Refactor: move sourceFileMayBeEmitted to outputpaths and add forceDtsEmit parameter

Co-authored-by: andrewbranch <3277153+andrewbranch@users.noreply.github.com>

Author: Copilot

internal/checker/checker.go

@@ -14518,7 +14518,7 @@ func (c *Checker) resolveExternalModule(location *ast.Node, moduleReference stri
 						diagnostics.This_relative_import_path_is_unsafe_to_rewrite_because_it_looks_like_a_file_name_but_actually_resolves_to_0,
 						relativeToSourceFile,
 					)
-				} else if resolvedModule.ResolvedUsingTsExtension && !shouldRewrite && outputpaths.SourceFileMayBeEmitted(sourceFile, c.compilerOptions) {
+				} else if resolvedModule.ResolvedUsingTsExtension && !shouldRewrite && outputpaths.SourceFileMayBeEmitted(sourceFile, c.compilerOptions, false) {
 					c.error(
 						errorNode,
 						diagnostics.This_import_uses_a_0_extension_to_resolve_to_an_input_TypeScript_file_but_will_not_be_rewritten_during_emit_because_it_is_not_a_relative_path,
@@ -30410,8 +30410,8 @@ func (c *Checker) GetAliasedSymbol(symbol *ast.Symbol) *ast.Symbol {
 }
 
 func (c *Checker) shouldRewriteModuleSpecifier(specifier string) bool {
-	return c.compilerOptions.RewriteRelativeImportExtensions.IsTrue() && 
-		tspath.PathIsRelative(specifier) && 
-		!tspath.IsDeclarationFileName(specifier) && 
+	return c.compilerOptions.RewriteRelativeImportExtensions.IsTrue() &&
+		tspath.PathIsRelative(specifier) &&
+		!tspath.IsDeclarationFileName(specifier) &&
 		tspath.HasTSFileExtension(specifier)
 }

internal/compiler/emitter.go

@@ -2,7 +2,6 @@ package compiler
 
 import (
 	"encoding/base64"
-	"strings"
 
 	"github.com/microsoft/typescript-go/internal/ast"
 	"github.com/microsoft/typescript-go/internal/core"
@@ -297,37 +296,6 @@ func (e *emitter) getSourceMappingURL(mapOptions *core.CompilerOptions, sourceMa
 	return stringutil.EncodeURI(sourceMapFile)
 }
 
-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
-	if sourceFile.IsDeclarationFile {
-		return false
-	}
-
-	// !!! Source file from node_modules are not emitted. In Strada, this depends on module resolution and uses
-	// `sourceFilesFoundSearchingNodeModules` in `createProgram`. For now, we will just check for `/node_modules/` in
-	// the file name.
-	if strings.Contains(sourceFile.FileName(), "/node_modules/") {
-		return false
-	}
-
-	// forcing dts emit => file needs to be emitted
-	if forceDtsEmit {
-		return true
-	}
-
-	// !!! Source files from referenced projects are not emitted
-
-	// Any non json file should be emitted
-	if !ast.IsJsonSourceFile(sourceFile) {
-		return true
-	}
-
-	// !!! Should JSON input files be emitted
-	return false
-}
-
 func getSourceFilesToEmit(host printer.EmitHost, targetSourceFile *ast.SourceFile, forceDtsEmit bool) []*ast.SourceFile {
 	// !!! outFile not yet implemented, may be deprecated
 	var sourceFiles []*ast.SourceFile
@@ -337,7 +305,7 @@ func getSourceFilesToEmit(host printer.EmitHost, targetSourceFile *ast.SourceFil
 		sourceFiles = host.SourceFiles()
 	}
 	return core.Filter(sourceFiles, func(sourceFile *ast.SourceFile) bool {
-		return sourceFileMayBeEmitted(sourceFile, host, forceDtsEmit)
+		return outputpaths.SourceFileMayBeEmitted(sourceFile, host.Options(), forceDtsEmit)
 	})
 }
 

internal/compiler/program.go

@@ -710,9 +710,8 @@ func (p *Program) GetDefaultResolutionModeForFile(sourceFile ast.HasFileName) co
 func (p *Program) CommonSourceDirectory() string {
 	p.commonSourceDirectoryOnce.Do(func() {
 		var files []string
-		host := &emitHost{program: p}
 		for _, file := range p.files {
-			if sourceFileMayBeEmitted(file, host, false /*forceDtsEmit*/) {
+			if outputpaths.SourceFileMayBeEmitted(file, p.Options(), false /*forceDtsEmit*/) {
 				files = append(files, file.FileName())
 			}
 		}

internal/outputpaths/outputpaths.go

@@ -201,17 +201,33 @@ func getDeclarationEmitExtensionForPath(fileName string) string {
 }
 
 // SourceFileMayBeEmitted checks if a source file may be emitted by the compiler
-func SourceFileMayBeEmitted(sourceFile *ast.SourceFile, options *core.CompilerOptions) bool {
-	if options.NoEmit.IsTrue() || options.EmitDeclarationOnly.IsTrue() {
+func SourceFileMayBeEmitted(sourceFile *ast.SourceFile, options *core.CompilerOptions, forceDtsEmit bool) bool {
+	// !!! Js files are emitted only if option is enabled
+
+	// Declaration files are not emitted
+	if sourceFile.IsDeclarationFile {
 		return false
 	}
-	// Check if this source file is a declaration file
-	if tspath.IsDeclarationFileName(sourceFile.FileName()) {
+
+	// !!! Source file from node_modules are not emitted. In Strada, this depends on module resolution and uses
+	// `sourceFilesFoundSearchingNodeModules` in `createProgram`. For now, we will just check for `/node_modules/` in
+	// the file name.
+	if strings.Contains(sourceFile.FileName(), "/node_modules/") {
 		return false
 	}
-	// Check if this is a JS file and allowJs is disabled
-	if tspath.HasJSFileExtension(sourceFile.FileName()) && !options.AllowJs.IsTrue() {
-		return false
+
+	// forcing dts emit => file needs to be emitted
+	if forceDtsEmit {
+		return true
 	}
-	return true
+
+	// !!! Source files from referenced projects are not emitted
+
+	// Any non json file should be emitted
+	if !ast.IsJsonSourceFile(sourceFile) {
+		return true
+	}
+
+	// !!! Should JSON input files be emitted
+	return false
 }