When not to use package-lock.json

Gajus Kuizinas on September 26, 2019

I maintain over 200 repositories on GitHub and one of the most common PRs that I receive is someone adding package-lock.json or yarn.lock. These PR... [Read Full]
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Not again :(

This is incorrect, the lockfiles should always be committed. This isn't about you, but about your external contributors and project archival. The lockfile ensures that we never lose track of the last known good state.

Previous discussion: twitter.com/arcanis/status/1164229...


I did. And working on package managers is part of my daily job, so it's not the first time I think about this.

My thread is a good explanation of the problems in your reasoning, and I'd be happy to go into more details if you have a specific point you'd like to challenge.

I am not advocating against using package-lock.json for programs designed to be consumed by the end consumer. I do suggest not to use lock files in packages that will be dependencies of other packages.

I have read comments of the multiple people who are suggesting to use package-lock.json because it locks down dev dependencies. This is not a valid use case for the same reasons that I outline in the article. If you need to lock down dev dependencies, use semver range that meets your requirements.

If you need to lock down dev dependencies, use semver range that meets your requirements

Exact semver range isn't locking. Transitive dependencies are still free to change unless you use a proper lockfile.

This isn't to say that exact dependencies are useless (some of my codebases use them), but they solve a different problem and it shouldn't impact at all whether the lockfiles are meant to be committed or not.

I am not advocating against using package-lock.json for programs designed to be consumed by the end consumer

This is the part I'm objecting to. To quote myself:

A lockfile isn't meant to prevent breakages [for consumers] - it's to ensure smooth deployments and development cycles. The first isn't super relevant to libraries and tooling, but the second very much is.

I understand your argument (using lock files ensures smooth deployments and development cycles). However, unlike others in this thread, I do not put as much value on this argument compared to the downsides I have described in this article. In practise, I have found it extremely rare that dependencies or transitive dependencies break or introduce bugs within semver changes that prevent me from working or that would have been prevented using lock files. Happened, maybe 3 times over the last 5 years that my work was interrupted for longer than an hour.


The state of dependencies should be described in package.json. That's what the dependencies field is for. Package-lock.json is unnecessary.


Not that this is common, but what about the dependencies that your dependencies rely on? What if they change?


I get it - similar idea expressed in this article yehudakatz.com/2010/12/16/clarifyi.... But from experience npm packages are fragile, what you were able to install today (based on package.json) doesn't guarantee you would be able to install in a month. How do you deal with fragility? I gave up and commit lock files.


You can always use exact version number dependencies in package.json. Package-lock.json is unnecessary.


Your "exact version number dependencies" have other dependencies which most likely are not "exact version number dependencies", so case described by @stereobooster still applies. You will most likely get different packages in time when you use npm install on your project without package-lock file, and your project may break because of that. I agree it's a pain to maintain it but sometimes there is no other way.


The headline is misleading, there are as you already told different use cases.


There is only so much information that can be contained in the title. Do you have suggestions how to rephrase the title?


Thank you for the suggestion. I have updated article title.


If the package-lock.json has a dependency outside a range defined in package.json, the lock file will be updated with the exact version used. Therefore, they always match.

I tried not using a package-lock.json. After the second instance of a dependency's dependency breaking my build, it became obvious that the lock file is there for a reason... I always use it now so everyone gets the exact same versions.


Not everyone adheres to semver. That's where this falls apart.

Most popular package that disregards semver: typescript


I agree that your lockfile must not be packaged and shipped within the library.

However, when developing libraries you probably have a set of development dependencies and/or normal dependencies. Here is where I disagree, because these should actually be in a lockfile (in my opinion). You are still pulling dependencies there, even ones not included in the publishes library.

The alternative of using exact versions is also possible. Although, for me, the tradeoffs of messy commit to update patches and losing the ability of quick updates (remove lockfile/npm update) is a no-go for me.


It doesn't matter if you are developing in a team or solo. The package lock provides a clear vision which version of dependencies and dependencies of dependencies are being used,and sets them to a fixed version. You do not have any control of deeper dependencies without a package lock which can be reviewed. npm i updates dependencies without you noticing, that's why you use a npm ci when you want to rebuild your node modules.

When updating all packages you can create a specific feature and check those changes. Or automate it if you have decent test


Keep pushing, I think this is an important improvement.


I understand that even if you have the package-lock it will have no effect on any npm install ran on you machine, docker or CI/CD. That's why it is always updated after an npm install.

It only makes a difference if you ran npm ci, right?


As far as I know, yes. (Although I'm aware you wanted the author to answer you).

npm ci is has been very useful for consistent development and ci-build environments, for me at least.


This is more of your own opinion Gajus than a best practice.
Mael has pointed out good reasons to use lockfiles.

2 articles I wrote to provide more context on lockfiles are:

  1. snyk.io/blog/making-sense-of-packa...
  2. if you use lockfiles, there's also a potential security issue that you should know about: snyk.io/blog/why-npm-lockfiles-can...

Aren't you mixing up two things here; committing to a source code repository, and publishing to a registry?

npm pack strips out package-lock.json for publishing. But I believe that even if there were package-lock.json files in dependencies, npm install ignores any but the top-level one, anyway. It wouldn't make sense conceptually to consider them, because if you successfully lock down your dependency versions from your root, you implicitly lock them for all dependencies further down the tree, as well.

On the other hand, nothing speaks against publishing package-lock.json with the source code. In fact, that's half of the reasons for its existence. Because it only has an effect if it's the top-level package, it will help library developers with its intended purpose, while not affecting library consumers.

Please correct me if I'm misunderstanding something here!


I'm maintaining PHP packages and we have the same debate about composer.lock in libraries.

I'm lucky to live in the same city as one of the two authors of composer (npm's counterpart in php world) so once I could have a personal discussion about the topic with him.

He also suggested to commit the lock file with the package (which I don't do either) but he also suggested to do this in the CI pipeline:

  • test the package with the deps as in the lockfile
  • downgrade direct deps to the lowest version allowed by .json file and test against that
  • upgrade the direct deps to the highest version allowed by .json file and test against that as well

Here I can see the benefit of the lockfile, albeit I haven't started doing it yet


I think package-lock.json for security purpose.
When a user hit npm install package-lock.json created commit the package-lock.json changes to version control. They must be insecure network.

Once the package-lock.json generated from true (secure) network and your other machine network might under attack and hacker might change npm registry DNS/Route/IP in that case npm will check the integrity with npm install.


I am not using lock file on modules, I am now facing a hard issue accross many projects. Terser is breaking on production build of my documentation, having lock file accross the chain of dependencies would have prevented that.


Instead it's better to set npm with --save-exact (in .npmrc or on every install).


Because package-lock.json cannot be added to NPM registry

This is false.


The solution for the stated problem is not not using lock files. It should be choosing pinned dependencies vs ranges.


I did not understand how not commiting package-lock solves this issue? won't package.json will update sub-dependencies anyway?


"but it was archived without an action."- probably they just act like you, closing PRs without any notice 😅


I do provide explanation to every PR I close.


On the other hand, wouldn't you like to lock versions of devDependencies, leverage faster builds in ci, etc?

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