GitHub Action - Establish Context

This GitHub action establishes the context for a release. It outputs whether a release should be triggered, the release type (major, minor, patch, prerelease), which version the repository is currently on and whether or not the release was triggered as part of a cascading release.

When workflow is triggered by a pull_request event with type = closed it will look for major, minor and patch labels on the pull request and use the 'greatest' release type. Only pull requests merged to the 'master'/'main' branch and given prerelease branches will trigger releases.

Usage

Create a workflow .yml file in your .github/workflows directory. An example workflow is available below.

Note that the workflow has to be able to be triggered by a closed pull_request event for it to work properly. See onin the example workflow below.

For more information, reference the GitHub Help Documentation for Creating a workflow file

Inputs

• token: The token to use for the GitHub API. default: ${{ github.token }}
• prerelease-branches: A comma separated list of prerelease identifier suffixes to branch names that when merged a PR to will trigger a prerelease. default: ''
• current-version: If the version is known, you can specify it with this. default: ''
• version-file: If the version is in a file adhering to the expected JSON format, use this. default: ''

Version File

Using the version file strategy requires a file that contains an object literal with a property called version with a string type:

{
  "version": "1.0.0"
}

prerelease-branches

A comma separated list of prerelease identifiers. It will output should-publish = true whenever a pull request is merged to a branch with a name which is a version with one of the given prerelease-branches identifers. It will also make sure to use the version in the branch name as part of the outputted current-version and use the latest version that is tagged that is equal to that prerelease version. For instance if a pull request is merged to the branch 2.0.0-alpha and the repository has a tag named 2.0.0-alpha.20 should-publish should be true, current-version should be 2.0.0-alpha.20 and release-type should be prerelease. If there are no tags starting with 2.0.0-alpha then that will be the current-version output.

environment-branch

If you're releasing things on a branch that represents a specific environment, putting the branchname in here will consider any merged pull requests to be a pre-release to it. For instance typical use would be development, testing, staging or similar. This will cause the should-publish output to be set to true. The current-version output will include the version number and a -{branchname} added to it. The output release-type will be set to prerelease.

Outputs

• should-publish: Whether or not the pipeline should publish
• current-version: The current version of the repository derived from the tags or 0.0.0 if there are no version tags
• release-type: The type of the release. Either major, minor, patch or prerelease
• cascading-release: Whether the publish was triggered by a cascading release

Example Workflow

on:
  push:
    branches:
    - '**'
  pull_request:
    types: [closed]

name: Establish Context

jobs:
  context:
    name: Establish Context
    runs-on: ubuntu-latest
    steps:
      - name: Checkout code
        uses: actions/checkout@v2
      - name: Establish Context
        id: context
        uses: dolittle/establish-context-action@v2

Example Workflow - with prerelease branches

on:
  push:
    branches:
    - '**'
  pull_request:
    types: [closed]

name: Establish Context

jobs:
  context:
    name: Establish Context
    runs-on: ubuntu-latest
    steps:
      - name: Checkout code
        uses: actions/checkout@v2
      - name: Establish Context
        id: context
        uses: dolittle/establish-context-action@v2
        with:
          prerelease-branches: alpha,beta,rc

Contributing

We're always open for contributions and bug fixes!

Prerequisites

• node <= 12
• yarn
• git