I just run a simple npm install morgan in a folder and for some reason it adds all the sub dependencies to the parent folder. See image attached
Yes, this is a new feature in npm 3.x, you can read about it here:
https://github.com/npm/npm/releases/tag/v3.0.0
Your dependencies will now be installed maximally flat. Insofar as is possible, all of your dependencies, and their dependencies, and THEIR dependencies will be installed in your project's node_modules folder with no nesting. You'll only see modules nested underneath one another when two (or more) modules have conflicting dependencies.
Basically, it now handles dependencies with as little nesting as possible.
Npm has changed the way they organize dependencies. So instead of 2 separate modules requiring the same dependency and installing them in their own node_modules folder. The dependency is only installed once at the same folder level the node module is installed at.
Related
I noticed that npm installs the same node.js packages several times when they are required by different modules.
Is there an option to switch this off and to have one repo for all the packages?
I looked but did not find anything on this...
This is the default behaviour of NPM since version 3. Quoting the changelog of that version:
Your dependencies will now be installed maximally flat. Insofar as is possible, all of your dependencies, and their dependencies, and THEIR dependencies will be installed in your project's node_modules folder with no nesting. You'll only see modules nested underneath one another when two (or more) modules have conflicting dependencies.
As you can see, if you have modules which have conflicting dependencies (i.e. require different versions of the same dependency), multiple versions of such dependencies will be installed, and this cannot be avoided.
If you suspect that your node_modules directory somehow contains duplicates, you can use the command npm dedupe (docs) to find these and reduce the duplication, leaving only one instance of each duplicate.
My node_modules has packages that are not listed in my package.json's dependencies, so I'm guessing that those packages are dependencies of my dependencies. How would I be able to check this? I want to make sure that there aren't any unnecessary packages in my node_modules directory.
If your dependency list won't take too long to reinstall, a simple option is a table-flip: remove the node_modules directory entirely and run npm install to re-create it.
If you don't want to do that, you can try tools that inspect your dependencies, like depcheck as #sagar-gopale suggests in their answer.
Related: Run npm -v to find out if you are running npm v2 or v3. Like #cartant says in their answer, with v3, your node_modules directory will be maximally flat, which means things that used to appear as subdirectories of other modules (when installed with npm v2) will now appear at the top level of node_modules itself. That may be the reason you see more modules than you expect.
If you are using NPM 3, you will likely see a large number of modules that you were not expecting to see in the node_modules directory, as NPM 3 flattens the dependency hierarchy.
Whichever version you are using, if you run the npm list command, NPM should highlight any extraneous modules that are not required.
Please checkout this package.
https://www.npmjs.com/package/depcheck
Since packages can require other packages, just because there are packages in the node_modules folder that don't exist in your packages.json file doesn't mean they aren't needed by one of your specified packages.
If you run an npm prune command on the root directory of your solution it will read the dependency tree and remove the packages that are truly no longer needed.
I've been using ember for a while and when I wanted to install the node dependencies of a project, I just needed to use npm install to create the folder node_modules with all the dependencies (as it's described in http://ember-cli.com/user-guide/).
Since I was using an old version of node I unisntalled node and npm and installed nvm with the versions node v5.0.0 and npm v3.3.6but now, when I try to use npm install to install the dependencies of a project as I used to do before, instead of the dependencies of the package.json file, I get many, many more from things I'm not sure where they come (I think they are dependencies that npm handles by itself in a globally way but now it's adding them to my project locally, but I'm not sure).
Why am I getting all those unknown (for me) dependencies?
Notice that, when I run ember new it generates the correct dependencies in node_modules but if I delete this folder and run npm install happens the same.
That's one of the changes introduced by npm v3.0:
Your dependencies will now be installed flat - by default. If
possible, all of your dependencies, and their dependencies, and their
dependencies will be installed in your project's node_modules folder
without nesting. Nesting will only occur when two or more modules have
conflicting dependencies.
Read more at http://www.felixrieseberg.com/npm-v3-is-out-and-its-a-really-big-deal-for-windows/
I am new to nodejs. And I found that there are many unknown modules in node_modules folder after I installed three modules (express, jade, gulp) in my local project.
Unknown module examples in the node_modules:
vary
statuses
send
promise
From the tutorials I see from others, after they installed gulp, there will be only one "gulp" folder in their node_modules folder, but this is not my case. Why? Thank you.
The node package manager (npm) updated recently, as part of that update, all modules are installed in the top level node_modules folder. This includes modules that your dependencies need to install. In the past these modules would be nested inside another node_modules folder in express (for example).
This is why the tutorials you read say different, likely they were written before this update.
It is mentioned in the npm changelog here
Your dependencies will now be installed maximally flat. Insofar as is
possible, all of your dependencies, and their dependencies, and THEIR
dependencies will be installed in your project's node_modules folder
with no nesting. You'll only see modules nested underneath one another
when two (or more) modules have conflicting dependencies.
#3697 This will hopefully eliminate most cases where windows users ended up with paths that were too long for Explorer and other standard
tools to deal with.
#6912 (#4761 #4037) This also means that your installs will be deduped from the start.
#5827 This deduping even extends to git deps.
#6936 (#5698) Various commands are dedupe aware now. This has some implications for the behavior of other commands:
npm uninstall removes any dependencies of the module that you
specified that aren't required by any other module. Previously, it
would only remove those that happened to be installed under it,
resulting in left over cruft if you'd ever deduped. npm ls now shows
you your dependency tree organized around what requires what, rather
than where those modules are on disk.
#6937 npm dedupe now flattens the tree in addition to deduping. And bundling of dependencies when packing or publishing changes too:
#2442 bundledDependencies no longer requires that you specify deduped sub deps. npm can now see that a dependency is required by something
bundled and automatically include it. To put that another way,
bundledDependencies should ONLY include things that you included in
dependencies, optionalDependencies or devDependencies.
#5437 When bundling a dependency that's both a devDependency and the child of a regular dependency, npm bundles the child dependency. As a
demonstration of our confidence in our own work, npm's own
dependencies are now flattened, deduped, and bundled in the npm#3
style. This means that npm#3 can't be packed or published by npm#2,
which is something to be aware of if you're hacking on npm.
I recently started a new node project and ran npm install *name* --save for both express and nodemon and noticed that 20-30 folders appear in my node_modules folder related to the two packages instead of just express and nodemon. This has never happened when I have run this command with previous projects. Is there any reason why this is happening now?
I expected my node_modules folder to only have "express" and "nodemon"
npm version: 3.3.6
node version: 5.0.0
Stumbled upon your post with a Google Search and thought I'd link the answer :
Your dependencies will now be installed maximally flat. Insofar as is
possible, all of your dependencies, and their dependencies, and THEIR
dependencies will be installed in your project's node_modules folder
with no nesting. You'll only see modules nested underneath one another
when two (or more) modules have conflicting dependencies.
See npm#3's release notes.