`npm build` doesn't run the script named "build" in package.json

Unfortunately npm build is already an internal command, as described in the docs:

This is the plumbing command called by npm link and npm install.It should generally not be called directly.

Because that command already exists, it always shadows over your "build": "node build.js".

The fully-qualified way to run your own script is with run-script or its alias run:

$ npm run build

npm start and others are the short-hand way, but is only an option when an existing npm command doesn't shadow it, like npm build does.

For posterity (as others have mentioned) npm build is used by npm to build native C/C++ Node addons using node-gyp.

The script named as "build" in package.json is not special in any way. The only way to get it to run is to call:

npm run-script build

There are some names which are called automatically by npm, but "build" is not one of them. The full list is:

• prepublish, publish, postpublish
• preinstall, install, postinstall
• preuninstall, uninstall, postuninstall
• preversion, version, postversion
• pretest, test, posttest
• prestop, stop, poststop
• prestart, start, poststart
• prerestart, restart, postrestart
• preCUSTOM and postCUSTOM for custom script names.

OK, to run a build on it's own, use:

npm run-script build