ts-node-dev runs into an error: "Cannot find module 'typescript'"

Question

I am trying to set up a basic nest.js app.

main.js is in the src folder. I run this command:

  npx ts-node-dev src/main.ts

I get this error:

Cannot find module 'typescript'
Require stack:
- /home/yilmaz/.npm/_npx/429895/lib/node_modules/ts-node-dev/lib/index.js
- /home/yilmaz/.npm/_npx/429895/lib/node_modules/ts-node-dev/lib/bin.js

I installed typescript globally, close the terminal and restart it. run tsc -v and I get "Version 4.3.5" but the error is not resolved.

This is the tsconfig.json:

{
  "compilerOptions": {
    "module": "commonjs",
    "target": "es2017",
    "experimentalDecorators": true,
    "emitDecoratorMetadata": true
  }
}

After I installed typescript, I recreated this file with tsc --init and enabled

    "experimentalDecorators": true,
    "emitDecoratorMetadata": true

Thacher

maybe you can try npm link typescript? – Hanky

@Thacher Are you using node 12 or 14? i encounter this error on those versions before. The solution of mine is either 1) upgrade to node.js 16 or 2) install and run both ts and ts-node-dev on the fly npx -p typescript -p ts-node-dev ts-node-dev src/main.ts – Victoir

npx -p typescript -p ts-node-dev ts-node-dev src/main.ts worked me, after installing rxjs. – Gladisgladney

Answer 1

I had this problem myself and even tough I didn't clearly understand the main cause, I did the following stuff and it worked out.

So basically I have installed the ts-node-dev package as a dev dependency(npm i --save-dev ts-node-dev), and after that was running into another error regarding rxjs, so I just installed that too as a dependency(npm i rxjs) and after that it worked ts-node-dev as well as npx ts-node-dev

Balkanize