Originally based on the actions TS template, it checks for the presence/absence of a string or group of strings in the body or diff in a PR, as well as certain conditions on the PR: number of files changed, and number of lines changed.

It uses the GitHub API, so you'll need to provide a token. Don't worry, that's built-in.

You would need to put this in a YAML file in the .github/workflows directory

name: "Check PR content"
on: [pull_request]

jobs:
  check_pr:
    runs-on: ubuntu-latest
    steps:
    - name: Check PR
      uses: JJ/github-pr-contains-action@releases/v10
      with:
        github-token: ${{github.token}}
        bodyDoesNotContain: "Delete|this"
        bodyContains: 'Test'
        diffContains: ';'
        diffDoesNotContain: "TODO|to do"
        filesChanged: 1
        linesChanged: 1
        waivedUsers: ["dependabot[bot]"]

The bodyContains variable will include the string that we want the body of the PR to include, such as checked items in a checklist; obviously bodyDoesNotContain will hold the opposite, what we don't want to see in the PR body. Any of them can have a | separated list of words or expressions. The PR will check it contains any of the words in bodyContains and none of the words in bodyDoesnotContain.

Same patterm for diff(Contains|DoesNotContain). Can be a word or list of words you want in the diff (for instance, you want it to always change code so it contains a statement terminator) or don't want in the diff (for instance, you don't want it to include TODOs because people never ever do them).

These strings are unwittingly converted into regular expressions, so any regular expression will also work; []()+?* are escaped so that things such as [.] work with the literal meaning. They can be left empty if you don't need that specific check.

Finally, waivedUsers is a YAML array that contains the users that will be spared from running these checks; if the PR is triggered by one of those users, it will exit with a warning and with a green status. By default, it has the value ["dependabot[bot]"]. If you want to edit more and want to keep dependabot PRs from failing, add it to your list.

An example is used as .github/workflows/check-PRs-here.yaml in this repository as well as this one, which is the one I use for testing.

You might want to qualify possible events that trigger this action, for intance, this way:

  pull_request:
    types:
      [opened, edited, assigned, closed, , synchronize, review_requested, ready_for_review]

This will skip diff checks every single push, for instance. Please remember that this action will only work in pull requests, since it checks the pull request object payload. It will simply skip any check (with a warning) if it is not triggered by a pull_request or pull_request_target event.

For instance, you might want to use a GitHub action such as this one for the CONTRIBUTORS.md file:

name: "Check contributors file additions"
on:
  pull_request:
    types: [opened, edited]
    paths:
      - CONTRIBUTORS.md

jobs:
  check_pr:
    name: "Checks contributors"
    runs-on: ubuntu-latest
    steps:
      - name: Check PR
        uses: JJ/github-pr-contains-action@releases/v10
        with:
          github-token: ${{github.token}}
          linesChanged: 1
          filesChanged: 1
          diffContains: github.com/
          waivedUsers: ["dependabot[bot]","CompanyBigWig"]

It would check that there's only a single file modified (because why would you need to change another, if all you want is to add your name to the contributors' file), a single line is changed (because you're only one, right?) and that it includes a link to your GitHub profile by forcing the diff to contain that string.

This GitHub action works as is in public repositories. Diff checking will simply be disabled if it detects it is being run in a private repository.

Any suggestion, bug report, etc, is appreciated. Please check out or create an issue before contributing a PR, if possible.

There are several forks of this action, with additional features:

• PR content checker by @jsoares includes diffDoesNotContain
• Francisco Giordano's pr-content-checker
• Pablo Statsig's pr-content-checker

• v0: proof of concept, published to marketplace
• v1: Adds several more checks
• v2: Adds check for strings to avoid and creates issues for errors.
• v3: Changes packaging, upgrades modules, deletes unneeded files.
• v4: Solves a number of issues.
• v5: Will not use diffContains if it's an empty string
• v6: can use words or regular expressions in bodyContains/ bodyDoesNotContain
• v7: includes more "rexified" characters: *,?,+
• v8: adds diffDoesNotContain and extends regex testing to diff tests.
• v9: adds some informative messages, disables API calls for private repositories.
• v10: Skips checks if not in a pull request; adds information to prevent this use too.
• v11: Adds a configuration variable that skips users, with dependabot skipped by default (or passed through).

This is a modification of the original template, and is released under the MIT license.