PR Label Semver Action

This action assists in generating a semantic version change for a codebase based upon the labels applied to the pull request with the end goal of versioning a code package or creating a git tag. It also aids in generating a prerelease version semver which could be used to publish a package to a package registry for beta testing.

Getting Started

First, determine the label naming scheme you want to use to trigger a version change (the names are case insensitive). By default, the action will look for the following labels: major, minor, patch, and the label pattern *prerelease*. If these conflict with your existing labels, you can specify a prefix to instead use labels like: semver:major, semver:minor, semver:patch, and semver:*prerelease*.

Now you can add the action to your workflow. The following example workflow will run on pull request events and will use the default label names:

name: Pull Request Action
on:
  pull_request:
    types: [assigned, labeled, unlabeled, opened, synchronize, reopened, ready_for_review, closed]

# Allow a subsequently queued workflow run to interrupt a previous run
concurrency:
  group: '${{ github.workflow }} @ ${{ github.event.pull_request.head.label || github.head_ref || github.ref }}'
  cancel-in-progress: true

jobs:
  check-code:
    if: ${{ !github.event.pull_request.draft }}
    runs-on: ubuntu-latest
    steps:
      - name: Checkout Code
        uses: actions/checkout@v3
        with:
          ref: ${{ github.ref }}

      - name: Setup Project
        uses: actions/setup-node@v3
        with:
          node-version: '18'
          cache: npm
          cache-dependency-path: package-lock.json

      - name: Generate Semantic Version
        id: semver
        uses: rapidstack/PR-Label-Semver-Action@v1

      - name: Create Git Tag
        uses: actions/github-script@v5
        env:
          TAG: ${{ steps.semver.outputs.string }}
        with:
          script: |
            const { TAG } = process.env
            github.rest.git.createRef({
              owner: context.repo.owner,
              repo: context.repo.repo,
              ref: `refs/tags/v${TAG}`,
              sha: context.sha
            })

      - name: Version NPM Package
        run: node ./scripts/version.js ${{ steps.semver.outputs.string }}

      - name: Publish Prerelease NPM Package
        if: ${{ steps.semver.outputs.prerelease && !github.event.pull_request.merged}}
        run: npm publish --tag next

      - name: Publish Production NPM Package
        if: ${{ github.event.pull_request.merged}}
        run: npm publish

      - name: Create Release
        uses: actions/create-release@v1
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
        with:
          tag_name: v${{ steps.semver.outputs.string }}
          release_name: 'v${{ steps.semver.outputs.string }}: ${{ github.event.pull_request.title }}'
          body: ${{ github.event.pull_request.body }}
          draft: false
          prerelease: ${{ steps.semver.outputs.prerelease }}

Inputs

The following are the inputs that can be passed to the action:

Name	Description	Default
label_prefix	Prefix on PR labels that the action will act on to determine the semver bump. E.g.: value of sv: will look for labels like SV:MAJOR, sv:minor, etc.	(none)
prerelease_prefix	The string to append at the end of a semver for a prerelease version. E.g.: if you set this to 'rc.', the version will be 'x.y.z-rc.{short-hash}'.	pr.
default_bump	For non pull requests (i.e.: workflow_dispatch), the default bump to apply to the version.	patch

Outputs

The action will output the following variables that can be used in subsequent steps by setting an ID on the action:

- name: Generate Semantic Version
  id: semver
  uses: rapidstack/pr-label-semver-action@v1

- name: Create Git Tag
  uses: something/else
    with:
      tag: ${{ steps.semver.outputs.string }}

Name	Description
string	The semantic version string. Looks like: 1.2.3 or 1.2.3-rc.{commit-sha}
major	The major version number.
minor	The minor version number.
patch	The patch version number.
suffix	A portion after the semver for prereleases. By default it looks like: rc.{commit-sha}.
prerelease	A boolean to denote if the semver is a prerelease.
lastMainTag	The last tag on the main branch.