How to watch and reload ts-node when TypeScript files change

Question

I\'m trying to run a dev server with TypeScript and an Angular application without transpiling ts files every time. I found that I can do the running with ts-node

Answer 1

This works for me:

nodemon src/index.ts

Apparently thanks to since this pull request: https://github.com/remy/nodemon/pull/1552

Answer 2

i did with

"start": "nodemon --watch 'src/**/*.ts' --ignore 'src/**/*.spec.ts' --exec ts-node src/index.ts"

and yarn start.. ts-node not like 'ts-node'

Answer 3

Another way could be to compile the code first in watch mode with tsc -w and then use nodemon over javascript. This method is similar in speed to ts-node-dev and has the advantage of being more production-like.

 "scripts": {
    "watch": "tsc -w",
    "dev": "nodemon dist/index.js"
  },

Answer 4

I would prefer to not use ts-node and always run from dist folder.

To do that, just setup your package.json with default config:

....
"main": "dist/server.js",
  "scripts": {
    "build": "tsc",
    "prestart": "npm run build",
    "start": "node .",
    "dev": "nodemon"
  },
....

and then add nodemon.json config file:

{
  "watch": ["src"],
  "ext": "ts",
  "ignore": ["src/**/*.spec.ts"],
  "exec": "npm restart"
}

Here, i use "exec": "npm restart"
so all ts file will re-compile to js file and then restart the server.

To run while in dev environment,

npm run dev

Using this setup I will always run from the distributed files and no need for ts-node.

Answer 5

EDIT: Updated for the latest version of nodemon!

I was struggling with the same thing for my development environment until I noticed that nodemon's API allows us to change its default behaviour in order to execute a custom command. For example:

nodemon --watch 'src/**/*.ts' --ignore 'src/**/*.spec.ts' --exec 'ts-node' src/index.ts

Or even better: externalize nodemon's config to a nodemon.json file with the following content, and then just run nodemon, as Sandokan suggested:

{ "watch": ["src/**/*.ts"], "ignore": ["src/**/*.spec.ts"], "exec": "ts-node ./index.ts" }

By virtue of doing this, you'll be able to live-reload a ts-node process without having to worry about the underlying implementation.

Cheers!

Updated for the most recent version of nodemon:

You can run this, for example:

nodemon --watch "src/**" --ext "ts,json" --ignore "src/**/*.spec.ts" --exec "ts-node src/index.ts"

Or create a nodemon.json file with the following content:

{
  "watch": ["src"],
  "ext": "ts,json",
  "ignore": ["src/**/*.spec.ts"],
  "exec": "ts-node ./src/index.ts"      // or "npx ts-node src/index.ts"
}

and then run nodemon with no arguments.