Debugging TypeScript with ts-node in VSCode

These launch configs will allow you to debug typescript files directly from VSCode. It will honor the tsconfig and resolve node modules properly. You do not need to install ts-node or nodemon, as everything is run using npx. The first

Launch Config

{
  "configurations": [
    {
      "type": "node",
      "request": "launch",
      "name": "ts-node - current file",
      "runtimeExecutable": "npx",
      "runtimeArgs": ["-y", "ts-node"],
      "program": "${file}",
      "cwd": "${fileDirname}",
      "console": "integratedTerminal",
      "internalConsoleOptions": "neverOpen"
    },
    {
      "type": "node",
      "request": "launch",
      "name": "ts-node - watch current file",
      "runtimeExecutable": "npx",
      "runtimeArgs": [
        "-y",
        "nodemon",
        "-q",
        "--exec",
        "npx",
        "-y",
        "ts-node"
      ],
      "program": "${file}",
      "cwd": "${fileDirname}",
      "restart": true,
      "console": "integratedTerminal",
      "internalConsoleOptions": "neverOpen"
    },
  ],
}

Explanation

The first one is pretty straightforward. If the file is src/path/to/example.ts, this is the equivalent of:

cd src/path/to
npx -y ts-node example.ts

It's better to use cwd in this way, as this allows for nested tsconfig files as may appear in a monorepo.

The second one had to be a bit sneaky because of quirks in nodemon. They recently added TypeScript support, but internally it simply runs the ts-node command instead of node. However, to avoid the dependency for those using regular JS, they didn't add ts-node to its dependencies, so npx nodemon doesn't supply the dependency. You could avoid this by installing it in the project with npm i -D ts-node, but I wanted these to work without installing anything. This is solved with the --exec option by compounding npx scripts. The second config is equivalent to:

cd src/path/to
npx -y nodemon -q --exec 'npx -y ts-node' ./example.ts