GitHub Action for Towncrier Changelog

Check if a change log entry (fragment file) is present. If present, whether it is named correctly. If not present, whether it is allowed to be missing. Create a .github/workflows/check_changelog_entry.yml as follows. Except for GITHUB_TOKEN, other env entries are optional with defaults shown:

name: Check PR change log

on:
  pull_request:
    types: [opened, synchronize, labeled, unlabeled]

jobs:
  changelog_checker:
    name: Check if towncrier change log entry is correct
    runs-on: ubuntu-latest
    steps:
    - uses: actions/checkout@v5
    - uses: scientific-python/action-towncrier-changelog@v2
      env:
        GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
        BOT_USERNAME: changelog-bot

Your repository must contain a pyproject.toml in the root directory with the appropriate configurations. An example showing all options is:

[tool.changelog-bot]
    [tool.changelog-bot.towncrier_changelog]
        enabled = true  # default is false
        verify_pr_number = true  # default is false
        changelog_skip_label = "no-changelog-entry-needed"  # default is none
        changelog_noop_label = "skip-changelog-checks"
        whatsnew_label = "whatsnew-needed"
        whatsnew_pattern = '''docs\/whatsnew\/\d+\.\d+\.rst'''

[tool.towncrier]
    package = "yourpackagename"
    filename = "CHANGES.rst"
    directory = "docs/changes"
    underlines = "=-^"
    template = "docs/changes/template.rst"

    [[tool.towncrier.type]]
        directory = "feature"
        name = "New Features"
        showcontent = true

    [[tool.towncrier.type]]
        directory = "api"
        name = "API Changes"
        showcontent = true

    [[tool.towncrier.type]]
        directory = "bugfix"
        name = "Bug Fixes"
        showcontent = true

    [[tool.towncrier.type]]
        directory = "other"
        name = "Other Changes and Additions"
        showcontent = true

    [[tool.towncrier.section]]
        name = ""
        path = ""

    [[tool.towncrier.section]]
        name = "yourpackagename.subpackage1"
        path = "subpackage1"

    [[tool.towncrier.section]]
        name = "yourpackagename.subpackage2"
        path = "subpackage2"

    [[tool.towncrier.section]]
    ...

History

This check was originally part of Baldrick bot, used under the terms of the MIT License, contributed by Stuart Mumford (https://github.com/Cadair) for SunPy and Astropy. For reasons now forgotten, the check stopped working for Astropy, so this standalone workflow was created as a "temporarily workaround" until it could be fixed. It was never fixed and has since been removed from Astropy, so now this workflow is permanent and lives in Scientific Python.