,29 @@
+package printer
+
+import (
+	"github.com/microsoft/typescript-go/internal/ast"
+	"github.com/microsoft/typescript-go/internal/core"
+	"github.com/microsoft/typescript-go/internal/tspath"
+)
+
+type WriteFileData struct {
+	SourceMapUrlPos int
+	// BuildInfo BuildInfo
+	Diagnostics      []*ast.Diagnostic
+	DiffersOnlyInMap bool
+	SkippedDtsWrite  bool
+}
+
+// NOTE: EmitHost operations must be thread-safe
+type EmitHost interface {
+	SourceFileMetaDataProvider
+	Options() *core.CompilerOptions
+	SourceFiles() []*ast.SourceFile
+	UseCaseSensitiveFileNames() bool
+	GetCurrentDirectory() string
+	CommonSourceDirectory() string
+	IsEmitBlocked(file string) bool
+	WriteFile(fileName string, text string, writeByteOrderMark bool, relatedSourceFiles []*ast.SourceFile, data *WriteFileData) error
+	GetSourceFileMetaData(path tspath.Path) *ast.SourceFileMetaData
+	GetEmitResolver(file *ast.SourceFile, skipDiagnostics bool) EmitResolver
+}