Respect package.json "type" and module-format-specific file extensions in more module modes

src/compiler/_namespaces/ts.ts

@@ -54,7 +54,7 @@ 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/diagnosticMessages.json

@@ -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/emitter.ts

@@ -130,6 +130,7 @@ import {
     getEmitFlags,
     getEmitHelpers,
     getEmitModuleKind,
+    getEmitModuleResolutionKind,
     getEmitScriptTarget,
     getExternalModuleName,
     getIdentifierTypeArguments,
@@ -799,6 +800,7 @@ 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,
@@ -866,6 +868,7 @@ 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/factory/utilities.ts

@@ -53,6 +53,7 @@ import {
     getAllAccessorDeclarations,
     getEmitFlags,
     getEmitHelpers,
+    getEmitModuleFormatOfFile,
     getEmitModuleKind,
     getESModuleInterop,
     getExternalModuleName,
@@ -71,6 +72,7 @@ import {
     HasIllegalTypeParameters,
     Identifier,
     idText,
+    impliedNodeFormatForEmit,
     ImportCall,
     ImportDeclaration,
     ImportEqualsDeclaration,
@@ -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) || impliedNodeFormatForEmit(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);
+            && getEmitModuleFormatOfFile(node, compilerOptions) < ModuleKind.System;
         if (!create) {
             const helpers = getEmitHelpers(node);
             if (helpers) {

src/compiler/moduleSpecifiers.ts

@@ -35,6 +35,7 @@ import {
     getBaseFileName,
     GetCanonicalFileName,
     getConditions,
+    getDefaultResolutionModeForFile,
     getDirectoryPath,
     getEmitModuleResolutionKind,
     getModeForResolutionAtIndex,
@@ -134,7 +135,7 @@ 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 */
@@ -154,8 +155,10 @@ 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, 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];
                 }
@@ -195,7 +198,7 @@ export function getModuleSpecifierPreferences(
         }
         return getModuleSpecifierEndingPreference(
             importModuleSpecifierEnding,
-            resolutionMode ?? importingSourceFile.impliedNodeFormat,
+            resolutionMode ?? getDefaultResolutionModeForFile(importingSourceFile, compilerOptions),
             compilerOptions,
             importingSourceFile,
         );
@@ -266,7 +269,7 @@ 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, compilerOptions), preferences);
 }
 
 /** @internal */
@@ -388,7 +391,11 @@ function computeModuleSpecifiers(
                 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 = getModeForResolutionAtIndex(importingSourceFile, reason.index, compilerOptions);
+                const targetMode = options.overrideImportMode ?? getDefaultResolutionModeForFile(importingSourceFile, compilerOptions);
+                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) ?
@@ -1078,7 +1085,7 @@ 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, 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