Respect package.json "type" and module-format-specific file extensions in more module modes (microsoft#57896)

Author: andrewbranch

src/compiler/_namespaces/ts.ts

@@ -55,7 +55,7 @@ export * from "../transformers/generators";
 export * from "../transformers/module/module";
 export * from "../transformers/module/system";
 export * from "../transformers/module/esnextAnd2015";
-export * from "../transformers/module/node";
+export * from "../transformers/module/impliedNodeFormatDependent";
 export * from "../transformers/declarations/diagnostics";
 export * from "../transformers/declarations";
 export * from "../transformer";

src/compiler/checker.ts

@@ -967,6 +967,10 @@
         "category": "Error",
         "code": 1292
     },
+    "ESM syntax is not allowed in a CommonJS module when 'module' is set to 'preserve'.": {
+        "category": "Error",
+        "code": 1293
+    },
 
     "'with' statements are not allowed in an async function block.": {
         "category": "Error",

src/compiler/diagnosticMessages.json

@@ -130,6 +130,7 @@ import {
     getEmitFlags,
     getEmitHelpers,
     getEmitModuleKind,
+    getEmitModuleResolutionKind,
     getEmitScriptTarget,
     getExternalModuleName,
     getIdentifierTypeArguments,
@@ -800,6 +801,7 @@ export function emitFiles(resolver: EmitResolver, host: EmitHost, targetSourceFi
             newLine: compilerOptions.newLine,
             noEmitHelpers: compilerOptions.noEmitHelpers,
             module: getEmitModuleKind(compilerOptions),
+            moduleResolution: getEmitModuleResolutionKind(compilerOptions),
             target: getEmitScriptTarget(compilerOptions),
             sourceMap: compilerOptions.sourceMap,
             inlineSourceMap: compilerOptions.inlineSourceMap,
@@ -867,6 +869,7 @@ export function emitFiles(resolver: EmitResolver, host: EmitHost, targetSourceFi
                 newLine: compilerOptions.newLine,
                 noEmitHelpers: true,
                 module: compilerOptions.module,
+                moduleResolution: compilerOptions.moduleResolution,
                 target: compilerOptions.target,
                 sourceMap: !forceDtsEmit && compilerOptions.declarationMap,
                 inlineSourceMap: compilerOptions.inlineSourceMap,

src/compiler/emitter.ts

@@ -53,10 +53,12 @@ import {
     getAllAccessorDeclarations,
     getEmitFlags,
     getEmitHelpers,
+    getEmitModuleFormatOfFileWorker,
     getEmitModuleKind,
     getESModuleInterop,
     getExternalModuleName,
     getExternalModuleNameFromPath,
+    getImpliedNodeFormatForEmitWorker,
     getJSDocType,
     getJSDocTypeTag,
     getModifiers,
@@ -712,7 +714,7 @@ export function createExternalHelpersImportDeclarationIfNeeded(nodeFactory: Node
     if (compilerOptions.importHelpers && isEffectiveExternalModule(sourceFile, compilerOptions)) {
         let namedBindings: NamedImportBindings | undefined;
         const moduleKind = getEmitModuleKind(compilerOptions);
-        if ((moduleKind >= ModuleKind.ES2015 && moduleKind <= ModuleKind.ESNext) || sourceFile.impliedNodeFormat === ModuleKind.ESNext) {
+        if ((moduleKind >= ModuleKind.ES2015 && moduleKind <= ModuleKind.ESNext) || getImpliedNodeFormatForEmitWorker(sourceFile, compilerOptions) === ModuleKind.ESNext) {
             // use named imports
             const helpers = getEmitHelpers(sourceFile);
             if (helpers) {
@@ -769,10 +771,8 @@ export function getOrCreateExternalHelpersModuleNameIfNeeded(factory: NodeFactor
             return externalHelpersModuleName;
         }
 
-        const moduleKind = getEmitModuleKind(compilerOptions);
         let create = (hasExportStarsToExportValues || (getESModuleInterop(compilerOptions) && hasImportStarOrImportDefault))
-            && moduleKind !== ModuleKind.System
-            && (moduleKind < ModuleKind.ES2015 || node.impliedNodeFormat === ModuleKind.CommonJS);
+            && getEmitModuleFormatOfFileWorker(node, compilerOptions) < ModuleKind.System;
         if (!create) {
             const helpers = getEmitHelpers(node);
             if (helpers) {

src/compiler/factory/utilities.ts

@@ -36,9 +36,9 @@ import {
     getBaseFileName,
     GetCanonicalFileName,
     getConditions,
+    getDefaultResolutionModeForFileWorker,
     getDirectoryPath,
     getEmitModuleResolutionKind,
-    getModeForResolutionAtIndex,
     getModuleNameStringLiteralAt,
     getModuleSpecifierEndingPreference,
     getNodeModulePathParts,
@@ -136,12 +136,13 @@ export interface ModuleSpecifierPreferences {
     /**
      * @param syntaxImpliedNodeFormat Used when the import syntax implies ESM or CJS irrespective of the mode of the file.
      */
-    getAllowedEndingsInPreferredOrder(syntaxImpliedNodeFormat?: SourceFile["impliedNodeFormat"]): ModuleSpecifierEnding[];
+    getAllowedEndingsInPreferredOrder(syntaxImpliedNodeFormat?: ResolutionMode): ModuleSpecifierEnding[];
 }
 
 /** @internal */
 export function getModuleSpecifierPreferences(
     { importModuleSpecifierPreference, importModuleSpecifierEnding }: UserPreferences,
+    host: Pick<ModuleSpecifierResolutionHost, "getDefaultResolutionModeForFile">,
     compilerOptions: CompilerOptions,
     importingSourceFile: Pick<SourceFile, "fileName" | "impliedNodeFormat">,
     oldImportSpecifier?: string,
@@ -156,8 +157,10 @@ export function getModuleSpecifierPreferences(
             importModuleSpecifierPreference === "project-relative" ? RelativePreference.ExternalNonRelative :
             RelativePreference.Shortest,
         getAllowedEndingsInPreferredOrder: syntaxImpliedNodeFormat => {
-            const preferredEnding = syntaxImpliedNodeFormat !== importingSourceFile.impliedNodeFormat ? getPreferredEnding(syntaxImpliedNodeFormat) : filePreferredEnding;
-            if ((syntaxImpliedNodeFormat ?? importingSourceFile.impliedNodeFormat) === ModuleKind.ESNext) {
+            const impliedNodeFormat = getDefaultResolutionModeForFile(importingSourceFile, host, compilerOptions);
+            const preferredEnding = syntaxImpliedNodeFormat !== impliedNodeFormat ? getPreferredEnding(syntaxImpliedNodeFormat) : filePreferredEnding;
+            const moduleResolution = getEmitModuleResolutionKind(compilerOptions);
+            if ((syntaxImpliedNodeFormat ?? impliedNodeFormat) === ModuleKind.ESNext && ModuleResolutionKind.Node16 <= moduleResolution && moduleResolution <= ModuleResolutionKind.NodeNext) {
                 if (shouldAllowImportingTsExtension(compilerOptions, importingSourceFile.fileName)) {
                     return [ModuleSpecifierEnding.TsExtension, ModuleSpecifierEnding.JsExtension];
                 }
@@ -197,7 +200,7 @@ export function getModuleSpecifierPreferences(
         }
         return getModuleSpecifierEndingPreference(
             importModuleSpecifierEnding,
-            resolutionMode ?? importingSourceFile.impliedNodeFormat,
+            resolutionMode ?? getDefaultResolutionModeForFile(importingSourceFile, host, compilerOptions),
             compilerOptions,
             isFullSourceFile(importingSourceFile) ? importingSourceFile : undefined,
         );
@@ -218,7 +221,7 @@ export function updateModuleSpecifier(
     oldImportSpecifier: string,
     options: ModuleSpecifierOptions = {},
 ): string | undefined {
-    const res = getModuleSpecifierWorker(compilerOptions, importingSourceFile, importingSourceFileName, toFileName, host, getModuleSpecifierPreferences({}, compilerOptions, importingSourceFile, oldImportSpecifier), {}, options);
+    const res = getModuleSpecifierWorker(compilerOptions, importingSourceFile, importingSourceFileName, toFileName, host, getModuleSpecifierPreferences({}, host, compilerOptions, importingSourceFile, oldImportSpecifier), {}, options);
     if (res === oldImportSpecifier) return undefined;
     return res;
 }
@@ -238,7 +241,7 @@ export function getModuleSpecifier(
     host: ModuleSpecifierResolutionHost,
     options: ModuleSpecifierOptions = {},
 ): string {
-    return getModuleSpecifierWorker(compilerOptions, importingSourceFile, importingSourceFileName, toFileName, host, getModuleSpecifierPreferences({}, compilerOptions, importingSourceFile), {}, options);
+    return getModuleSpecifierWorker(compilerOptions, importingSourceFile, importingSourceFileName, toFileName, host, getModuleSpecifierPreferences({}, host, compilerOptions, importingSourceFile), {}, options);
 }
 
 /** @internal */
@@ -268,7 +271,7 @@ function getModuleSpecifierWorker(
     const info = getInfo(importingSourceFileName, host);
     const modulePaths = getAllModulePaths(info, toFileName, host, userPreferences, options);
     return firstDefined(modulePaths, modulePath => tryGetModuleNameAsNodeModule(modulePath, info, importingSourceFile, host, compilerOptions, userPreferences, /*packageNameOnly*/ undefined, options.overrideImportMode)) ||
-        getLocalModuleSpecifier(toFileName, info, compilerOptions, host, options.overrideImportMode || importingSourceFile.impliedNodeFormat, preferences);
+        getLocalModuleSpecifier(toFileName, info, compilerOptions, host, options.overrideImportMode || getDefaultResolutionModeForFile(importingSourceFile, host, compilerOptions), preferences);
 }
 
 /** @internal */
@@ -388,7 +391,7 @@ export function getLocalModuleSpecifierBetweenFileNames(
         compilerOptions,
         host,
         importMode,
-        getModuleSpecifierPreferences({}, compilerOptions, importingFile),
+        getModuleSpecifierPreferences({}, host, compilerOptions, importingFile),
     );
 }
 
@@ -402,15 +405,19 @@ function computeModuleSpecifiers(
     forAutoImport: boolean,
 ): readonly string[] {
     const info = getInfo(importingSourceFile.fileName, host);
-    const preferences = getModuleSpecifierPreferences(userPreferences, compilerOptions, importingSourceFile);
+    const preferences = getModuleSpecifierPreferences(userPreferences, host, compilerOptions, importingSourceFile);
     const existingSpecifier = isFullSourceFile(importingSourceFile) && forEach(modulePaths, modulePath =>
         forEach(
             host.getFileIncludeReasons().get(toPath(modulePath.path, host.getCurrentDirectory(), info.getCanonicalFileName)),
             reason => {
                 if (reason.kind !== FileIncludeKind.Import || reason.file !== importingSourceFile.path) return undefined;
                 // If the candidate import mode doesn't match the mode we're generating for, don't consider it
                 // TODO: maybe useful to keep around as an alternative option for certain contexts where the mode is overridable
-                if (importingSourceFile.impliedNodeFormat && importingSourceFile.impliedNodeFormat !== getModeForResolutionAtIndex(importingSourceFile, reason.index, compilerOptions)) return undefined;
+                const existingMode = host.getModeForResolutionAtIndex(importingSourceFile, reason.index);
+                const targetMode = options.overrideImportMode ?? host.getDefaultResolutionModeForFile(importingSourceFile);
+                if (existingMode !== targetMode && existingMode !== undefined && targetMode !== undefined) {
+                    return undefined;
+                }
                 const specifier = getModuleNameStringLiteralAt(importingSourceFile, reason.index).text;
                 // If the preference is for non relative and the module specifier is relative, ignore it
                 return preferences.relativePreference !== RelativePreference.NonRelative || !pathIsRelative(specifier) ?
@@ -1047,7 +1054,7 @@ function tryGetModuleNameAsNodeModule({ path, isRedirect }: ModulePath, { getCan
 
     // Simplify the full file path to something that can be resolved by Node.
 
-    const preferences = getModuleSpecifierPreferences(userPreferences, options, importingSourceFile);
+    const preferences = getModuleSpecifierPreferences(userPreferences, host, options, importingSourceFile);
     const allowedEndings = preferences.getAllowedEndingsInPreferredOrder();
     let moduleSpecifier = path;
     let isPackageRootPath = false;
@@ -1107,7 +1114,7 @@ function tryGetModuleNameAsNodeModule({ path, isRedirect }: ModulePath, { getCan
         const cachedPackageJson = host.getPackageJsonInfoCache?.()?.getPackageJsonInfo(packageJsonPath);
         if (isPackageJsonInfo(cachedPackageJson) || cachedPackageJson === undefined && host.fileExists(packageJsonPath)) {
             const packageJsonContent: Record<string, any> | undefined = cachedPackageJson?.contents.packageJsonContent || tryParseJson(host.readFile!(packageJsonPath)!);
-            const importMode = overrideMode || importingSourceFile.impliedNodeFormat;
+            const importMode = overrideMode || getDefaultResolutionModeForFile(importingSourceFile, host, options);
             if (getResolvePackageJsonExports(options)) {
                 // The package name that we found in node_modules could be different from the package
                 // name in the package.json content via url/filepath dependency specifiers. We need to
@@ -1302,3 +1309,7 @@ function getRelativePathIfInSameVolume(path: string, directoryPath: string, getC
 function isPathRelativeToParent(path: string): boolean {
     return startsWith(path, "..");
 }
+
+function getDefaultResolutionModeForFile(file: Pick<SourceFile, "fileName" | "impliedNodeFormat" | "packageJsonScope">, host: Pick<ModuleSpecifierResolutionHost, "getDefaultResolutionModeForFile">, compilerOptions: CompilerOptions) {
+    return isFullSourceFile(file) ? host.getDefaultResolutionModeForFile(file) : getDefaultResolutionModeForFileWorker(file, compilerOptions);
+}