npm install won't install devDependencies - node.js

Question

On windows for some reason when I run npm install it won't install devDependencies. AFAIK it should. If I run npm install --dev devDependencies are installed. I don't understand why npm install doesn't install devDependencies too, but installs only dependencies. What could be the reason? How can I fix it?
Maybe something is wrong with my package.json? It is listed below if it may be helpful:
{
"name": "try-brunch",
"version": "0.1.0",
"private": "true",
"devDependencies": {
"brunch": "^2.0.4",
"cssnano-brunch": "^1.1.5",
"javascript-brunch": "^1.8.0",
"sass-brunch": "^1.9.2",
"uglify-js-brunch": "^1.7.8"
},
"dependencies": {
"jquery": "^2.1.4"
}
}

Answer 1

Check the NPM docs for install
With the --production flag (or when the NODE_ENV environment variable is set to production), npm will not install modules listed in devDependencies."
The --only={prod[uction]|dev[elopment]} argument will cause either only devDependencies or only non-devDependencies to be installed regardless of the NODE_ENV."
Have you tried
npm install --only=dev
If you are worried that your package.json might be incorrect, best thing to do is this. Create a new folder, and run:
npm init --yes
Then:
npm install --save-dev brunch#^2.0.4
npm install --save-dev cssnano-brunch#^1.1.5
npm install --save-dev javascript-brunch#^1.8.0
npm install --save-dev sass-brunch#^1.9.2
npm install --save-dev uglify-js-brunch#^1.7.8
npm install jquery#^2.1.4 --save
And you should be good to go! Otherwise, will keep posting other options.
Check your npm configuration:
npm config list
npm gets its config settings from the command line, environment variables, and npmrc files. So check environment variables, and the npmrc file.
Still failing?
Ok, create a new folder, ideally somewhere else on your filesystem. ie. not in same folder hierarchy. For instance, C:\myNewFolder - the closer to the base C: drive the better.
Then run:
npm init --yes
Now run:
npm install underscore --save
and finally:
npm install mocha --save-dev
Does everything work as expected?
What I am trying to do is understand whether your problem is global, or something local to the previous folder and dependencies.

Answer 2

Check if npm config production value is set to true. If this value is true, it will skip over the dev dependencies.
Run npm config get production
To set it: npm config set -g production false

Answer 3

make sure you don't have env variable NODE_ENV set to 'production'.
If you do, dev dependencies will not be installed without the --dev flag

Answer 4

You can use the short way for installation dependencies only for development as follows:
npm i -D <dependencies-names>

Answer 5

I had a package-lock.json file from an old version of my package.json, I deleted that and then everything installed correctly.

Answer 6

I had a similar problem. npm install --only=dev didn't work, and neither did npm rebuild. Ultimately, I had to delete node_modules and package-lock.json and run npm install again. That fixed it for me.

Answer 7

I have the same issue because I set the NODE_ENV=production while building Docker. Then I add one more npm install --only=dev. Everything works fine. I need the devDependencies for building TypeSciprt modules
RUN npm install
RUN npm install --only=dev

Answer 8

Make sure your package.json is valid...
I had the following error...
npm WARN Invalid name: "blah blah blah"
and that, similarly, caused devDependencies not to be installed.
FYI, changing the package.json "name" to blah-blah-blah fixed it.

Answer 9

As of now you could use:
npm i --also=dev

Answer 10

So the way I got around this was in the command where i would normally run npm install or npm ci, i added NODE_ENV=build, and then NODE_ENV=production after the command, so my entire command came out to:
RUN NODE_ENV=build && npm ci && NODE_ENV=production
So far I haven't had any bad reactions, and my development dependencies which are used for building the application all worked / loaded correctly.
I find this to be a better solution than adding an additional command like npm install --only=dev because it takes less time, and enables me to use the npm ci command, which is faster and specifically designed to be run inside CI tools / build scripts. (See npm-ci documentation for more information on it)

Answer 11

In my case, the problem was that I had the NODE_ENV variable set to production in the same terminal session I ran npm install.
For my build to run properly I was not allowed to change the value of NODE_ENV so I forced npm to install all the dependencies by adding the --production=false flag to it: npm install --production=false as mentioned in the docs.
If you don't need NODE_ENV to be set to production you can simply type export NODE_ENV=development to your terminal to overwrite its value and run npm install again.

Answer 12

Got a similar error after running npm-check-updates -u. Solved it by removing node_modules folder and package-lock.json. After that a new npm install and everything worked.
My exception:
Failed to load parser '#typescript-eslint/parser' declared in
'package.json » eslint-config-react-app#overrides[0]': Cannot find
module '#typescript-eslint/parser'

Answer 13

As #Ale told, we can use npm i -D <some_module_name> or npm i --save-dev <some_module_name> now.
It seems command was changed at some point of node version.
Offical (npm dependencies and devDependencies) says following.
When you add the -D flag, or --save-dev, you are installing it as a development dependency, which adds it to the devDependencies list.