Package.json pasting a package name in bad? - npm

What happens differently when you go into your package.json and paste a package name in and do npm i vs. doing it the real npm i package-name?
package.json:
"dep": 1.0.0
vs
npm i dep --save
We have a build error and learned can bypass it by pasting. I know it isn't kosher but I really want to know why and what consequences that causes?

npm install dep doesn't add the dependency to the package.json file.
You have to add --save or --save-dev to add it to the package.json file.
Besides that, npm install will always serve you the latest build (in most cases the version tagged as latest (see npm docs)), unless you specify a specific version.
If you want your lock file to update, you have to delete the file before running npm install to generate a lock file with the dependency included (for more info check out this GitHub issue)
In conclussion it shouldn't make much of a difference if you manually add the dependency to package.json file and install it with npm install, unless the latest version of your dependency is broken.

Related

Skip a Specific npm Package on Build Definition on ADO

There are some packages that I'd like to skip on build definition. I was wondering if there's any way to skip any specific npm packages on the build definition on ADO?
For example, if I want to ignore the npm package of #microsoft/applicationinsights-common, can I do something like below in the npm
install --ignore #microsoft/applicationinsights-common
There is no possiblity to ignore one specific npm package using npm install.
If you want to skip such npm packages, that are only needed for development, than in package.json move the development specific dependencies to devDependencies and use npm install --production command to install the packages that are defined in dependencies.

What is the correct use of package.lock.json file, when exactly it works

What is the exact use of package.lock.json file? I have read about it but it's confusing.
Let's say I do npm install so that it will create a package.lock.json file, and the next time when I do npm install, will it retain installation of the same packages as it was mentioned in the package.lock.json file?
Let's say I have a package version defined as "^1.0.0" in my package.json file and a new version becomes available in the npm registry. Will it update the package when I do npm install, or will it keep the same as what was there in the package.json?
Is there any easy way to update the package.json file with the exact no of package version without manually updating it one by one? I want to keep maintain the version of the package the same so that next time anybody does npm install, they should get exactly the same package. It's need for a release branch
Actually I need what was the original definition of package.lock.json file but I found inconsistency in its behavior.
I tried using NPM CI but it fails with error node_gyp needs python https://github.com/nodejs/node-gyp/issues/1977
What is the exact use of package.lock.json file?
Ans: The file is used to describe the exact tree that was generated initially, that is the version of the dependency that was used initially to install (NOTE: It will always be modified if package.json or node_modules are modified by npm)
source: https://docs.npmjs.com/configuring-npm/package-lock-json.html
Now coming to your specific questions :
Let's say I do npm install so that it will create a package.lock.json file, and the next time when I do npm install, will it retain installation of the same packages as it was mentioned in the package.lock.json file?
The simple answer here is: Yes
When you do npm install initially, you specify the package name. npm will create node_modules folder and package-lock.json file and the entry of the package with the version that was used to install will be added. next time when you do npm install, without specifying the package it will not update any of your package even with the caret (^) symbol because this time npm will look at the package-lock.json file (as it is present there) and it will install the same version that is specified in the (package-lock.json) file.
Let's say I have a package version defined as "^1.0.0" in my package.json file and a new version becomes available in the npm registry. Will it update the package when I do npm install, or will it keep the same as what was there in the package.json?
As explained in first question, it will not, if the package-lock.json is present in the directory. Updating of the package will only happen if package-lock.json file and node_modules folder are not present in the directory.
Is there any easy way to update the package.json file with the exact no of package version without manually updating it one by one? I want to keep maintain the version of the package the same so that next time anybody does npm install, they should get exactly the same package. It's need for a release branch
It is a good practice to use npm ci, but you can also use npm update, this will update the dependencies to its latest minor version, and your package.json as well as package-lock.json file will also be updated
For the production, its preferred way to use the same version of dependencies that was used initially. In this case it is better to have package-lock.json file, so in case of dockerizing application when you do npm install it will install the dependencies with versions that are used in package-lock.json

What is the difference between "npm install" and "npm ci"?

I'm working with continuous integration and discovered the npm ci command.
I can't figure what the advantages are of using this command for my workflow.
Is it faster? Does it make the test harder, okay, and after?
From the official documentation for npm ci:
In short, the main differences between using npm install and npm ci are:
The project must have an existing package-lock.json or npm-shrinkwrap.json.
If dependencies in the package lock do not match those in package.json, npm ci will exit with an error, instead of updating the package lock.
npm ci can only install entire projects at a time: individual dependencies cannot be added with this command.
If a node_modules is already present, it will be automatically removed before npm ci begins its install.
It will never write to package.json or any of the package-locks: installs are essentially frozen.
Essentially,
npm install reads package.json to create a list of dependencies and uses package-lock.json to inform which versions of these dependencies to install. If a dependency is not in package-lock.json it will be added by npm install.
npm ci (also known as Clean Install) is meant to be used in automated environments — such as test platforms, continuous integration, and deployment — or, any situation where you want to make sure you're doing a clean install of your dependencies.
It installs dependencies directly from package-lock.json and uses package.json only to validate that there are no mismatched versions. If any dependencies are missing or have incompatible versions, it will throw an error.
Use npm install to add new dependencies, and to update dependencies on a project. Usually, you would use it during development after pulling changes that update the list of dependencies but it may be a good idea to use npm ci in this case.
Use npm ci if you need a deterministic, repeatable build. For example during continuous integration, automated jobs, etc. and when installing dependencies for the first time, instead of npm install.
npm install
Installs a package and all its dependencies.
Dependencies are driven by npm-shrinkwrap.json and package-lock.json (in that order).
without arguments: installs dependencies of a local module.
Can install global packages.
Will install any missing dependencies in node_modules.
It may write to package.json or package-lock.json.
When used with an argument (npm i packagename) it may write to package.json to add or update the dependency.
when used without arguments, (npm i) it may write to package-lock.json to lock down the version of some dependencies if they are not already in this file.
npm ci
Requires at least npm v5.7.1.
Requires package-lock.json or npm-shrinkwrap.json to be present.
Throws an error if dependencies from these two files don't match package.json.
Removes node_modules and install all dependencies at once.
It never writes to package.json or package-lock.json.
Algorithm
While npm ci generates the entire dependency tree from package-lock.json or npm-shrinkwrap.json, npm install updates the contents of node_modules using the following algorithm (source):
load the existing node_modules tree from disk
clone the tree
fetch the package.json and assorted metadata and add it to the clone
walk the clone and add any missing dependencies
dependencies will be added as close to the top as is possible
without breaking any other modules
compare the original tree with the cloned tree and make a list of
actions to take to convert one to the other
execute all of the actions, deepest first
kinds of actions are install, update, remove and move
npm ci will delete any existing node_modules folder and relies on the package-lock.json file to install the specific version of each package. It is significantly faster than npm install because it skips some features. Its clean state install is great for ci/cd pipelines and docker builds! You also use it to install everything all at once and not specific packages.
While everyone else has answered the technical differences none explain in what situations to use both.
You should use them in different situations.
npm install is great for development and in the CI when you want to cache the node_modules directory.
When to use this? You can do this if you are making a package for other people to use (you do NOT include node_modules in such a release). Regarding the caching, be careful, if you plan to support different versions of Node.js remember that node_modules might have to be reinstalled due to differences between the Node.js runtime requirements. If you wish to stick to one version, stick to the latest LTS.
npm ci should be used when you are to test and release a production application (a final product, not to be used by other packages) since it is important that you have the installation be as deterministic as possible, this install will take longer but will ultimately make your application more reliable (you do include node_modules in such a release). Stick with LTS version of Node.js.
npm i and npm ci both utilize the npm cache if it exists, this cache lives normally at ~/.npm.
Also, npm ci respects the package-lock.json file. Unlike npm install, which rewrites the file and always installs new versions.
Bonus: You could mix them depending on how complex you want to make it. On feature branches in git you could cache the node_modules to increase your teams productivity and on the merge request and master branches rely on npm ci for a deterministic outcome.
The documentation you linked had the summary:
In short, the main differences between using npm install and npm ci are:
The project must have an existing package-lock.json or npm-shrinkwrap.json.
If dependencies in the package lock do not match those in package.json, npm ci will exit with an error, instead of updating the package lock.
npm ci can only install entire projects at a time: individual dependencies cannot be added with this command.
If a node_modules is already present, it will be automatically removed before npm ci begins its install.
It will never write to package.json or any of the package-locks: installs are essentially frozen.
The commands are very similar in functionality however the difference is in the approach taken to install the dependencies specified in your package.json and package-lock.json files.
npm ci performs a clean install of all the dependencies of your app whereas npm install may skip some installations if they already exist on the system. A problem may arise if the version already installed on the system isn't the one your package.json intended to install i.e. the installed version is different from the 'required' version.
Other differences would be that npm ci never touches your package*.json files. It will stop installation and show an error if the dependency versions do not match in the package.json and package-lock.json files.
You can read a much better explanation from the official docs here.
Additionally, you may want to read about package locks here.
It is worth having in mind that light node docker images like alpine do not have Python installed which is a dependency of node-gyp which is used by npm ci.
I think it's a bit opinionated that in order to have npm ci working you need to install Python as dependency in your build.
More info here Docker and npm - gyp ERR! not ok
npm ci - install exactly what is listed in package-lock.json
npm install - without changing any versions in package.json, use package.json to create/update package-lock.json, then install exactly what is listed in package-lock.json
npm update - update package.json packages to latest versions, then use package.json to create/update package-lock.json, then install exactly what is listed in package-lock.json
Or said a different way, npm ci changes 0 package files, npm install changes 1 package file, and npm update changes 2 package files.
It does a clean install, use it in situations where you would delete node_modules and re-run npm i.
I have no idea why some people think it's short for "continuous integration". There is an npm install command that can be run as npm i and an npm clean-install command that can be run as npm ci.
npm install is the command used to install the dependencies listed in a project's package.json file, while npm ci is a command that installs dependencies from a package-lock.json or npm-shrinkwrap.json file. The npm ci command is typically used in continuous integration (CI) environments, where the package-lock.json or npm-shrinkwrap.json file is checked into version control and should not be modified. Because npm ci installs dependencies from a locked file, it is a faster and more reliable way to install dependencies than npm install, which could install different versions of dependencies based on the state of the package.json file.

How do I force npm to reinstall a single package, even if the version number is the same?

In my Node.js project, I have a dependency on another local project. Oftentimes, I need to make a small change to the dependency and see how it affects my main project. In order to do this, I have to reinstall my dependency using npm.
I can use npm update to try to update my dependency, but this seems like it will only work if the version number has changed on the dependency. I don't want to have to change the version number on my dependency every time I change a line of code or two to make an experimental change in development.
I can rm -rf node_modules/; npm install to ensure that I get the latest versions of all of my dependencies. Downloading all of my non-local dependencies takes several minutes, breaking up my train of thought.
Is there a way to force npm to reinstall a single dependency, even if that dependency's version number hasn't changed?
When you run npm install, it will install any missing dependencies, so you can combine it with an uninstall like this:
npm uninstall some_module; npm install
With npm 5, uninstalled modules are removed from the package.json, so you should use:
npm uninstall some_module; npm install some_module
On npm v 6.14:
npm install module_name --force --no-save
You get a message stating:
npm WARN using --force I sure hope you know what you are doing.
And then it proceeds to uninstall and reinstall the package.
Note: if you don't specify the --no-save option, npm updates the package version on package.json to the highest version that is compatible with the existing SemVer rule.
If you do not want npm to update the package's version on package.json, keep the --no-save option.
Not the best answer, but just for information, you can run
npm ci
It is the same as npm install, but it will remove the existing node_modules folder, if any, and do a fresh install for all packages. This is useful if the files in node_modules have been changed for some reason and you want to revert them to their original state.

npm install only if package missing or out-of-date compared to package.json

I want to be able to compare my locally installed packages against my project package.json file without making a call against the npm online repo. If there is a package that is out of date based on the package.json file, then and only then will it go to the npm online repo and install the package.
The reason for this is that I want to be able to update the package.json file to require a newer version of a package, commit this change to the project repo and when other developers on the team get latest their npm package is updated. I do not want to slow down the process if everything is up-to-date or cause the build to fail if access to the npm repo or the internet is down.
I am wondering if this is an already solved use-case or do I need to parse the package.json file and compare it to a "npm ls" output myself?
you will need to setup a local repository (by duplicating the NPM couchdb localy)
( see https://stackoverflow.com/a/7577265/406458)
then you could use npm-check-updates.
npm-check-updates will give you a list of packages that can be updated in your package.json file see
https://www.npmjs.org/package/npm-check-updates
$ npm-check-updates
"connect" can be updated from 2.8.x to 2.11.x (Installed: 2.8.8,
Latest: 2.11.0) "commander" can be updated from 1.3.x to 2.0.x
(Installed: 1.3.2, Latest: 2.0.0)
Run 'npm-check-updates -u' to upgrade your package.json automatically
Check global npm packages for updates:
$ npm-check-updates -u