Overwrites pnpm-workspace.yaml into json

[zhm]

I see there was support added for pnpm workspaces, which is awesome. A couple behaviors that were unexpected for me:

• It overwrites pnpm-workspace.yaml and I end up with a pnpm-workspace.yaml that's actually a JSON file. Is this intentional?
• It doesn't seem to respect "named catalogs".

Example, I have this at the bottom of my pnpm-workspace.yaml for an expo/mobile project where I want these dependencies. In package.json I use catalog:mobile, and other projects like the web app I just use catalog:.

catalogs:
  mobile:
    query-string: 7.1.3
    tailwindcss: ^3.4.17

But it upgrades those dependencies anyways. (e.g. upgrades tailwind to v4)

[raineorshine]

Hi, thanks for reporting.

@jakeboone02 Could you look into this please?

[jakeboone02]

Yep, will do.

[jakeboone02]

@raineorshine Before 18.1.0, this library didn't write any YAML files, it only read them. It uses the js-yaml library, which is fine for reading YAML data but is lossy when it comes to formatting and comments. So even if we write the pnpm-workspace.yaml file in proper YAML syntax, it could still make diffs unnecessarily complicated and ugly, plus any comments would be completely removed.

I'm thinking about swapping out js-yaml (which hasn't seen meaningful activity since 2021) for yaml (newest release 1 month ago). This would allow ncu to make minimal changes to the pnpm-workspace.yaml file. This would make for cleaner diffs and avoid loss of information.

Any thoughts or other recommendations before I proceed?

[raineorshine]

npm-check-updates is very careful about only replacing version numbers in package.json, not rewriting the whole file. I didn't think about this for the pnpm-workspace.yaml file, but I think a similar policy would be advisable.

[jakeboone02]

Right, I definitely want to make the fewest changes possible to the file. My question was whether you were ok with me replacing the js-yaml package with yaml. I'll go ahead and do it in my PR to fix this issue and you can review it then.

[raineorshine]

Yes, I'm okay with that.

[raineorshine]

Hi, just wanted to check in on this.

[jakeboone02]

@raineorshine I've been working on this off and on, but could we possibly have a call sometime to work through the logic? I'm struggling a little with determining the right strategy. Probably just need another pair of eyes on it. We can address these, too:

• Does not see catalog inside "workspaces" #1543
• Workspace catalog tests fail on node v24 #1560

[raineorshine]

@fpapado You expressed interest in helping with catalog support. The core implementation is complete, but we have a few other edge cases that we discovered since the release. Would you be available to work with @jakeboone02 on this?

I have other work commitments right now, so I only have limited availability on this community-led feature. I'm happy to answer questions about the codebase though.

[controversial]

It definitely surprised me that npm-check-updates updates rewrites the entire pnpm-workspace.yaml into JSON syntax; preserving exact formatting inside package.json files is one of my favorite features of npm-check-updates

[MKruschke]

Hi @raineorshine
thank you for pointing me to this issue. I can offer to work on it including respecting the .yarnrc.yml.

When I worked on renovate I noticed/used this code which tackles the update of the yml in a very non-invasive way. It also has a great code coverage so I would give it a try to bring it to ncu with an c&p-and-slight-changes approach if you don't have any objection.