Be able to run nx print-affected with npx for fast CI

[Lp-Francois]

Description

In CI, we want to be able to determine if some apps were affected by the changes without having to install the node_modules which can be really big in the case of monorepo (in our case 3G)

$ npx nx print-affected --type=app --select=projects --plain --base $AFFECTED_BASE --head HEAD

 >  NX   Could not find Nx modules in this workspace.

   Have you run npm/yarn install?

Motivation

Speed up the CI process and improve Developers experience. Especially with big monorepo, downloading the cached node_modules takes quite some time.

Especially with CI like vercel where it is possible to use a script checking if we should skip the build, running `print-affected fast enough is really helpful.

Related issue: #8448 where running npm install will install the whole node_modules, which we don't want.

Current workaround we found

We moved the package.json and package-json.lock to a .bk extension, installed nx and then ran the command print-affected without error.

Related issues: from 2 years ago with the deprecated command - #5752

[Weetbix]

This is an important feature for monorepo tooling, our npm install takes upwards of 4 minutes before we can determine if a task even needs to be run.

[zwily]

@Lp-Francois I'm trying your workaround, but my nx command is failing without printing anything:

npx --yes nx show projects --affected --base=HEAD^ --projects "apps/*"

Any idea what's going on? Does nx need to be installed locally in the project to run an affected command? (npx --yes nx is installing a global one according to npx --yes nx --version)

Edit to add: This command works fine locally.

[Lp-Francois]

Hey, I am not sure why it doesn't work for you 🤔
In local it works for me

Maybe try to add nx in your node_modules before running the workaround?

[martinmicunda]

The same feature was requested in this closed issue #4710 and #16381

[FrozenPandaz]

We need more discussion on this topic.

1. There is nx-ignore which handles this.
2. At this point, at least some packages will have to be installed to properly create the graph.
3. It's easy for this to have false negatives.