Add an output to differentiate between partial and full matches

[Flamefire]

Currently outputs.cache-hit can be used to check if an "exact match" for a cache was found and restored.

In some workflows there is a need for updating a cache entry and basically doing that continuously. E.g. for cron-task workflows where an old cache is loaded, worked on then saved and should be reused for the next cron-invoke

The current best approach to support this is:

    - uses: actions/cache@v2
      id: cache-test
      with:
        path: cacheFolder
        key: cache-${{ github.run_id }}
        restore-keys: cache-

This will create a unique key per cache but restore the latest one. As long as this is run once a week the cache will "persist" long enough to be reused by the next run.

Now the problem is that a step guarded by if: steps.cache-test.outputs.cache-hit != 'true' is always executed because it did restore a cache just not an exact hit which is by design. But now I can't run a specific step only if no cache was found at all.

So I'd like a steps.cache-test.outputs.cache-restored output that is true when ANY cache was restored even those with partial matches

[github-actions[bot]]

This issue is stale because it has been open for 365 days with no activity. Leave a comment to avoid closing this issue in 5 days.

[Flamefire]

Not stale

[Phantsure]

There is work going on here. There was a similar PR. You may want to track work related to granular cache control here: https://github.com/actions/cache/discussions/1020

[kotewar]

We have added a new restore action that outputs the name of the primary key and the matched key, these outputs can be used to achieve the desired outcome. Hence closing this issue.