npmrc environment variable fallback

[rburgst]

• I'd be willing to implement this feature (contributing guide)

Describe the user story

As a devops engineer I would like to be able to use fallback values for environment variables similar to what yarn berry allows.

Describe the solution you'd like

in yarn this works as follows in .yarnrc.yml

  scope:
    npmAlwaysAuth: true
    npmAuthIdent: "${AUTH_IDENT:-fallback_value}"

so in .npmrc it would be nice to use the same syntax

@scope:registry=https://registry.server/npm/scope/
//registry.server/npm/scope/:_authToken=${AUTH_IDENT:-fallback_value}

Describe the drawbacks of your solution

Cant think of any drawbacks, really.

Describe alternatives you've considered

Otherwise you would need to dynamically create the .npmrc file in your GH actions, which is a hassle.

[zkochan]

I don't have objections.

[rburgst]

@zkochan can we get the PR pnpm/components#10 in?