GitHub Action to check pull requests (PRs) for the presence or absence of specified labels

• We couldn't find another label checker that had all our 4 check types (one_of, none_of, all_of, any_of)

• Speed: the Docker image used for the checks is only 2.7 MB, so the checks are blazingly fast (c. 3 seconds)

• Prefix mode: check for the presence or absence of labels beginning with a certain prefix

Using this action is as simple as:

1. create a .github\workflows directory in your repository

2. create a YAML file in the .github\workflows directory (file name can be anything you like, with either a .yml or .yaml file extension), with this example content:

   ---
   name: Label Checker
   on:
     pull_request:
       types:
         - opened
         - synchronize
         - reopened
         - labeled
         - unlabeled
   
   jobs:
   
     check_labels:
       name: Check labels
       runs-on: ubuntu-latest
       steps:
         - uses: docker://agilepathway/pull-request-label-checker:latest
           with:
             one_of: major,minor,patch
             repo_token: ${{ secrets.GITHUB_TOKEN }}
   

3. customise the label checks in the with section of the YAML file to fit your needs

   (see the checks section below for the different checks you can configure)

There are 4 types of label checks available:

• one_of (PRs must have exactly one of these labels)

• none_of (PRs must have none of these labels)

• all_of (PRs must have all of these labels)

• any_of (PRs must have one or more of these labels)

You can have as many of the checks configured in the same YAML file as you like.

• Semantic versioning: one_of: major,minor,patch

• Each PR must be a bug or an enhancement: one_of: bug,enhancement

• Prohibit certain labels: none_of: invalid,wontfix,duplicate,question

• Require each PR to have a certain label: all_of: enhancement

  or labels: all_of: enhancement,reviewed

• Require each PR to have one or more of these labels: any_of: documentation,enhancement,bug

with:
  one_of: major,minor,patch
  none_of: invalid,wontfix,duplicate,question
  any_of: documentation,enhancement,bug
  repo_token: ${{ secrets.GITHUB_TOKEN }}

jobs:
 
  check_semver_label:
    name: Check for semantic version label
    runs-on: ubuntu-latest
    steps:
      - uses: docker://agilepathway/pull-request-label-checker:latest
        with:
          one_of: major,minor,patch
          repo_token: ${{ secrets.GITHUB_TOKEN }}

  check_pull_request_type:
    name: Check for pull request type label
    runs-on: ubuntu-latest
    steps:
      - uses: docker://agilepathway/pull-request-label-checker:latest
        with:
          one_of: bug,enhancement
          repo_token: ${{ secrets.GITHUB_TOKEN }}

You can set the label checker to check for the presence or absence of labels starting with the given prefix.

This prefix label checking is a powerful feature that allows pull requests to have scoped labels, similarly to GitLab.

Set the prefix_mode as an input parameter in the with section: prefix_mode: true (it is an optional parameter as it defaults to false).

Example:

steps:
  - id: prefix_label_check
    uses: docker://agilepathway/pull-request-label-checker:latest
    with:
      prefix_mode: true
      one_of: "type:"
      repo_token: ${{ secrets.GITHUB_TOKEN }}

This example will pass if there is exactly one label on the pull request starting with type:

You can use any string as the prefix (it doesn't need to contain a :, that's just one example)

You can use one_of, any_of, none_of when checking prefixes, but you cannot use all_of (as all_of does not make sense when checking for labels starting with the given prefix).

You can only specify one prefix at a time. For instance you cannot specify one_of: "type:","visibility/". You can specify multiple prefix checks of the same type though.

You can set the label checker to not fail the build, even when a label check fails, and then use an if condition in a subsequent step or job to conditionally do something or not. For example: check if a pull request has a preview label and then only deploy an ephemeral environment if so.

Set the allow_failure mode as an input parameter in the with section: allow_failure: true (it is an optional parameter as it defaults to false).

Example:

steps:
  - id: preview_label_check
    uses: docker://agilepathway/pull-request-label-checker:latest
    with:
      all_of: preview
      repo_token: ${{ secrets.GITHUB_TOKEN }}
      allow_failure: true
  - if: steps.preview_label_check.outputs.label_check == 'success'
    run: echo deploy to ephemeral environment

The label checker always exposes the label_check step output variable, regardless of whether allow_failure is set or not. The variable has a value of either success or failure which can then be queried in subsequent steps, as in the above example.

To use this label checker with GitHub Enterprise, specify the GitHub Enterprise GraphQL URL in an input, e.g. for Enterprise Cloud:

jobs:

  check_labels:
    name: Check labels
    runs-on: ubuntu-latest
    steps:
      - uses: docker://agilepathway/pull-request-label-checker:latest
        with:
          github_enterprise_graphql_url: https://api.github.com/graphql
          one_of: major,minor,patch # just an example
          repo_token: ${{ secrets.GITHUB_TOKEN }}

or for Enterprise Server:

jobs:

  check_labels:
    name: Check labels
    runs-on: ubuntu-latest
    steps:
      - uses: docker://agilepathway/pull-request-label-checker:latest
        with:
          github_enterprise_graphql_url: https://<hostname>/api/graphql
          one_of: major,minor,patch # just an example
          repo_token: ${{ secrets.GITHUB_TOKEN }}

The project is open source and all contributions are very welcome 🙂 💥 👍

• How to report a bug or suggest a new feature

• How to make a contribution

• Local development

• Running the tests

See the DEPENDENCIES.md