Add ESM support

- Add also supertest as example

Author: alexrecuenco

.github/workflows/main.yml

@@ -13,8 +13,9 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
-      - uses: actions/setup-python@v4
+      - uses: actions/setup-python@v5
         with:
+          # python-version: '3.12'
           cache: 'pip'
       - uses: pre-commit/[email protected]
 
@@ -23,7 +24,7 @@ jobs:
 
     strategy:
       matrix:
-        node-version: [18.x, 20.x]
+        node-version: [20.x, 22.x]
 
     steps:
       - uses: actions/checkout@v4
@@ -38,3 +39,5 @@ jobs:
       - run: npm run format
       - run: npm run build:debug
       - run: npm run build:prod
+      - run: npm run check:esmloads
+      - run: npm run check:cjsloads

.npmignore

@@ -0,0 +1,7 @@
+*
+!dist/**
+!src/**
+!package*json
+!README*
+!tsconfig*
+tsconfig.eslint.json

.vscode/settings.json

@@ -7,10 +7,12 @@
     },
     "editor.formatOnSaveMode": "modificationsIfAvailable",
     "[javascript,typescript,jsonc,json]": {
+        "editor.indentSize": "tabSize",
+        "editor.tabSize": 2,
         "editor.defaultFormatter": "esbenp.prettier-vscode",
         "editor.formatOnSaveMode": "modificationsIfAvailable",
     },
-    "eslint.experimental.useFlatConfig": true,
+    "eslint.useFlatConfig": true,
     "jest.jestCommandLine": "npm test -- ",
     "jest.runMode": {
         "type": "on-demand",

__tests__/replace.test.ts

@@ -1,5 +1,5 @@
 import fc, { Arbitrary } from 'fast-check';
-import { replace } from '../src';
+import { replace } from '../src/replacer.js';
 
 const EachSimpleType = [
   ['string', fc.string()],

__tests__/server.test.ts

@@ -0,0 +1,21 @@
+import { serverFactory } from '@/server.js';
+import type { Server } from 'http';
+import request from 'supertest';
+if (process.env.liveUrl) {
+  // eslint-disable-next-line @typescript-eslint/ban-ts-comment
+  //@ts-ignore this enables connection to a live server and verify the app
+  request = request.bind(request, process.env.liveUrl);
+}
+
+let app: Server;
+
+beforeAll(() => {
+  app = serverFactory();
+});
+
+describe('Server responds', () => {
+  // eslint-disable-next-line jest/expect-expect
+  test('Responds 200', async () => {
+    await request(app).get('/health').expect(200);
+  });
+});

__tests__/tsconfig.json

@@ -0,0 +1,22 @@
+// Typescript config for tests
+{
+    "extends": "../tsconfig.json",
+    "compilerOptions": {
+        // "rootDir": "../",
+        "types": ["jest", "node"],
+        "composite": true,
+        "allowJs": true,
+        "sourceMap": true,
+    },
+    "exclude": ["./tsconfig.json"],
+    // "references": [{ "path": "../tsconfig.json" }],
+    "include": [
+        "./**/*",
+        "./**/*",
+        "./*",
+        "../src/**/*",
+        "../jest*.ts",
+        "../tsconfig.aliases.json",
+        "../package.json",
+    ],
+}

eslint.config.mjs

@@ -74,7 +74,7 @@ export default [
         project: [
           './tsconfig.eslint.json',
           './tsconfig.json',
-          './tsconfig.prod.json',
+          './tsconfig.node.json',
         ],
       },
     },

jest.config.ts

@@ -1,15 +1,43 @@
-import type { JestConfigWithTsJest } from 'ts-jest';
+import {
+  createDefaultEsmPreset,
+  pathsToModuleNameMapper,
+  type JestConfigWithTsJest,
+} from 'ts-jest';
+
+import { compilerOptions } from './tsconfig.aliases.json';
+import packageJson from './package.json';
+
+const pathAliases = {
+  ...compilerOptions.paths,
+  // Jest wants to know the folder to do the transformation, not the `src/index.js`. 🤷
+  [packageJson.name]: ['src'],
+};
+
+// See here for more info https://kulshekhar.github.io/ts-jest/docs/getting-started/presets/#advanced
+const preset = createDefaultEsmPreset({
+  tsconfig: './__tests__/tsconfig.json',
+});
 
 const config: JestConfigWithTsJest = {
-  preset: 'ts-jest',
+  ...preset,
+  roots: ['<rootDir>'],
+  modulePaths: [compilerOptions.baseUrl],
+  moduleNameMapper: pathsToModuleNameMapper(pathAliases, {
+    useESM: true,
+  }),
+  modulePathIgnorePatterns: ['<rootDir>/dist/', '<rootDir>/build/'],
   testRegex: [
     '/tests/.*tests?.[jt]sx?',
     '/__tests__/.*tests?.[jt]sx?',
     '.*.(spec|test).[jt]sx?',
   ],
   // I dono't think we need to run the spec multiple times.. the functional test on tests/ maybe.
-  // We can change this if we consider it useful to run the spec tests when the code is transpiled to javascript
-  testPathIgnorePatterns: ['node_modules', 'build/'],
+  // We can change this back if we consider it useful to run the spec tests when the code is transpiled to javascript
+  testPathIgnorePatterns: [
+    'node_modules',
+    '<rootDir>/build/',
+    '<rootDir>/dist/',
+  ],
   testEnvironment: 'node',
   collectCoverageFrom: ['src/**/*.{js,ts,jsx,tsx}'],
   verbose: true,