npm && not working to run two tasks - npm

Question

I'm trying to use straight up npm as my build tool.
{
"name": "ang-starter",
"version": "1.0.0",
"description": "",
"main": "index.js",
"jshintConfig": {
"predef": ["angular"]
},
"scripts": {
"autoprefixer": "postcss -u autoprefixer -r src/assets/css/*",
"scss": "node-sass --output-style compressed -o src/assets/css src/assets/sass/main.scss",
"jshint": "jshint src/app/*.js",
"uglify": "uglifyjs src/app/*.js -o src/assets/js/app.min.js",
"serve": "browser-sync start --server --files 'src/assets/css/, src/assets/js/*.js, **/*.html, !node_modules/**/*.html'",
"watch:css": "onchange 'src/assets/sass/*.scss' -- npm run scss",
"watch:js": "onchange 'src/app/**/*.js' -- npm run jshint && npm run uglify",
"watch:all": "npm-run-all -p serve watch:css watch:js watch:images",
"postinstall": "npm run build:all && npm run watch:all"
},
"author": "",
"license": "ISC",
"devDependencies": {
"autoprefixer": "^6.3.7",
"browser-sync": "^2.13.0",
"jshint": "^2.9.2",
"node-sass": "^3.8.0",
"npm-run-all": "^2.3.0",
"onchange": "^2.5.0",
"postcss-cli": "^2.5.2",
"uglify-js": "^2.6.4"
}
}
My folder set up is like.
src
app
controllers
directives
filters
services
assets
css
images
js
sass
templates
index.html
package.json
My problem is with watch:js, I can run jshint and uglify separately and they work but if I run watch:js which uses && to run jshint and then uglify then the uglify doesn't work and it stops at jshint.

Answer 1

Try npm run watch:js instead of npm watch:js.
I had the same issue with npm in angular2. The build-script:
"build": "rimraf dist && webpack --config config/webpack.prod.js --progress --profile --bail"
wouldn't work - but both commands were running standalone. The run solved it for me.