Would you consider ref tag type without event? #253

Behaviour

Steps to reproduce this issue

Execute the action with only the ref tag type:
tags: | type=ref

Expected behaviour

Depending on the event, it should select the appropriate event type.
On a tag push, select the tag event type.
On a branch push, select the branch event type.

Actual behaviour

For now it fails with Missing event attribute for type=ref

Configuration

• Repository URL (if public):
• Build URL (if public):

on:
  push:
jobs:
  demo:
    steps:
      # Setup
      - uses: actions/checkout@2541b1294d2704b0964813337f33b291d3f8596b  # v3.0.2
      - uses: docker/metadata-action@57396166ad8aefe6098280995947635806a0e6ea  # v4.1.1
        with:
          images: my_dummy_image
          tags: |
            type=ref

Logs

Download the log file of your build
and attach it to this issue.