[rush] Fix an issue with rush install in large repos on Windows.

[iclanton]

Summary

This PR fixes an issue that was introduced in #4653.

Details

There is an issue where rush install and rush update will fail with an ENAMETOOLONG error on Windows in repos with a large number of projects. This is because Rush now calls pnpm install with --filter arguments for each project whose dependencies are being installed even if all projects are being installed.

This change updates the pnpm parameter generation algorithm to not generate any --filter arguments if all projects are being installed.
  

How it was tested

Tested in a repo that was failing with the error described above.

Impacted documentation

None.

[octogonz]

Can you add a comment explaining what this is doing? Not everybody is familiar with PowerShell particularly with the ${{ macro superimposed on its syntax.

Something like:

# Create a .rush-user/settings.json file containing a configuration such as this:
#
#   { "buildCacheFolder":  "/home/runner/work/rushstack/rushstack/rush-cache" }
#
# This is... ❓❓❓

Actually I have no idea what it is. .rush-user/settings.json is not documented anywhere on the website. Are users supposed to create it? Is this an internal implementation detail? What is this CI step doing?

[iclanton]

Did that never get documented? It's how users configured a machine-wide Rush cache location.

[octogonz]

Why do we need another copy of the repo?

[iclanton]

During the second rush install run, the common/temp/<subspace>/pnpmfileSettings.json files have a property ("semverPath") that records where our generated pnpmfile can get the semver package. Running rush install on Rushstack with Rush in the current repo was causing an problem where the common/temp/default/node_modules folder is removed and recreated, so the "semverPath" points at a path that doesn't exist during the second subspace's installation.

[octogonz]

This description is too vague.

* An array of `--filter` arguments.  For example, if the array is ["a", "b"] then Rush would invoke
* `pnpm install --filter a --filter b` which restricts the install/update to dependencies of
* workspace projects "a" and "b".  If the array is empty or undefined, then an unfiltered install
* is performed.  Filtered installs have some limitations such as less comprehensive version analysis.

[iclanton]

This is actually just an array of arguments, including the --filter arguments.

[octogonz]

Is selectedProjects actually needed any more? From what I can tell, it is only ever used by this code:

rushstack/libraries/rush-lib/src/logic/base/BaseInstallManager.ts

Lines 167 to 170 in 236a0e5

	const selectedProjectNames: string[] = [];
	for (const { packageName } of selectedProjects) {
	selectedProjectNames.push(packageName);
	}

...which just constructs a set of installed project names for last-install.flag to track. But isn't that exactly the same list as pnpmFilterArguments?

[iclanton]

No, we aren't generating --filter args for every project anymore when doing a filtered install outside of subspace unless someone says rush install --only <something>. For the --to case, for example, we're generating args that use the pnpm filter syntax: https://pnpm.io/filtering

[dmichon-msft]

Should be using getSubspacesForProjects defined above to avoid duplicate processing of the metadata.