Control Operators

· 144 words · 1 minute read

I want to share with you a couple of operators I find really useful when creating npm scripts.

The & and && operators let you define multiple tasks in one npm script. For example,

  "scripts": {
    "start": "cd theme/cactus && git submodule pull"

In the code above, the second command git submodule pull after the first command cd theme/cactus is executed and finished.

Following a similar sample,

  "scripts": {
    "build": "npm run build:web & npm run build:admin"
    "build:web": "...."
    "build:admin": "..."

When using the operator &, it will run the first command in the background, returning immediately a success signal always, so the second command runs always and, more or less, at the same time as the first one.

In short, use & for parallel executions and && for sequential executions.

UPDATE: Check the new post for a better solution Concurrent Scripts