[patch] give a more helpful message when lts alias is mistakenly used

[r4reetik]

Issue

When using the command nvm use lts, users encounter the following error message:

N/A: version "lts" is not yet installed.
You need to run nvm install lts to install and use it.

However, the LTS version is already installed on the system, and the command nvm use --lts works correctly. This inconsistency causes confusion and inconvenience for users who expect nvm use lts to function as intended.

Solution

The issue was identified in the nvm_remote_version function within the nvm.sh script. The function did not correctly handle the lts alias, leading to the error message.

To resolve this, I modified the nvm_remote_version function to include a case for the lts alias. The updated function now correctly maps the lts alias to the latest LTS version.

• nvm.sh: Added a case for "lts" to the nvm_remote_version() function to retrieve the latest LTS version using nvm_ls_remote.

Impact

This change ensures that the command nvm use lts correctly maps to the latest LTS version, providing a consistent and expected user experience. Users will no longer encounter the error message when the LTS version is already installed on their system.

[ljharb]

lts isn't an alias, by design - nvm use lts isn't supposed to work.

You can nvm use --lts, or nvm use lts/*, or nvm use lts/argon etc.

(even if i wanted to accept this enhancement, it would need thorough tests)

[r4reetik]

I understand that nvm use lts is not intended for use, but the subsequent error message is misleading, suggesting that nvm install lts should be used instead of nvm install --lts.

If we cannot modify the lts alias without thorough testing, could we at least update the error message to be more accurate in the case of lts?

[ljharb]

Yes, in general the error message can be improved; please do update this PR to do so instead.

[r4reetik]

A change to the nvm_ensure_version_installed function in the nvm.sh script. The change improves the error messaging for users trying to use Node.js LTS versions.

• nvm.sh: Updated the error message to provide specific instructions for installing and using the LTS version of Node.js when PROVIDED_VERSION is set to 'lts'.

[ljharb]

This is fine, but we'll need a test for it.

[ljharb]

LGTM