Cannot find module 'typescript'

[s97712]

when I execute: $ npx ts-node, it throwing
Cannot find module 'typescript'
how should I fix that?

tsconfig.json

{
  "compilerOptions": {
    "module": "commonjs",
    "target": "es2017",
    "noImplicitAny": true,
    "moduleResolution": "node",
    "sourceMap": true,
    "preserveConstEnums": true,
    "outDir": "dist"
  },
  "include": [
    "src/**/*"
  ]
}

src/index.ts

console.log("test");

package.json

{
  "name": "agent",
  "version": "1.0.0",
  "main": "index.js",
  "license": "MIT",
  "scripts": {
    "start": "tsc && node dist/index.js",
    "dev": "nodemon --watch 'src/**/*.ts' -e ts,tsx --exec 'ts-node' ./src/index.ts",
    "debug": "nodemon --inspect --watch 'src/**/*' -e ts,tsx --exec 'ts-node' ./src/index.ts"
  },
  "dependencies": {
    "@types/koa-router": "^7.0.32",
    "koa": "^2.5.3",
    "koa-router": "^7.4.0",
    "nodemon": "^1.18.4",
    "pg": "^7.5.0"
  },
  "devDependencies": {
    "@types/koa": "^2.0.46",
    "@types/pg": "^7.4.11",
    "ts-node": "^7.0.1"
  }
}

[s97712]

I try to run npx ts-node -e 'console.log("test")', it still throwing
Cannot find module 'typescript'

[blakeembrey]

TypeScript is required if you want to compile using ts-node.

[mbujold]

I have this issue with typescript installed globally.

Here is the error:

Error: Cannot find module 'typescript'
at Function.Module._resolveFilename (internal/modules/cjs/loader.js:580:15)
at Function.resolve (internal/modules/cjs/helpers.js:30:19)
at Object.register (C:\Users\marcb\AppData\Roaming\npm\node_modules\ts-node\src\index.ts:208:28)
at Object. (C:\Users\marcb\AppData\Roaming\npm\node_modules\ts-node\src\bin.ts:108:17)
at Module._compile (internal/modules/cjs/loader.js:688:30)
at Object.Module._extensions..js (internal/modules/cjs/loader.js:699:10)
at Module.load (internal/modules/cjs/loader.js:598:32)
at tryModuleLoad (internal/modules/cjs/loader.js:537:12)
at Function.Module._load (internal/modules/cjs/loader.js:529:3)
at Function.Module.runMain (internal/modules/cjs/loader.js:741:12)
npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! vipor-rest@0.1.0 dev: ts-node ./src/server.ts
npm ERR! Exit status 1
npm ERR!
npm ERR! Failed at the vipor-rest@0.1.0 dev script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.

npm ERR! A complete log of this run can be found in:
npm ERR! C:\Users\marcb\AppData\Roaming\npm-cache_logs\2019-01-23T10_03_59_349Z-debug.log

Happens with the following packages:
ts-node@8.0.1
typescript@3.2.4

[s97712]

ts-node need installed globally too. or both installed locally

[hwanpenn]

same problem

[dance2die]

Same issue (not sure if it's due to NVM though).

[blakeembrey]

You'll need to install typescript locally since v8, it's using require.resolve which has its own separate limitations but is used to resolve a different issue. That means typescript is resolved from where you're running it right now.

[adueck]

@blakeembrey It would be really nice to be able to run this with typescript installed globally. I would love to be able to quickly run .ts files in node without having to init a project, install typescript again etc.

[blakeembrey]

@adueck It makes sense, but isn't going to happen in 8.0 right now. I could put it behind a flag though. See reasoning in #697.

[blakeembrey]

@Redfish52 There's a 👍 button if you just want to chime in and aren't contributing to the issue.

For anyone else, I'd like to know if a flag is adequate enough for now.

[ORESoftware]

@blakeembrey putting it behind a flag would be just fine for me, sounds good. Question of course is what should the flag be called, shall we bikeshed? :) how about --use-global-version or --ugv for short. I am sure someone can think of something better.

[codler]

Why do it need to be behind a flag? Cant you just do a fallback if typescript isn't installed locally, search for globally?

[blakeembrey]

@codler That creates an inconsistent environment for people, e.g. a dev environment may have it installed locally and another person not installed locally. This can create simple misunderstandings and more issues.

[codler]

Hm, locally is bound to a project in package.json, and when its bound to project I cant see how the other person wouldn't have it locally also without installed the project wrongly.

[blakeembrey]

What about if you never did npm install? That'll use both the global ts-node and globally typescript automatically. What about if someone else didn't add it in the package.json? Right now, I'm against trying to automatically resolve via two different paths and not sure what value it'd really add.

[vadim-96]

As a temporary solution I used these settings:
"code-runner.executorMap": { "typescript": "tsc $fileName && node $fileNameWithoutExt" }

[blakeembrey]

@Redfish52 I'm not sure what that's working around, but npm install typescript is the "fix" here.

[jajaperson]

Any progress on the flag?

[jajaperson]

What if you defaulted to using the global typescript module when ts-node is installed globally?

[blakeembrey]

@jajaperson #707 (comment). You can always submit a PR too, it's a relatively small change.

[Deamon87]

I have stumbled across this same issue just now.

    "ts-loader": "^6.0.3",
    "ts-node": "^8.3.0",

In ts file:

import ts from 'typescript';

tsconfig:

{
  "compilerOptions": {
    "outDir": "./dist/",
    "sourceMap": true,
    "noImplicitAny": true,
    "module": "ES6",
    "target": "es6",
    "jsx": "react"
  }
}

If I change module to

"module": "commonjs"

it is able to find typescript. But with "ES6" option it magically loses this ability

error TS2307: Cannot find module 'typescript'.

[hamad-Adel]

I solve this problem by reinstalling typescript globally
npm i -g typescript

[basickarl]

I had to do a reinstall of my local node modules then it worked.

[haixiangyan]

I tried to reinstall the typescript globally, and it works!
Try:

yarn global add typescript

or

npm i -g typescript

Try one way, and if it still don't work, then try the other way.

[byteab]

yarn add -D typescript

[KarmaBlackshaw]

This did the trick for me.

For me just running the below command is not enough (though a valid first step):

npm install -g typescript

The following command is what you need (I think deleting node_modules works too but the below command is quicker).

npm link typescript

[matinhu]

This did the trick for me.

For me just running the below command is not enough (though a valid first step):

npm install -g typescript

The following command is what you need (I think deleting node_modules works too but the below command is quicker).

npm link typescript

i have no idea why this occurred, but the command npm link typescript saved my day;
thank you!

[cspotcode]

You should also be able to do a normal `npm install typescript`. Typically, folks in the npm ecosystem will recommend installing dependencies locally per-project, tracking version numbers in package.json. (that's what the above command does) This allows projects to function in isolation without potentially being broken by a different globally-installed version number. `npm link typescript` creates a symlink from your local project pointing at the globally-installed version of typescript. So it's as if your globally installed typescript was also installed locally. `npm install typescript`, on the other hand, will install locally and track the version number in your `package.json`. This means others can quickly `npm install` and automatically get the same local environment as you, which simplifies on-boarding and makes everything more predictable and obvious.

…

On Tue, Jul 7, 2020, 4:30 PM MatinhoGlobal ***@***.***> wrote: This <https://stackoverflow.com/questions/44611526/how-to-fix-cannot-find-module-typescript-in-angular-4> did the trick for me. For me just running the below command is not enough (though a valid first step): npm install -g typescript The following command is what you need (I think deleting node_modules works too but the below command is quicker). npm link typescript i have no idea why this occurred, but the command npm link typescript saved my day; thank you! — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#707 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAC35OEZK3YLA4HYER6SDNDR2OAXZANCNFSM4F3H4SSA> .

[Jood80]

I fixed mine by typing
npm i -D @types/node typescript ts-node

[Wandersonelias]

@Jood80 thanks also fixed my error
npm i -D @types/node typescript ts-node

[installH]

直接进入blinker-js目录，然后运行 npm install typescript 就能解决问了！

[poobah-fruitful]

I fixed mine by typing
npm i -D @types/node typescript ts-node

this worked for me as well ,thank you!

[mildmojo]

Once in a while, I'm in a stripped-down environment where I'd like to run ts-node via npx without permanently installing anything (e.g. kubectl exec -it prod-api /bin/sh). Since typescript isn't a dependency, the temporary package downloaded by npx ts-node throws this error.

You can get around this by telling npx to also download a temporary copy of typescript:

npx -p typescript -p ts-node ts-node

(tested with npx v6.14.8)

[cspotcode]

The new npm installs peer dependencies automatically. Does that mean the new npx also auto-installs it? I haven't tested this but I've been wondering if this new auto-install behavior is good or bad for ts-node. It sounds like in your case it's a good thing.

…

On Fri, May 7, 2021, 1:22 PM Tim ***@***.***> wrote: Once in a while, I'm in a stripped-down environment where I'd like to run ts-node via npx without permanently installing <https://nodejs.dev/learn/the-npx-nodejs-package-runner#installation-less-command-execution> anything (e.g. kubectl exec -it prod-api /bin/sh). Since typescript isn't a dependency, the temporary package downloaded by npx ts-node throws this error. You can get around this by telling npx to also download a temporary copy of typescript: npx -p typescript -p ts-node ts-node (tested with npx v6.14.8) — You are receiving this because you commented. Reply to this email directly, view it on GitHub <#707 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAC35OBET2JS3Z7JAEL6DB3TMQOTRANCNFSM4F3H4SSA> .

[mildmojo]

@cspotcode Ah, yep, updating to npm v7.12.0, I see npx is deprecated in favor of a stripped-down version invoked with npm x. It now interactively prompts about downloading packages, suppressed with -y, so this gets me a REPL without errors in the new npm:

npm x -y ts-node

[cspotcode]

@mildmojo Thanks, this is good to know and I'm sure will help other people as well..  I added it to the discussion forum to make it easy to find.  #1305

[rosnk]

had "ts-node" and "typescript" installed globally. was still showing error.

i was missing tsconfig.json file.... which you can generate by running

tsc --init