# Pull Request Title Checker

<!-- prettier-ignore -->
This action checks if PR titles conform to the Contribution Guidelines :ballot_box_with_check: <br/><br/>
Consistent title names help maintainers organise their projects better :books: <br/><br/>
Shows if the author has _reaaaaally_ read the Contribution Guidelines :P

## Usage

Create a config file `.github/pr-title-checker-config.json` like this one below:

```json
{
  "LABEL": {
    "name": "title needs formatting",
    "color": "EEEEEE"
  },
  "CHECKS": {
    "prefixes": ["fix: ", "feat: "],
    "regexp": "docs\\(v[0-9]\\): ",
    "regexpFlags": "i",
    "ignoreLabels" : ["dont-check-PRs-with-this-label", "meta"]
  },
  "MESSAGES": {
    "success": "All OK",
    "failure": "Failing CI test",
    "notice": ""
  }
}
```
You can pass in one of `prefixes` or `regexp` or even both based on your use case. `regexpFlags` and `ignoreLables` are optional fields.

If `LABEL.name` is set to `""`, adding or removing labels will be skipped. The CI test will continue to pass/fail accordingly.

If none of the checks pass, a label will be added to that pull request. \
If at least one of them passes, the label will be removed.

This action causes CI tests to fail by default. However, if you do not want CI tests failing just because of this action, simply set `alwaysPassCI` as true in the CHECKS field. **An invalid config file will always cause the action to fail.**

Adding label names to the optional `ignoreLabels` field will forfeit any checks for PRs with those labels.

The config file is always pulled from the action's context, i.e., the branch from which the pull request is made.

See [other ways to specify config file.](#other-ways-to-specify-config-file)

## Create Workflow

Create a workflow file (eg: `.github/workflows/pr-title-checker.yml`) with the following content:

```yaml
name: "PR Title Checker"
on:
  pull_request_target:
    types:
      - opened
      - edited
      - synchronize
      - labeled
      - unlabeled

jobs:
  check:
    runs-on: ubuntu-latest
    steps:
      - uses: thehanimo/pr-title-checker@v1.4.1
        with:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
          pass_on_octokit_error: false
          configuration_path: .github/pr-title-checker-config.json #(optional. defaults to .github/pr-title-checker-config.json)
```

To learn more about workflows, see [Create an example workflow.](https://docs.github.com/en/actions/using-workflows/about-workflows#create-an-example-workflow)

## Other ways to specify config file

### 1. Remote URL to a valid JSON file
```yaml
...
    steps:
      - uses: thehanimo/pr-title-checker@v1.4.1
        with:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
          pass_on_octokit_error: false
          remote_configuration_path: "https://raw.githubusercontent.com/grpc/grpc/master/.github/pr_title_checker_config.json"
...
```
Note that this has to be a url pointing to a valid, raw json file. See [#28](https://github.com/thehanimo/pr-title-checker/issues/28)

### 2. Config file in a GitHub repo
```yaml
...
    steps:
      - uses: thehanimo/pr-title-checker@v1.4.1
        with:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
          pass_on_octokit_error: false
          github_configuration_owner: RocketChat #(optional. defaults to the owner of the repo in which the action is run)
          github_configuration_repo: Rocket.Chat #(optional. defaults to the repo in which the action is run)
          github_configuration_path: .github/pr-title-checker-config.json #(optional. defaults to .github/pr-title-checker-config.json)
          github_configuration_ref: <named branch, tag, or SHA> #(optional. defaults to the latest commit on the default branch or, if the repo specified is the same as the one on which the action is running, it defaults to the current context's sha)
          github_configuration_token: ${{ secrets.YOUR_TOKEN }} #(optional. defaults to GITHUB_TOKEN)
...
```

### 3. Config file in the local file system of the action
```yaml
...
    steps:
      - uses: thehanimo/pr-title-checker@v1.4.1
        with:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
          pass_on_octokit_error: false
          local_configuration_path: .github/actions/enforce-pr-titles/config.json
...
```
This is useful if a repo containing the config file is pulled in a previous step using, for e.g., actions/checkout. See [#36](https://github.com/thehanimo/pr-title-checker/issues/36)


## NOTE:
* [`pull_request_target`](https://docs.github.com/en/actions/learn-github-actions/events-that-trigger-workflows#pull_request_target) event trigger should be used (not [`pull_request`](https://docs.github.com/en/actions/learn-github-actions/events-that-trigger-workflows#pull_request)) in order to support checking PRs from forks. This was added in `v1.3.2`. See [#8.](https://github.com/thehanimo/pr-title-checker/issues/8)
* `pass_on_octokit_error` is an optional input which defaults to false. Setting it to true will prevent the CI from failing when an octokit error occurs. This is useful when the environment this action is run in is not consistent. For e.g, it could be a missing GITHUB_TOKEN. Thanks to [@bennycode](https://github.com/bennycode) for pointing this out.