GitHub action to create new SemVer tags based on PR labels

This action looks for specific labels (by default bump:major, bump:minor, and bump:patch) on PRs, and creates a new SemVer tag based on the current latest version of the repository after a PR with one of the labels is merged.

Currently, the action doesn't allow customizing the tag format. It will always look for SemVer version tags prefixed with v and will create such tags.

The action adds a PR comment which shows what will happen if the PR is merged. The comment is updated when labels are added or removed, if the workflow has the appropriate triggers (see section "Usage").

The action can optionally trigger follow-up workflows (for example if you want to automatically create a release after a new tag has been created). This feature requires that any workflows that should be triggered by the action have the workflow_dispatch trigger option.

Usage

To use the action with the default configuration you can use the following workflow config:

on:
  pull_request:
    # Run when PR head branch is updated (synchronize), when the set of PR
    # labels is changed (labeled, unlabeled), and after the PR is closed. We
    # additionally check for `merged==true` in the event payload on `closed`
    # before actually pushing the tag.
    types:
      - synchronize
      - labeled
      - unlabeled
      - closed

steps:
  - name: Create new tag
    uses: projectsyn/pr-label-tag-action@v1

Triggering follow-up actions

on:
  pull_request:
    types:
      - synchronize
      - labeled
      - unlabeled
      - closed

steps:
  - name: Create new tag
    uses: projectsyn/pr-label-tag-action@v1
    with:
      trigger: |
        Release

See this repository's "Release" workflow for an example workflow that is be triggered correctly on both manually pushed tags, and tags created by this action.

Action inputs

Name	Description	Default
github-token	Token to access GitHub	github.token
patch-label	Label which indicates a patch-level SemVer bump	bump:patch
minor-label	Label which indicates a minor-level SemVer bump	bump:minor
major-label	Label which indicates a major-level SemVer bump	bump:major
trigger	Workflow names of workflows that should be triggered when a new tag is created. Multiple workflows can be specified on separate lines.	""
release-comment	Comment that gets posted when a tag will be pushed on merge	"🚀 Merging this PR will release `<next-version>`"
released-comment	Comment that gets posted when a tag has been pushed	"🚀 This PR has been released as [`<next-version>`](<release-url>)"
unmerged-comment	Comment that gets posted when a labeled PR gets closed unmerged	"This PR has been closed unmerged. No new release will be created for these changes"

For inputs release-comment, released-comment and unmerged-comment the action supports the following placeholders:

• <next-version> is replaced with the computed new version
• <release-url> is replaced with the URL to the new tag