Cannot find module 'ts-node/register'

Question

I want to use mocha to test my TypeScript/Angular2 project. I tried to use ts-node as described here:

npm install -g ts-node

<

Answer 1

I know this is kind of old, but I ran into this too and wanted to offer the solution I'm currently using.

I installed ts-node globally using sudo npm i -g ts-node. To make this work with mocha, I just had to give mocha the absolute path to the module, like this:

mocha -r /usr/lib/node_modules/ts-node/register test/*Test.ts

Hope that helps someone else.

Answer 2

Try this command instead:

mocha --compilers ts:ts-node/register,tsx:ts-node/register

which works for me.

Answer 3

Error:
module.js:328
    throw err; 
Error: Cannot find module 'ts-node'

Solution: Following command solves the issue.

<b>npm install ts-node --save-dev</b>

(Installs ts-node as a development dependency for your project)

Answer 4

I have mocha and ts-node installed as dev dependencies in my package. I'm also using pnpm. I originally had a script for test that was defined as:

pnpx mocha -r ts-node/register '*.test.ts'

When this stopped working with the same error as reported in this question I fixed it by making the -r path explicit:

pnpx mocha -r ./node_modules/ts-node/register '*.test.ts'

I'm still confused as to why the original version stopped working.

Answer 5

Wow, a silly mistake can cost you time. I was facing the same issue when I was trying to debug my nodejs application. The mistake I had done was that I have created my .vscode folder outside of my nodejs app folder(the directory which had node_modules in it). When I moved my .vscode to that folder, everything work fine. Below is my launch.json file.

{
    "version": "0.2.0",
    "configurations": [
        {
            "type": "node",
            "request": "launch",
            "name": "index",         
            "args": [
                "src/index.ts"
            ],
            "runtimeArgs": [
                "-r",
                "ts-node/register"
            ],
            "cwd": "${workspaceFolder}",
            "protocol": "inspector",
            "internalConsoleOptions": "openOnSessionStart"           
        }
    ],
    "compounds": []
}

Answer 6

Assuming you rather not install ts-node locally and would prefer to use the globally installed node_module. The following examples show what to do for Windows and assumes you're using NVM. If not using NVM, replace NVM_SYMLINK with C:\Program Files\nodejs

Example for command line:

node -r "%NVM_SYMLINK%\node_modules\ts-node\register" script.ts arg1 arg2

Example for bash:

node -r "$NVM_SYMLINK/node_modules/ts-node/register" script.ts arg1 arg2

Example for vscode launch.config

  "configurations": [
    {
      "name": "utils/roll_browser",
      "type": "node",
      "request": "launch",
      "runtimeArgs": [
        "-r",
        /* Slower startup. Runs full typescript validation */
        // "${env:NVM_SYMLINK}/node_modules/ts-node/register"
        /* Faster startup. Doesn't check types or verify the code is valid */
        "${env:NVM_SYMLINK}/node_modules/ts-node/register/transpile-only"
      ],
      "args": ["${workspaceFolder}/utils/roll_browser.ts", "chromium", "756141"],
    },
  ]