run scripts from package.json when files change


Run scripts from package.json when files change.

Install it:

npm install npm-watch

Add a top-level "watch" config to your package.json and a "watch" script to your "scripts":

  "watch": {
    "test": "{src,test}/*.js"
  "scripts": {
    "test": "tape test/*.js",
    "watch": "npm-watch"

The keys of the "watch" config should match the names of your "scripts", and the values should be a glob pattern or array of glob patterns to watch.

Start the watcher with npm run watch in a terminal, then edit some files:

mkdir src test
npm run watch &
cat <<EOF > test/test-sum.js
var test = require('tape')
test('sum module', function (t) {
  var sum = require('../src/sum.js')
  t.ok(sum(1, 2), 3, "Sums appear correct")

(Feel free to use the editor of your choice, cat just makes for easy demos)

You should see that your tests ran automatically, and failed because src/sum.js is missing. Let's fix that:

cat <<EOF > src/sum.js
module.exports = function (a, b)  {
  return 1

Our tests will run again, and this time they almost work. Let's fix sum.js:

cat <<EOF > src/sum.js
module.exports = function (a, b)  {
  return a + b

Tests run perfectly, ship it to the enterprise!

This module does very little but run nodemon for you, all credit for the reliable file watching and process restarting should go to there.