Feature: Expose esm hooks factory to public API

esm.mjs

@@ -3,9 +3,16 @@ import { createRequire } from 'module';
 const require = createRequire(fileURLToPath(import.meta.url));
 
 /** @type {import('./dist/esm')} */
-const esm = require('./dist/esm');
-export const {
-  resolve,
-  getFormat,
-  transformSource,
-} = esm.registerAndCreateEsmHooks();
+const { createEsmHooks } = require('./dist/esm');
+
+/** @type {import('./dist/index')} */
+const { register } = require('./dist/index');
+
+// Automatically performs registration just like `-r ts-node/register`
+const tsNodeInstance = register({
+  experimentalEsmLoader: true,
+});
+
+export const { resolve, getFormat, transformSource } = createEsmHooks(
+  tsNodeInstance
+);

esm/transpile-only.mjs

@@ -3,9 +3,17 @@ import { createRequire } from 'module';
 const require = createRequire(fileURLToPath(import.meta.url));
 
 /** @type {import('../dist/esm')} */
-const esm = require('../dist/esm');
-export const {
-  resolve,
-  getFormat,
-  transformSource,
-} = esm.registerAndCreateEsmHooks({ transpileOnly: true });
+const { createEsmHooks } = require('../dist/esm');
+
+/** @type {import('../dist/index')} */
+const { register } = require('../dist/index');
+
+// Automatically performs registration just like `-r ts-node/register`
+const tsNodeInstance = register({
+  transpileOnly: true,
+  experimentalEsmLoader: true,
+});
+
+export const { resolve, getFormat, transformSource } = createEsmHooks(
+  tsNodeInstance
+);

src/esm.ts

@@ -1,4 +1,4 @@
-import { register, getExtensions, RegisterOptions } from './index';
+import { getExtensions, Service } from './index';
 import {
   parse as parseUrl,
   format as formatUrl,
@@ -15,17 +15,11 @@ const {
 
 // Note: On Windows, URLs look like this: file:///D:/dev/@TypeStrong/ts-node-examples/foo.ts
 
-export function registerAndCreateEsmHooks(opts?: RegisterOptions) {
-  // Automatically performs registration just like `-r ts-node/register`
-  const tsNodeInstance = register({
-    ...opts,
-    experimentalEsmLoader: true,
-  });
-
+export function createEsmHooks(tsNodeService: Service) {
   // Custom implementation that considers additional file extensions and automatically adds file extensions
   const nodeResolveImplementation = createResolve({
-    ...getExtensions(tsNodeInstance.config),
-    preferTsExts: tsNodeInstance.options.preferTsExts,
+    ...getExtensions(tsNodeService.config),
+    preferTsExts: tsNodeService.options.preferTsExts,
   });
 
   return { resolve, getFormat, transformSource };
@@ -98,17 +92,17 @@ export function registerAndCreateEsmHooks(opts?: RegisterOptions) {
     // If file has .ts, .tsx, or .jsx extension, then ask node how it would treat this file if it were .js
     const ext = extname(nativePath);
     let nodeSays: { format: Format };
-    if (ext !== '.js' && !tsNodeInstance.ignored(nativePath)) {
+    if (ext !== '.js' && !tsNodeService.ignored(nativePath)) {
       nodeSays = await defer(formatUrl(pathToFileURL(nativePath + '.js')));
     } else {
       nodeSays = await defer();
     }
     // For files compiled by ts-node that node believes are either CJS or ESM, check if we should override that classification
     if (
-      !tsNodeInstance.ignored(nativePath) &&
+      !tsNodeService.ignored(nativePath) &&
       (nodeSays.format === 'commonjs' || nodeSays.format === 'module')
     ) {
-      const { moduleType } = tsNodeInstance.moduleTypeClassifier.classifyModule(
+      const { moduleType } = tsNodeService.moduleTypeClassifier.classifyModule(
         normalizeSlashes(nativePath)
       );
       if (moduleType === 'cjs') {
@@ -139,11 +133,11 @@ export function registerAndCreateEsmHooks(opts?: RegisterOptions) {
     }
     const nativePath = fileURLToPath(url);
 
-    if (tsNodeInstance.ignored(nativePath)) {
+    if (tsNodeService.ignored(nativePath)) {
       return defer();
     }
 
-    const emittedJs = tsNodeInstance.compile(sourceAsString, nativePath);
+    const emittedJs = tsNodeService.compile(sourceAsString, nativePath);
 
     return { source: emittedJs };
   }

src/index.ts

@@ -1430,3 +1430,8 @@ function getTokenAtPosition(
     return current;
   }
 }
+
+import type { createEsmHooks as createEsmHooksFn } from './esm';
+export const createEsmHooks: typeof createEsmHooksFn = (
+  tsNodeService: Service
+) => require('./esm').createEsmHooks(tsNodeService);