Silence “Cannot require an ESM file” error in type-only imports (and ImportTypeNodes)

src/compiler/checker.ts

@@ -4865,19 +4865,19 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
         const moduleResolutionKind = getEmitModuleResolutionKind(compilerOptions);
         const resolvedModule = getResolvedModule(currentSourceFile, moduleReference, mode);
         const resolutionDiagnostic = resolvedModule && getResolutionDiagnostic(compilerOptions, resolvedModule, currentSourceFile);
-        const sourceFile = resolvedModule
+        const targetSourceFile = resolvedModule
             && (!resolutionDiagnostic || resolutionDiagnostic === Diagnostics.Module_0_was_resolved_to_1_but_jsx_is_not_set)
             && host.getSourceFile(resolvedModule.resolvedFileName);
-        if (sourceFile) {
+        if (targetSourceFile) {
             // If there's a resolutionDiagnostic we need to report it even if a sourceFile is found.
             if (resolutionDiagnostic) {
                 error(errorNode, resolutionDiagnostic, moduleReference, resolvedModule.resolvedFileName);
             }
 
+            const importOrExport =
+                findAncestor(location, isImportDeclaration)?.importClause ||
+                findAncestor(location, or(isImportEqualsDeclaration, isExportDeclaration));
             if (resolvedModule.resolvedUsingTsExtension && isDeclarationFileName(moduleReference)) {
-                const importOrExport =
-                    findAncestor(location, isImportDeclaration)?.importClause ||
-                    findAncestor(location, or(isImportEqualsDeclaration, isExportDeclaration));
                 if (importOrExport && !importOrExport.isTypeOnly || findAncestor(location, isImportCall)) {
                     error(
                         errorNode,
@@ -4890,17 +4890,13 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
                 error(errorNode, Diagnostics.An_import_path_can_only_end_with_a_0_extension_when_allowImportingTsExtensions_is_enabled, tsExtension);
             }
 
-            if (sourceFile.symbol) {
+            if (targetSourceFile.symbol) {
                 if (resolvedModule.isExternalLibraryImport && !resolutionExtensionIsTSOrJson(resolvedModule.extension)) {
                     errorOnImplicitAnyModule(/*isError*/ false, errorNode, currentSourceFile, mode, resolvedModule, moduleReference);
                 }
-                if (moduleResolutionKind === ModuleResolutionKind.Node16 || moduleResolutionKind === ModuleResolutionKind.NodeNext) {
+                if (ModuleResolutionKind.Node16 <= moduleResolutionKind && moduleResolutionKind <= ModuleResolutionKind.NodeNext && !importOrExport?.isTypeOnly && !findAncestor(location, isImportTypeNode)) {
                     const isSyncImport = (currentSourceFile.impliedNodeFormat === ModuleKind.CommonJS && !findAncestor(location, isImportCall)) || !!findAncestor(location, isImportEqualsDeclaration);
-                    const overrideClauseHost = findAncestor(location, l => isImportTypeNode(l) || isExportDeclaration(l) || isImportDeclaration(l)) as ImportTypeNode | ImportDeclaration | ExportDeclaration | undefined;
-                    const overrideClause = overrideClauseHost && isImportTypeNode(overrideClauseHost) ? overrideClauseHost.assertions?.assertClause : overrideClauseHost?.assertClause;
-                    // An override clause will take effect for type-only imports and import types, and allows importing the types across formats, regardless of
-                    // normal mode restrictions
-                    if (isSyncImport && sourceFile.impliedNodeFormat === ModuleKind.ESNext && !getResolutionModeOverrideForClause(overrideClause)) {
+                    if (isSyncImport && targetSourceFile.impliedNodeFormat === ModuleKind.ESNext) {
                         if (findAncestor(location, isImportEqualsDeclaration)) {
                             // ImportEquals in a ESM file resolving to another ESM file
                             error(errorNode, Diagnostics.Module_0_cannot_be_imported_using_this_construct_The_specifier_only_resolves_to_an_ES_module_which_cannot_be_imported_with_require_Use_an_ECMAScript_import_instead, moduleReference);
@@ -4949,11 +4945,11 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
                     }
                 }
                 // merged symbol is module declaration symbol combined with all augmentations
-                return getMergedSymbol(sourceFile.symbol);
+                return getMergedSymbol(targetSourceFile.symbol);
             }
             if (moduleNotFoundError) {
                 // report errors only if it was requested
-                error(errorNode, Diagnostics.File_0_is_not_a_module, sourceFile.fileName);
+                error(errorNode, Diagnostics.File_0_is_not_a_module, targetSourceFile.fileName);
             }
             return undefined;
         }

tests/baselines/reference/importTypeResolvingToESMFromCJS.js

@@ -0,0 +1,12 @@
+//// [tests/cases/compiler/importTypeResolvingToESMFromCJS.ts] ////
+
+//// [types.d.mts]
+export interface A {}
+
+//// [main.cts]
+type A = import("./types.mjs").A;
+
+
+//// [main.cjs]
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });

tests/baselines/reference/importTypeResolvingToESMFromCJS.symbols

@@ -0,0 +1,9 @@
+=== /types.d.mts ===
+export interface A {}
+>A : Symbol(A, Decl(types.d.mts, 0, 0))
+
+=== /main.cts ===
+type A = import("./types.mjs").A;
+>A : Symbol(A, Decl(main.cts, 0, 0))
+>A : Symbol(A, Decl(types.d.mts, 0, 0))
+

tests/baselines/reference/importTypeResolvingToESMFromCJS.types

@@ -0,0 +1,8 @@
+=== /types.d.mts ===
+
+export interface A {}
+
+=== /main.cts ===
+type A = import("./types.mjs").A;
+>A : import("/types", { assert: { "resolution-mode": "import" } }).A
+

tests/baselines/reference/tsbuildWatch/moduleResolution/resolves-specifier-in-output-declaration-file-from-referenced-project-correctly-with-cts-and-mts-extensions.js

@@ -338,13 +338,7 @@ File '/user/username/projects/myproject/packages/pkg2/build/const.d.cts' exists
 File '/a/lib/package.json' does not exist.
 File '/a/package.json' does not exist.
 File '/package.json' does not exist.
-packages/pkg1/index.ts:1:29 - error TS1479: The current file is a CommonJS module whose imports will produce 'require' calls; however, the referenced file is an ECMAScript module and cannot be imported with 'require'. Consider writing a dynamic 'import("pkg2")' call instead.
-  To convert this file to an ECMAScript module, change its file extension to '.mts' or create a local package.json file with `{ "type": "module" }`.
-
-1 import type { TheNum } from 'pkg2'
-                              ~~~~~~
-
-[12:01:16 AM] Found 1 error. Watching for file changes.
+[12:01:20 AM] Found 0 errors. Watching for file changes.
 
 
 
@@ -365,6 +359,13 @@ Shape signatures in builder refreshed for::
 
 exitCode:: ExitStatus.undefined
 
+//// [/user/username/projects/myproject/packages/pkg1/build/index.js]
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+exports.theNum = void 0;
+exports.theNum = 42;
+
+
 
 Change:: removes those errors when a package file is changed back
 
@@ -375,11 +376,11 @@ Input::
 
 Output::
 >> Screen clear
-[12:01:20 AM] File change detected. Starting incremental compilation...
+[12:01:24 AM] File change detected. Starting incremental compilation...
 
-[12:01:21 AM] Project 'packages/pkg1/tsconfig.json' is out of date because output 'packages/pkg1/build/index.js' is older than input 'packages/pkg1/package.json'
+[12:01:25 AM] Project 'packages/pkg1/tsconfig.json' is out of date because output 'packages/pkg1/build/index.js' is older than input 'packages/pkg1/package.json'
 
-[12:01:22 AM] Building project '/user/username/projects/myproject/packages/pkg1/tsconfig.json'...
+[12:01:26 AM] Building project '/user/username/projects/myproject/packages/pkg1/tsconfig.json'...
 
 Found 'package.json' at '/user/username/projects/myproject/packages/pkg1/package.json'.
 ======== Resolving module 'pkg2' from '/user/username/projects/myproject/packages/pkg1/index.ts'. ========
@@ -417,7 +418,7 @@ File '/user/username/projects/myproject/packages/pkg2/build/const.d.cts' exists
 File '/a/lib/package.json' does not exist.
 File '/a/package.json' does not exist.
 File '/package.json' does not exist.
-[12:01:27 AM] Found 0 errors. Watching for file changes.
+[12:01:31 AM] Found 0 errors. Watching for file changes.
 
 
 
@@ -438,7 +439,10 @@ Shape signatures in builder refreshed for::
 
 exitCode:: ExitStatus.undefined
 
-//// [/user/username/projects/myproject/packages/pkg1/build/index.js] file written with same contents
+//// [/user/username/projects/myproject/packages/pkg1/build/index.js]
+export const theNum = 42;
+
+
 
 Change:: reports import errors after change to package file
 
@@ -449,11 +453,11 @@ Input::
 
 Output::
 >> Screen clear
-[12:01:31 AM] File change detected. Starting incremental compilation...
+[12:01:35 AM] File change detected. Starting incremental compilation...
 
-[12:01:32 AM] Project 'packages/pkg1/tsconfig.json' is out of date because output 'packages/pkg1/build/index.js' is older than input 'packages/pkg1/package.json'
+[12:01:36 AM] Project 'packages/pkg1/tsconfig.json' is out of date because output 'packages/pkg1/build/index.js' is older than input 'packages/pkg1/package.json'
 
-[12:01:33 AM] Building project '/user/username/projects/myproject/packages/pkg1/tsconfig.json'...
+[12:01:37 AM] Building project '/user/username/projects/myproject/packages/pkg1/tsconfig.json'...
 
 Found 'package.json' at '/user/username/projects/myproject/packages/pkg1/package.json'.
 ======== Resolving module 'pkg2' from '/user/username/projects/myproject/packages/pkg1/index.ts'. ========
@@ -494,13 +498,7 @@ File '/user/username/projects/myproject/packages/pkg2/build/const.d.cts' exists
 File '/a/lib/package.json' does not exist.
 File '/a/package.json' does not exist.
 File '/package.json' does not exist.
-packages/pkg1/index.ts:1:29 - error TS1479: The current file is a CommonJS module whose imports will produce 'require' calls; however, the referenced file is an ECMAScript module and cannot be imported with 'require'. Consider writing a dynamic 'import("pkg2")' call instead.
-  To convert this file to an ECMAScript module, change its file extension to '.mts' or create a local package.json file with `{ "type": "module" }`.
-
-1 import type { TheNum } from 'pkg2'
-                              ~~~~~~
-
-[12:01:34 AM] Found 1 error. Watching for file changes.
+[12:01:42 AM] Found 0 errors. Watching for file changes.
 
 
 
@@ -521,6 +519,13 @@ Shape signatures in builder refreshed for::
 
 exitCode:: ExitStatus.undefined
 
+//// [/user/username/projects/myproject/packages/pkg1/build/index.js]
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+exports.theNum = void 0;
+exports.theNum = 42;
+
+
 
 Change:: removes those errors when a package file is changed to cjs extensions
 
@@ -535,11 +540,11 @@ export type { TheNum } from './const.cjs';
 
 Output::
 >> Screen clear
-[12:01:42 AM] File change detected. Starting incremental compilation...
+[12:01:50 AM] File change detected. Starting incremental compilation...
 
-[12:01:43 AM] Project 'packages/pkg2/tsconfig.json' is out of date because output 'packages/pkg2/build/tsconfig.tsbuildinfo' is older than input 'packages/pkg2/index.cts'
+[12:01:51 AM] Project 'packages/pkg2/tsconfig.json' is out of date because output 'packages/pkg2/build/tsconfig.tsbuildinfo' is older than input 'packages/pkg2/index.cts'
 
-[12:01:44 AM] Building project '/user/username/projects/myproject/packages/pkg2/tsconfig.json'...
+[12:01:52 AM] Building project '/user/username/projects/myproject/packages/pkg2/tsconfig.json'...
 
 ======== Resolving module './const.cjs' from '/user/username/projects/myproject/packages/pkg2/index.cts'. ========
 Module resolution kind is not specified, using 'Node16'.
@@ -551,9 +556,9 @@ File '/user/username/projects/myproject/packages/pkg2/const.cts' exists - use it
 File '/a/lib/package.json' does not exist.
 File '/a/package.json' does not exist.
 File '/package.json' does not exist.
-[12:01:56 AM] Project 'packages/pkg1/tsconfig.json' is out of date because output 'packages/pkg1/build/index.js' is older than input 'packages/pkg2'
+[12:02:04 AM] Project 'packages/pkg1/tsconfig.json' is out of date because output 'packages/pkg1/build/index.js' is older than input 'packages/pkg2'
 
-[12:01:57 AM] Building project '/user/username/projects/myproject/packages/pkg1/tsconfig.json'...
+[12:02:05 AM] Building project '/user/username/projects/myproject/packages/pkg1/tsconfig.json'...
 
 Found 'package.json' at '/user/username/projects/myproject/packages/pkg1/package.json'.
 ======== Resolving module 'pkg2' from '/user/username/projects/myproject/packages/pkg1/index.ts'. ========
@@ -591,7 +596,7 @@ File '/user/username/projects/myproject/packages/pkg2/build/const.d.cts' exists
 File '/a/lib/package.json' does not exist according to earlier cached lookups.
 File '/a/package.json' does not exist according to earlier cached lookups.
 File '/package.json' does not exist according to earlier cached lookups.
-[12:02:02 AM] Found 0 errors. Watching for file changes.
+[12:02:10 AM] Found 0 errors. Watching for file changes.
 
 
 
@@ -749,13 +754,7 @@ exitCode:: ExitStatus.undefined
   "size": 1064
 }
 
-//// [/user/username/projects/myproject/packages/pkg1/build/index.js]
-"use strict";
-Object.defineProperty(exports, "__esModule", { value: true });
-exports.theNum = void 0;
-exports.theNum = 42;
-
-
+//// [/user/username/projects/myproject/packages/pkg1/build/index.js] file written with same contents
 //// [/user/username/projects/myproject/packages/pkg2/build/index.cjs]
 "use strict";
 Object.defineProperty(exports, "__esModule", { value: true });

tests/cases/compiler/importTypeResolvingToESMFromCJS.ts

@@ -0,0 +1,7 @@
+// @module: nodenext
+
+// @Filename: /types.d.mts
+export interface A {}
+
+// @Filename: /main.cts
+type A = import("./types.mjs").A;