Why does 'yarn install' rewrite package.json?

[rdicroce]

Like the title says: 'yarn install' causes package.json to be rewritten even though there's no reason Yarn needs to modify the file. I'm not sure if this is a bug, per se, but it's definitely surprising behavior. I wouldn't care, except that when Yarn writes package.json, it also sorts dependencies/peerDependencies/etc. So the file content after an install is semantically equivalent, but the raw bytes might be different.

As to why this is bothering me: I'm primarily a Java developer, and I'm accustomed to directly editing the package descriptor (pom.xml for Maven). I'm also accustomed to being able to group related dependencies together (in terms of how they're ordered in the file) and being able to leave comments in the descriptor to explain things, like why a dependency is needed, or why it's not on the latest version. Which you can't do with package.json, and I know I'm not the only person who finds that annoying, because some Googling finds plenty of people proposing various hacky solutions. There was even an issue about it here (#241) that was closed with no action taken because it's a complicated problem.

Well, I invented my own solution (actually the one mentioned in that issue): an automagic transformation between package.json and package.jsonc. JSON is the canonical file, and a JSONC is created from it. Comments can be added in the JSONC, and when it is saved, it gets transformed back to JSON, with the comments being parsed in a separate pass and added to the JSON as a valid JSON object. Similarly, if the JSON changes, it gets transformed to JSONC and the comments are re-inserted at the appropriate places.

It works pretty well, except for that problem of yarn rewriting the file and not preserving the ordering. I've made my magic smart enough that it still knows where the comments are supposed to go, but the re-ordering means I can't group things together.

So: should any of this be considered a bug in Yarn? IMO rewriting package.json for no reason feels like a bug. The sorting behavior also feels unintended, and ideally I'd like for Yarn to preserve the order, but I'd settle for not modifying the file unnecessarily.

[arcanis]

So: should any of this be considered a bug in Yarn? IMO rewriting package.json for no reason feels like a bug. The sorting behavior also feels unintended, and ideally I'd like for Yarn to preserve the order, but I'd settle for not modifying the file unnecessarily.

Not keeping the dependencies in alphabetical order leads to harder-to-maintain projects as you lose the ability to quickly see which dependencies are in use. That they are enforced in a consistent order is intended 🙂

[IgnisDa]

@martinal Were you able to find a solution to this?

[Zhengqbbb]

🙄 Why rewrite package.json.bin and i can't disable the error behavior 👎

[vecerek]

This conflicts with my prettier setup and causes huge issues in my CI where prettier format checks are failing after yarn install. The ability to opt out of this behavior is important. Or at least the ability to configure prettier not to be at odds with yarn's ordering.

[pandeiro]

I'm doing git reset --hard HEAD after the yarn install --immutable step in my CI (which brings new meaning to the word 'immutable'! 😆) in order to work around this 🤷‍♂️

[hanseltime]

@arcanis - is there an issue with providing an opt-in flag for this? (i.e. yarn install --no-format)

That would allow people who have more fine-grained repo toolsets (i.e. biome does these formatting checks, and yarn is just the installer), to opt-in to the functionality that yarn would otherwise provide for the less complex early project starter.

If so, I could potentially put together a PR.