A Node + TypeScript + ts-node + ESM experience that works.

node-typescript-esm.md

The experience of using Node.JS with TypeScript, ts-node, and ESM is horrible.

There are countless guides of how to integrate them, but none of them seem to work.

Here's what worked for me.

Just add the following files and run npm run dev. You'll be good to go!

package.json

{
  "private": true,
  "type": "module",
  "exports": "./dist/index.js",
  "types": "./dist/index.d.ts",
  "sideEffects": false,
  "files": [
    "./dist/"
  ],
  "engines": {
    "node": "^20.9.0",
    "npm": "^10.1.0"
  },
  "scripts": {
    "dev": "node --no-warnings --enable-source-maps --loader ts-node/esm src/index.ts",
    "dev:watch": "nodemon --watch src/ -e ts --exec \"npm run dev\"",
    "test": "node --no-warnings --enable-source-maps --loader ts-node/esm --test src/**/*.test.ts",
    "test:watch": "node --no-warnings --enable-source-maps --loader ts-node/esm --test --watch src/**/*.test.ts"
  },
  "dependencies": {},
  "devDependencies": {
    "@sindresorhus/tsconfig": "^5.0.0",
    "nodemon": "^3.0.3",
    "ts-node": "^10.9.1",
    "typescript": "^5.2.2"
  }
}

tsconfig.json

{
  "extends": "@sindresorhus/tsconfig",
  "compilerOptions": {
    "outDir": "./dist/",                              /* Specify an output folder for all emitted files. */
    "lib": ["ES2022"],
    "target": "ES2022",
    "declarationMap": true,                           /* Create sourcemaps for d.ts files. */
    "sourceMap": true,                                /* Create source map files for emitted JavaScript files. */
    "importsNotUsedAsValues": "remove",               /* Specify emit/checking behavior for imports that are only used for types. */    
    "isolatedModules": true,                          /* Ensure that each file can be safely transpiled without relying on other imports. */
    "esModuleInterop": true
  },
  "include": [
    "./src/**/*.ts"
  ],
  "ts-node": {
    "esm": true,
    "transpileOnly": true,
    "files": true,
    "experimentalResolver": true
  }
}

src/utilities/node.ts

Some utilities for getting similar behavior as __filename, __dirname, and require.main === module in Node.JS CommonJS.

This file is optional.

import { fileURLToPath } from 'node:url'
import { dirname } from 'node:path'
import { argv } from 'node:process'
import { createRequire } from 'node:module'

/**
 * This is an ESM replacement for `__filename`.
 * 
 * Use it like this: `__filename(import.meta)`.
 */
export const __filename = (meta: ImportMeta): string => fileURLToPath(meta.url)

/**
 * This is an ESM replacement for `__dirname`.
 * 
 * Use it like this: `__dirname(import.meta)`.
 */
export const __dirname = (meta: ImportMeta): string => dirname(__filename(meta))

/**
 * Indicates that the script was run directly.
 * This is an ESM replacement for `require.main === module`.
 * 
 * Use it like this: `isMain(import.meta)`.
 */
export const isMain = (meta: ImportMeta): boolean => {
  if (!meta || !argv[1]) return false
  const require = createRequire(meta.url)
  const scriptPath = require.resolve(argv[1])
  const modulePath = __filename(meta)
  return scriptPath === modulePath
}

Do we have a fix to resolve this issue?

instead of

"node --no-warnings --enable-source-maps --loader ts-node/esm src/index.ts"

try tsx,

"node --watch --no-warnings --enable-source-maps --import tsx ./src/index.ts"

just wrote about my experience setting up ESM, TypeScript and Node.js v20 here. I ended up using SWC for transpilation, tsc for type-checking and tsx for running TypeScript files

Sure, that --enable-source-maps is needed ? It outputs stacks and debugs fine (with Webstorm) without that flag, just with node --import tsx

Do we have a fix to resolve this issue?

instead of

"node --no-warnings --enable-source-maps --loader ts-node/esm src/index.ts"

try tsx,

"node --watch --no-warnings --enable-source-maps --import tsx ./src/index.ts"

When I try tsx, I can run from the cli, but inside of a Docker container, I get TypeError [Error]: undefined is not iterable (cannot read property Symbol(Symbol.iterator)) at some place in the internals of tsx. Nothing in their github issues that seems to correspond.

Hi, everyone! I hope you're doing well.
I ran the ts file using ts-node but got the error below.

TypeError [ERR_UNKNOWN_FILE_EXTENSION]: Unknown file extension ".ts" for E:\work\test\scan.ts
    at new NodeError (node:internal/errors:406:5)
    at Object.getFileProtocolModuleFormat [as file:] (node:internal/modules/esm/get_format:99:9)
    at defaultGetFormat (node:internal/modules/esm/get_format:142:36)
    at defaultLoad (node:internal/modules/esm/load:120:20)
    at ModuleLoader.load (node:internal/modules/esm/loader:396:13)
    at ModuleLoader.moduleProvider (node:internal/modules/esm/loader:278:56)
    at new ModuleJob (node:internal/modules/esm/module_job:65:26)
    at ModuleLoader.#createModuleJob (node:internal/modules/esm/loader:290:17)
    at ModuleLoader.getJobFromResolveResult (node:internal/modules/esm/loader:248:34)
    at ModuleLoader.getModuleJob (node:internal/modules/esm/loader:229:17) {
  code: 'ERR_UNKNOWN_FILE_EXTENSION'
}

The tsconfig.json file looks like this:

{
    "compilerOptions": {
        /* Visit https://aka.ms/tsconfig.json to read more about this file */
        /* Basic Options */
        // "incremental": true,                   /* Enable incremental compilation */
        "target": "es6" /* Specify ECMAScript target version: 'ES3' (default), 'ES5', 'ES2015', 'ES2016', 'ES2017', 'ES2018', 'ES2019', 'ES2020', or 'ESNEXT'. */,
        "module": "commonjs" /* Specify module code generation: 'none', 'commonjs', 'amd', 'system', 'umd', 'es2015', 'es2020', or 'ESNext'. */,
        // "lib": [],                             /* Specify library files to be included in the compilation. */
        // "allowJs": true,                       /* Allow javascript files to be compiled. */
        // "checkJs": true,                       /* Report errors in .js files. */
        // "jsx": "preserve",                     /* Specify JSX code generation: 'preserve', 'react-native', or 'react'. */
        "declaration": true /* Generates corresponding '.d.ts' file. */,
        // "declarationMap": true,                /* Generates a sourcemap for each corresponding '.d.ts' file. */
        // "sourceMap": true,                     /* Generates corresponding '.map' file. */
        // "outFile": "./",                       /* Concatenate and emit output to single file. */
        "outDir": "lib/" /* Redirect output structure to the directory. */,
        // "rootDir": "./",                       /* Specify the root directory of input files. Use to control the output directory structure with --outDir. */
        // "composite": true,                     /* Enable project compilation */
        // "tsBuildInfoFile": "./",               /* Specify file to store incremental compilation information */
        // "removeComments": true,                /* Do not emit comments to output. */
        // "noEmit": true,                        /* Do not emit outputs. */
        // "importHelpers": true,                 /* Import emit helpers from 'tslib'. */
        // "downlevelIteration": true,            /* Provide full support for iterables in 'for-of', spread, and destructuring when targeting 'ES5' or 'ES3'. */
        // "isolatedModules": true,               /* Transpile each file as a separate module (similar to 'ts.transpileModule'). */
        /* Strict Type-Checking Options */
        "strict": true /* Enable all strict type-checking options. */,
        "noImplicitAny": true /* Raise error on expressions and declarations with an implied 'any' type. */,
        // "strictNullChecks": true,              /* Enable strict null checks. */
        // "strictFunctionTypes": true,           /* Enable strict checking of function types. */
        // "strictBindCallApply": true,           /* Enable strict 'bind', 'call', and 'apply' methods on functions. */
        // "strictPropertyInitialization": true,  /* Enable strict checking of property initialization in classes. */
        // "noImplicitThis": true,                /* Raise error on 'this' expressions with an implied 'any' type. */
        // "alwaysStrict": true,                  /* Parse in strict mode and emit "use strict" for each source file. */
        /* Additional Checks */
        // "noUnusedLocals": true,                /* Report errors on unused locals. */
        // "noUnusedParameters": true,            /* Report errors on unused parameters. */
        // "noImplicitReturns": true,             /* Report error when not all code paths in function return a value. */
        // "noFallthroughCasesInSwitch": true,    /* Report errors for fallthrough cases in switch statement. */
        /* Module Resolution Options */
        "moduleResolution": "node" /* Specify module resolution strategy: 'node' (Node.js) or 'classic' (TypeScript pre-1.6). */,
        // "baseUrl": "./",                       /* Base directory to resolve non-absolute module names. */
        // "paths": {},                           /* A series of entries which re-map imports to lookup locations relative to the 'baseUrl'. */
        // "rootDirs": [],                        /* List of root folders whose combined content represents the structure of the project at runtime. */
        // "typeRoots": [],                       /* List of folders to include type definitions from. */
        // "types": [],                           /* Type declaration files to be included in compilation. */
        // "allowSyntheticDefaultImports": true,  /* Allow default imports from modules with no default export. This does not affect code emit, just typechecking. */
        "esModuleInterop": true /* Enables emit interoperability between CommonJS and ES Modules via creation of namespace objects for all imports. Implies 'allowSyntheticDefaultImports'. */,
        // "preserveSymlinks": true,              /* Do not resolve the real path of symlinks. */
        // "allowUmdGlobalAccess": true,          /* Allow accessing UMD globals from modules. */
        /* Source Map Options */
        // "sourceRoot": "",                      /* Specify the location where debugger should locate TypeScript files instead of source locations. */
        // "mapRoot": "",                         /* Specify the location where debugger should locate map files instead of generated locations. */
        // "inlineSourceMap": true,               /* Emit a single file with source maps instead of having a separate file. */
        // "inlineSources": true,                 /* Emit the source alongside the sourcemaps within a single file; requires '--inlineSourceMap' or '--sourceMap' to be set. */
        /* Experimental Options */
        // "experimentalDecorators": true,        /* Enables experimental support for ES7 decorators. */
        // "emitDecoratorMetadata": true,         /* Enables experimental support for emitting type metadata for decorators. */
        "sourceMap": true,
        /* Advanced Options */
        "lib": [
            "dom",
            "ES2020",
            "ES2021.WeakRef"
        ], 
        "skipLibCheck": true /* Skip type checking of declaration files. */,
        "forceConsistentCasingInFileNames": true /* Disallow inconsistently-cased references to the same file. */
    },
    "exclude": [
        "**/*.d.ts",
        "tools/**/*.ts",
        "scripts/*",
        "demo**/*",
        "tests**/*"
    ]
}

Also this is a package.json file.

{
    "name": "test",
    "version": "1.0.0",
    "type": "module",
    "description": "",
    "main": "index.js",
    "scripts": {
    },
    "keywords": [],
    "author": "",
    "license": "ISC",
    "devDependencies": {
        "@playwright/test": "^1.41.2",
        "@types/node": "^20.11.19",
        "ts-node": "^10.9.2"
    },
    "dependencies": {
        "@types/yargs": "^17.0.32",
        "mime-types": "^2.1.35",
        "playwright-utilities": "^1.0.1",
        "sqlite3": "^5.1.7",
        "yargs": "^17.7.2"
    }
}

I would like to know how to solve this problem. Thank you.

@Rainbow-420 Sorry, i don't think it's the right discussion here for posting some random errors from an ultra long tsconfig that looks like it has nothing to do with that one from the intro comment.

I tried to give you some specifics about the problem I am currently facing.
I'm really sorry if there's too much content and it's confusing.
But I need help with this.

Add tsx and use it instead of node. Enjoy.

Exactly, I was going to say the same: tsx feels much smoother to work with than ts-node