CODEWITHSUNDEEP
node.jstypescript
guidev
guidev

Reputation: 2865

Typescript/Node Error [ERR_MODULE_NOT_FOUND]: Cannot find module

Converting Project form CJS to ESM

I am attempting to convert my current TypeScript-Node project from ESM to CJS, however, I keep getting the error below

Error [ERR_MODULE_NOT_FOUND]: Cannot find module` 'redacted/dist/config/datadog' 
imported from /redacted/dist/app.js

This is what the import looks like in app.ts:
    import './config/datadog';
And this is what it looks like for app.js
  import './config/datadog';

Here is my datadog.ts document

datadog.ts

import tracer from 'dd-trace';
tracer.init({
    logInjection: true,
    profiling: true,
    appsec: true
});

export default tracer;

Here is the full printout of the error I am recieving when I execute the app via ~/$ node dist/app.js.

> node dist/app.js

node:internal/errors:465
    ErrorCaptureStackTrace(err);
    ^

Error [ERR_MODULE_NOT_FOUND]: Cannot find module 'redacted/dist/config/datadog' imported from /redacted/dist/app.js
    at new NodeError (node:internal/errors:372:5)
    at finalizeResolution (node:internal/modules/esm/resolve:405:11)
    at moduleResolve (node:internal/modules/esm/resolve:966:10)
    at defaultResolve (node:internal/modules/esm/resolve:1176:11)
    at ESMLoader.resolve (node:internal/modules/esm/loader:605:30)
    at ESMLoader.getModuleJob (node:internal/modules/esm/loader:318:18)
    at ModuleWrap.<anonymous> (node:internal/modules/esm/module_job:80:40)
    at link (node:internal/modules/esm/module_job:78:36) {
  code: 'ERR_MODULE_NOT_FOUND'
}

Node.js v18.0.0

Process finished with exit code 1

It works fine When running using ts-node

node --experimental-specifier-resolution=node --loader ts-node/esm app.ts --project tsconfig.json

I have configured my tsconfig.json file like this:
    {
      "compilerOptions": {
        "target": "ES2020",
        "module": "ES2020",
        "lib": ["ES2020"],
        "moduleResolution": "node",
        "esModuleInterop": true,
        "rootDir": "./src",
        "outDir": "./dist",
        "forceConsistentCasingInFileNames": true,
        "strict": true,
      }
    }

Upvotes: 18

Views: 30919

Answers (3)

Bersan
Bersan

Reputation: 3443

From July 2023

I haven't tried updating my typescript to the ts-next version, but this solution worked for me for Typescript v5.1:

Simply add .js to the end of the filename on the import statements, as explained here.

Example:

# Folder structure

app/
  controller/
    mymodule.ts
  index.ts
package.json
tsconfig.json

// package.json
{
  "name": "project-name",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "type": "module", // keep the module keyword
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1",
  ...

// tsconfig.json
{
  "compilerOptions": {
    "target": "ES2020",
    "module": "ES2020",
    "strict": true,
    "esModuleInterop": true,
    "moduleResolution": "node",
    "forceConsistentCasingInFileNames": true,
    "outDir": "./build",
    "rootDir": "./app"
  },
  "exclude": ["node_modules"]
}

// index.ts

import userController from './controller/users.js'
userController.foo();

// mymodule.ts

const foo = async () => {
  await new Promise((resolve, reject) => setTimeout(resolve, 3000));
  return 0;
}

Upvotes: 3

yamumsafookinhoe
yamumsafookinhoe

Reputation: 1

More insight:

Importing './env' only works in CJS.

Importing './env.mjs' is required in ESM.

Relative import paths need explicit file extensions in EcmaScript imports when '--moduleResolution' is 'node16' or 'nodenext'. Did you mean './env.mjs'?ts(2835)

Upvotes: 0

AKUMA no ONI
AKUMA no ONI

Reputation: 11819

Your need to use TypeScript v4.7 which is currently the TS-Next Version

Once you upgrade to typescript@next which can be done by executing the command ~/$ npm install -D typescript@next, you will need to make the changes below to your tsconfig.json file.

  {
    "compilerOptions": {
    "lib": [
      "ESNext" /* ESNext includes new Level-4 features that were
               recently added to the ECMA-262 JS spec */
     ],

    "module": "NodeNext",/* (1 of 2) TS v4.7 settings you need 
                            to change */

    "moduleResolution": "NodeNext", /* This is the one that will 
                                    specifically solve the error you're 
                                    getting. Without the internal changes
                                    made by this, your project will not
                                    resolve modules correctly. */

    "esModuleInterop": true, /* This is properly configured. FYI you cannot 
                                change this, it must be set to true. */
                                

    /* 
      THE REST OF THE SETTINGS DO NOT AFFECT THE MODULE TYPE OR HOW TSC 
      RESOLVES OTHER MODULES */

    "target": "ES2021",
    "rootDir": "./src",
    "outDir": "./dist",
    "forceConsistentCasingInFileNames": true,
    "strict": true,
  }
}

To Summarize

You must set the tsconfig.json keys module and moduleResolution as they are shown below.

  1. `moduleResolution: "NodeNext"
  2. module: "NodeNext"

You will need TypeScript v4.7

Personally I keep a global property, so below I show the command for the global install, but all you really need is to add it to your node_modules dir it as a dependency for your current project.

  1. ~$ sudo npm i -g typescript@next // Global Install

  2. ~$ npm i -D typescript@next // Add as a Project Dependency


I can't help with ever IDE in existance, but if you use VSCode, use the following configuration so your project uses the ver v4.7.

Then you need to set the following configuration

"typescript.tsdk": "./node_modules/typescript/lib",

package.json

You also need to enable ESM in for Node.. To do this you need to add the following to your package.json

/** @file "package.json" */

{
    "type": "module"
}

...OR YOU CAN use the dot MTS (.mts) file extension for all of your files. There are advantages to both, but discussing the advantages is beyond the scope of this answer.

That should be it. It sounds hard but its actually easy once you have done it before.

For another helpful source:

The answer at this LINK covers this same subject with a bit more detail. I really suggest you check it out.

Upvotes: 15

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