What happen to --ignore-optional?

[bodinsamuel]

There used to be a --ignore-optional with yarn install command.
It was helpful to add optional packages on monorepo, for example storybook or eslint.
Especially when building the final image, you don't really want to install those dependencies as all the checks has already passed.

There is no mention of this command in the migration guide or the rename guide,
I suppose it was discarded because of its "unreliability" however there is no alternative. Installing hundreds of useless packages is a bit painful.

Currently, as far as my knowledges goes, the only way to achieve that previous behavior is to modify the package.json before running yarn install.

Can you recommend a solution and/or add a note about that in the documentation?

Thanks a lot,

[bodinsamuel]

thanks for the move @merceyz, not used to this feature 😬

[arcanis]

It has been removed. It's not so much because of its instability, but rather because noone used it right, and it wasn't very helpful to begin with. Optional dependencies, as defined by the optionalDependencies flag, and that we still support, only have their build optional. The packages are still fetched, and still installed - it's just that if they have built steps, then errors that could happen then are downgraded into warnings. As such, not installing those packages at all would be technically incorrect as it would produce a different execution environment in different cases.

Generally speaking we don't really want to support "partial views" of your project in the core unless we can guarantee the result will make sense. So for instance, we have yarn workspaces focus because we can somewhat guarantee that even if not all the project deps are installed, you'll at least have all those for the workspace you requested. By contrast, we wouldn't have any way to be sure that a install made via --ignore-optional would be correct - so it's place isn't in the core offering.

If you want to reintroduce it, you can do so by either calling yarn remove instead of a classic install, or by implementing a plugin similar to yarn workspaces focus that would automatically do the remove calls in a single operation. I still wouldn't recommend it myself, though.

[bodinsamuel]

Make sense.

I think it would deserve a small mention in the documentation.
And look into the plugin to see if we can implement a similar behaviour 👍🏻

Thanks for the answer

[DeeepDev]

Could you find a clean workaround for ignoring optionalDeps during install? any plugins, or anything else?!

[cellog]

this argument makes sense, but is insufficient for many cases.

For example, we have a much smaller docker image, for which we do not want to install Cypress because it balloons both installation time by 3 minutes and requires us to store an additional 2GB of stuff that is never used. With --ignore-optional, the packages are not installed.

Moving the packages to devDependencies simply fails because the Docker image does not have the prerequisites that Cypress requires to install.

Since the recommended approach is to yarn remove all the optional deps prior to installation, I guess we will have to do that.

I also noticed that install --production is deprecated in favor of workspaces focus -A --production. The --frozen-lockfile flag (or --immutable) is not mentioned, and not supported - can we assume it will fail if the lockfile needs updating?

[fabioDMFerreira]

@arcanis any workaround we can use to remove these optional dependencies? I was able to do it manually but it isn't user friendly.

I am having compiling issues because of having optional dependencies in node_modules that have peer dependencies. If I have this specific optional dependency installed I am forced to install a bunch of dependencies I don't need to make the build process work.

[cmark1302]

looking for same

[DeeepDev]

At least, provide a possibility to ignore specific packages during yarn install, because I myself used optionalDependencies for this purpose also.
In my own case, I have some pipelines that I don't need super heavy packages like cypress there, so it would be very useful to have such feature implemented in the core.

[DeeepDev]

Sounds like pretty logical not to ignore optionalDeps during install, since I found that in my own case, when I ran yarn install --ignore-optional in my merge request pipeline (to ignore cypress from being installed), my jest tests encountered error, since I was using swc and it has its core binaries as optionalDependencies in the package.
Although ignoring cypress install, declined the step time by 75%, I should consider another solution for the issue.

[jamie-pate]

It makes sense to me that we should be able to skip all optional packages. It seems like there are some good use cases to selectively have different execution environments as an optimization which can be e.g. validated by CI running in the environment lacking the optional dependencies....

It would be ok to stamp the documentation with 'Here be dragons/Tread carefully' on this feature imo.