check without extensions

lib/internal/modules/esm/resolve.js

@@ -246,8 +246,34 @@ function finalizeResolution(resolved, base, preserveSymlinks) {
  throw err;
  }
 
- const stats = internalFsBinding.internalModuleStat(toNamespacedPath(StringPrototypeEndsWith(path, '/') ?
- StringPrototypeSlice(path, -1) : path));
+ let stats;
+ if (getOptionValue('--experimental-typescript')) {
+ if (StringPrototypeEndsWith(path, '/')) {
+ path = StringPrototypeSlice(path, 0, -1);
+ }
+ // Try to add .ts extension
+ let attemptTsPath = path;
+ if (!StringPrototypeEndsWith(attemptTsPath, '.ts')) {
+ attemptTsPath += '.ts';
+ }
+
+ stats = internalFsBinding.internalModuleStat(toNamespacedPath(attemptTsPath));
+ switch (stats) {
+ case 0:
+ // Found the .ts file
+ path = attemptTsPath;
+ break;
+ case 1:
+ throw new ERR_UNSUPPORTED_DIR_IMPORT(path, fileURLToPath(base), String(resolved));
+ default:
+ // In case we cannot find the .ts file, we fill fall back to js
+ stats = internalFsBinding.internalModuleStat(path);
+ break;
+ }
+ } else {
+ stats = internalFsBinding.internalModuleStat(toNamespacedPath(StringPrototypeEndsWith(path, '/') ?
+ StringPrototypeSlice(path, -1) : path));
+ }
 
  // Check for stats.isDirectory()
  if (stats === 1) {

test/fixtures/typescript/test-import-no-extension.ts

@@ -0,0 +1,2 @@
+import { a } from './a';
+console.log(a);

test/parallel/test-typescript.js

@@ -45,3 +45,17 @@ test('execute a typescript with node_modules', async () => {
  stdout: 'Hello, TypeScript!\n',
  });
 });
+
+test('execute a typescript file with imports with no extensions', async () => {
+ const result = await spawnPromisified(process.execPath, [
+ '--experimental-typescript',
+ fixtures.path('typescript/test-import-no-extension.ts'),
+ ]);
+
+ deepStrictEqual(result, {
+ code: 0,
+ signal: null,
+ stderr: '',
+ stdout: 'Hello, TypeScript!\n',
+ });
+});