Hide legacy aliases by default and add --all-aliases to `nvm ls`

[jiangzm]

Problem

nvm ls currently displays all built-in aliases, including iojs and historical LTS aliases that have long been EOL.

Most of these aliases resolve to N/A, making the output unnecessarily verbose for users who simply want to inspect installed Node.js versions and active aliases.

As more LTS releases are added over time, the output continues to grow.

Proposal

Add a --all-aliases option to nvm ls.

By default, nvm ls would display only relevant aliases, such as:

• default
• node
• stable
• unstable
• lts/* that resolve to an installed or currently supported release

When --all-aliases is specified, nvm ls would display the complete list of built-in aliases, including historical LTS aliases and iojs.

Benefits

• Cleaner and more readable default output.
• Historical aliases remain available for users who need them.
• Better scalability as additional LTS releases are added.
• Preserves existing functionality through an explicit opt-in option.

[ljharb]

We can't/won't ever depend on the concept of "currently supported" since that changes with the date.

[jiangzm]

We can't/won't ever depend on the concept of "currently supported" since that changes with the date.

Thanks for the clarification. I agree that nvm should not depend on the concept of "currently supported", since that is time-dependent and would require maintaining additional lifecycle information.

My intention is not to make nvm determine which Node.js versions are supported or EOL.

The idea is only about the default display behavior of nvm ls:

• Show the generic aliases (default, node, stable, etc.).
• Show lts/* aliases that point to currently maintained LTS lines by default.
• If a user has installed an old LTS version, show the corresponding lts/<codename> alias as well, because it is relevant to their local environment.
• Hide unused historical aliases (iojs, old lts/<codename> aliases resolving to N/A) unless --all-aliases is specified.

So this would be purely an output filtering/UX improvement, not an attempt to add Node.js lifecycle awareness into nvm.

--all-aliases would still provide the complete existing behavior for users who need to inspect all historical aliases.

[ljharb]

"unused" is subjective and variable. I always have io.js and every old LTS installed on every machine, for testing. How do I arbitrarily draw a line?

[jiangzm]

By "unused", I simply mean aliases that don't correspond to anything in the user's local environment.

If I have Node.js v18 installed, I expect lts/hydrogen to be shown.
If I have io.js installed, I expect iojs to be shown.

For example, this is the kind of output I have in mind:

> nvm ls
       v18.20.8
->     v24.18.0
default -> 24 (-> v24.18.0)
unstable -> N/A (default)
node -> stable (-> v24.18.0) (default)
stable -> 24.18 (-> v24.18.0) (default)
lts/* -> lts/krypton (-> v24.18.0)
lts/hydrogen -> v18.20.8
lts/jod -> v22.23.1 (-> N/A)
lts/krypton -> v24.18.0

Taking iojs as an example, it is a runtime that has been obsolete for more than a decade, and the name itself has no semantic information. For the vast majority of users, it provides no value and may even become distracting information.

The goal is not to remove access to these aliases. --all-aliases could preserve the current complete output for users who need to inspect all historical aliases.

This is only a proposal to make the default output focus on information that is actionable for the user.

[ljharb]

ah, so you're suggesting to hide built-in aliases in nvm ls when they're not installed?

That could work - but showing the alias with "N/A" is an action for the user. It's telling them it's missing and they can install it.

However, perhaps we could always show node and lts/* regardless…