Make @parcel/watcher optional

[valkum]

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Description

This is a new attempt to fix #9320.
@parcel/watcher needs a whole lot of build dependencies on the system. Normally, it will just pull prebuilt binaries for your system. But currently there are no prebuilt binaries for linux on arm64: parcel-bundler/watcher#130
In those environments, it tries to build it from source which means it needs python etc.
This makes @parcel/watcher optional, which should prevent these issues. The user is free to choose if they want to include @parcel/watcher as a dev dependency or take additional measures such as marking it optional (to ignore build errors)

The tests still run and @parcel/watcher should be pulled in via the devDependencies for the tests.
I assumed this would be a breaking change and included a major changeset and a migration guide.

Related #9320

Type of change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

Checklist:

• I have followed the CONTRIBUTING doc and the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules

Further comments

This is the proposed way laid out in the yarn docs. The previous PR just moved @parcel/watcher into optionalDependencies. Yarn says using an optional peer dependency might be better.

[changeset-bot]

🦋 Changeset detected

Latest commit: f105677

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
@graphql-codegen/cli	Major

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[n1ru4l]

Thank you so much for tackling this properly! 🎉
Approved from my side.

[glasser]

In what way is this a breaking change for a user?

[valkum]

As in, previously it was installed as a dependency and for a user to still make use of it, they need to actively add it to their package.json to install it now.

[glasser]

OK — how would I know if my configuration made use of this feature? Is there a particular thing to look for in my config file that would suggest that this is a breaking change for me?

[valkum]

Did your workflow depend on graphql-codegen --watch? If not this is not affecting you. If it was affecting you, you would have seen the following in your terminal:

Failed to import @parcel/watcher due to the following error (to use watch mode, install https://www.npmjs.com/package/@parcel/watcher):

[glasser]

Great — might help to update the release notes to say something explicit like "The graphql-codgen --watch command now requires you to install @parcel/watcher yourself" so that people who don't use that flag don't have to worry about whether the upgrade will break them!

[valkum]

This was merged and released 2 years ago. I guess someone with write access could amend the release notes for https://github.com/dotansimha/graphql-code-generator/releases/tag/release-1690276829878.