Feature Request: Alternative `cache-hit` alike output for `restore-keys`

[Danielku15]

I understand that currently it is by design that cache-hit is not set to true if restore-keys is used even though I don't fully understand yet why this is the design decision.

There are various use-cases where as a workflow author I don't care if an exact key or a partial key was matched. As long the cache was restored I can assume that I can skip certain steps thanks to that.

Caches cannot be updated and it is required that we have unique keys. And that breaks quite some workflows where you want to know caches were restored unless you build something custom.

Therefore I propose an alternative output for the scenario where caches were restored using partial keys via restore-keys. My first idea was to have one additional output with following semantics:

• restored-key (string) - Set to the exact key used when restoring the cache regardless of whether restore-keys or key was used on the restore action. Empty if no cache was found and restored.

Use cases:

• Skipping steps where authors don't care whether the key was matched exactly: if: ${{ steps.cache-restore.outputs.restored-key != '' }}
• Pass on the restored key for further custom checks or API calls.

Setting restored-key for both scenarios (key and restore-keys) allows authors a less error prone experience in switching between the two restore modes. If the key ever changes and is required for further steps, no changes have to be made to the workflow beside the cache step.

If this proposal is accepted I would be willing to contribute this feature.

Related issues/discussions:

• https://github.com/actions/cache/issues/1212
• https://github.com/actions/cache/issues/661
• https://github.com/actions/cache/discussions/789

[gabeio]

doesn't that already exist? 👀

https://github.com/actions/cache/blob/main/restore/action.yml#L32

if: ${{ steps.cache-restore.outputs.cache-matched-key != '' }}

https://github.com/actions/cache/tree/main/restore#using-restore-action-outputs-to-make-save-action-behave-just-like-the-cache-action

[Danielku15]

Stupid me 🤦‍♂️. I have completely missed this because it is not available and documented on the main cache action but only on the restore "sub-action":

• https://github.com/actions/cache/blob/704facf57e6136b1bc63b828d79edcd491f0ee84/action.yml#L28-L32
• https://github.com/actions/cache/tree/main?tab=readme-ov-file#outputs
• https://github.com/actions/cache/tree/main?tab=readme-ov-file#skipping-steps-based-on-cache-hit

Closing this issue.