feat: Added esm loader

Author: nonara

esm.mjs

@@ -0,0 +1,13 @@
+import { fileURLToPath } from 'url';
+import { createRequire } from 'module';
+const require = createRequire(fileURLToPath(import.meta.url));
+
+/** @type {import('./src/compatibility/node-register')} */
+const { nodeRegister } = require('./dist/compatibility/node-register');
+
+/** @type {import('ts-node')} */
+import tsNode from 'ts-node';
+
+const tsNodeInstance = nodeRegister();
+
+export const { resolve, getFormat, transformSource } = tsNode.createEsmHooks(tsNodeInstance);

package.json

@@ -64,7 +64,7 @@
     "rimraf": "^3.0.2",
     "standard-version": "^9.3.1",
     "ts-jest": "^27.0.4",
-    "ts-node": "^10.1.0",
+    "ts-node": "^10.4.0",
     "ts-patch": "^1.4.4",
     "ts3": "npm:typescript@3.7.7",
     "ts45": "npm:typescript@4.5.0-beta",

register.js

@@ -7,5 +7,4 @@ try {
   );
 }
 
-tsNode.register();
 require('./').nodeRegister();

src/compatibility/node-register.ts

@@ -68,7 +68,7 @@ export function mergeTransformers(
 // region: TsNode Registration Utility
 /* ****************************************************************************************************************** */
 
-export function nodeRegister(): TSNode.RegisterOptions | undefined {
+export function nodeRegister(): TSNode.Service | undefined {
   const { tsNodeInstance, tsNode } = nodeRegister.initialize();
 
   const transformerConfig = getProjectTransformerConfig(tsNodeInstance.config);
@@ -96,8 +96,7 @@ export function nodeRegister(): TSNode.RegisterOptions | undefined {
   }
 
   // Re-register with new transformers
-  tsNode.register(registerOptions);
-  return registerOptions;
+  return tsNode.register(registerOptions);
 }
 
 export namespace nodeRegister {

test/projects/esm-loader/package.json

@@ -0,0 +1,6 @@
+{
+  "private": true,
+  "name": "@tests/esm-loader",
+  "version": "0.0.0",
+  "type": "module"
+}

test/projects/esm-loader/src/id.ts

@@ -0,0 +1 @@
+export const b = null;

test/projects/esm-loader/src/index.ts

@@ -0,0 +1,4 @@
+export * from "#identifier";
+import { b } from "#identifier";
+
+console.log(b);

test/projects/esm-loader/tsconfig.json

@@ -0,0 +1,29 @@
+{
+  "include": [ "src" ],
+
+  "compilerOptions": {
+    "noEmit": true,
+
+    "rootDir": ".",
+    "module": "ESNext",
+    "target": "ESNext",
+    "esModuleInterop": true,
+    "moduleResolution": "node",
+    "declaration": true,
+
+    "baseUrl": "./src",
+    "paths": {
+      "#identifier": [ "./id.ts" ]
+    },
+
+    "plugins": [
+      {
+        "transform": "typescript-transform-paths"
+      },
+      {
+        "transform": "typescript-transform-paths",
+        "afterDeclarations": true
+      }
+    ]
+  }
+}

test/tests/compatibility/esm-loader.test.ts

@@ -0,0 +1,22 @@
+import { execSync } from "child_process";
+import path from "path";
+import ts from 'typescript'
+import { projectsPath } from "../../src/config";
+
+/* ****************************************************************************************************************** *
+ * Tests
+ * ****************************************************************************************************************** */
+
+describe(`ESM Loader`, () => {
+  const esmProjectRoot = ts.normalizePath(path.join(projectsPath, "esm-loader"));
+
+  // See: https://github.com/LeDDGroup/typescript-transform-paths/issues/134
+  test(`Transforms ESM project`, () => {
+    const res = execSync(
+      `node --no-warnings --loader tstp/esm --es-module-specifier-resolution=node src/index.ts`,
+      { cwd: esmProjectRoot }
+    ).toString();
+
+    expect(res).toMatch(/^null($|\r?\n)/);
+  });
+});

test/tests/compatibility/node-register.test.ts

@@ -60,6 +60,7 @@ describe(`[Compatibility: ts-node] Register script`, () => {
         registerSpy?.mockRestore();
       }
     });
+
     test(`Uses existing ts-node if found`, () => {
       const fakeInstance: any = {};
 
@@ -172,7 +173,7 @@ describe(`[Compatibility: ts-node] Register script`, () => {
           });
 
           const originalTsNodeInstance = global.process[instanceSymbol];
-          registerResult = nodeRegister()!;
+          registerResult = nodeRegister()!.options;
           instanceRegistrationResult = global.process[instanceSymbol]!;
           global.process[instanceSymbol] = originalTsNodeInstance;