What is the difference between npm install and npm run build?
I have noticed in my project that sometimes npm starts failing when npm install is performed, but, upon running npm run build, it works just fine.
How does the inner workings of these two targets namely install and run build differ?
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node.js
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npm-install
npm install installs dependencies into the node_modules/ directory, for the node project you're working on. You can call install on another node.js project (module), to install it as a dependency for your project.
npm run build does nothing unless you specify what "build" does in your package.json file. It lets you perform any necessary building/prep tasks for your project, prior to it being used in another project.
npm build is an internal command and is called by link and install commands, according to the documentation for build:
This is the plumbing command called by npm link and npm install.
You will not be calling npm build normally as it is used internally to build native C/C++ Node addons using node-gyp.
npm install installs the depedendencies in your package.json config.npm run build runs the script "build" and created a script which runs your application - let's say server.jsnpm start runs the "start" script which will then be "node server.js"It's difficult to tell exactly what the issue was but basically if you look at your scripts configuration, I would guess that "build" uses some kind of build tool to create your application while "start" assumes the build has been done but then fails if the file is not there.
You are probably using bower or grunt - I seem to remember that a typical grunt application will have defined those scripts as well as a "clean" script to delete the last build.
Build tools tend to create a file in a bin/, dist/, or build/ folder which the start script then calls - e.g. "node build/server.js". When your npm start fails, it is probably because you called npm clean or similar to delete the latest build so your application file is not present causing npm start to fail.
npm build's source code - to touch on the discussion in this question - is in github for you to have a look at if you like. If you run npm build directly and you have a "build" script defined, it will exit with an error asking you to call your build script as npm run-script build so it's not the same as npm run script.
I'm not quite sure what npm build does, but it seems to be related to postinstall and packaging scripts in dependencies. I assume that this might be making sure that any CLI build scripts's or native libraries required by dependencies are built for the specific environment after downloading the package. This will be why link and install call this script.
The main difference is ::
npm install is a npm cli-command which does the predefined thing i.e, as written by Churro, to install dependencies specified inside package.json
npm run command-name or npm run-script command-name ( ex. npm run build ) is also a cli-command predefined to run your custom scripts with the name specified in place of "command-name". So, in this case npm run build is a custom script command with the name "build" and will do anything specified inside it (for instance echo 'hello world' given in below example package.json).
Ponits to note::
One more thing, npm build and npm run build are two different things, npm run build will do custom work written inside package.json
and npm build is a pre-defined script (not available to use directly)
You cannot specify some thing inside custom build script (npm run build) script and expect npm build to do the same. Try following thing to verify in your package.json:
{ "name": "demo", "version": "1.0.0", "description": "", "main": "index.js", "scripts": { "build":"echo 'hello build'" }, "keywords": [], "author": "", "license": "ISC", "devDependencies": {}, "dependencies": {} }
and run npm run build and npm build one by one and you will see the difference. For more about commands kindly follow npm documentation.
Cheers!!
npm build no longer exists. You must call npm run build now. More info below.
npm install: installs dependencies, then calls the install from the package.json scripts field.
npm run build: runs the build field from the package.json scripts field.
https://docs.npmjs.com/misc/scripts
There are many things you can put into the npm package.json scripts field. Check out the documentation link above more above the lifecycle of the scripts - most have pre and post hooks that you can run scripts before/after install, publish, uninstall, test, start, stop, shrinkwrap, version.
npm install is not the same as npm run installnpm install installs package.json dependencies, then runs the package.json scripts.install
npm run install after dependencies are installed.npm run install only runs the package.json scripts.install, it will not install dependencies.npm build used to be a valid command (used to be the same as npm run build) but it no longer is; it is now an internal command. If you run it you'll get: npm WARN build npm build called with no arguments. Did you mean to npm run-script build? You can read more on the documentation: https://docs.npmjs.com/cli/buildThere are still two top level commands that will run scripts, they are:
npm start which is the same as npm run startnpm test ==> npm run testSource: Stackoverflow.com