pr-commenter

Create and manage automatic comments in a Github PR

pr-commenter is CLI app to add a comment a Github PR based on content from stdin, files or environment variables.

You can create a new comment, hide a previous one of the same type or update the "current" one from a different process. This is done with a hidden metadata added to the comment so it could be detected in a subsequent run, and update or hide previous messages if needed.

Basic usage

Create a Github token with repo scope and export it as PR_COMMENTER_GITHUB_TOKEN environment variable

pr-commenter your/repo 12 comment.txt

Or from the standard input, using - as the file name

cat comment.txt | pr-commenter your/repo 12 -

This will simply create a new comment in the PR 12 with the content of comment.txt But there is much more.

Advanced example

Suposse you have a template failed_tests.j2 like this

{% if not is_append %}## Failed tests{% endif %}
 
[suite {{ CI_SUITE_NAME }}]({{ CI_SUITE_URL }}):

```bash
{% for line in input_lines %}{{ line }}
{% endfor %}

Then your test-runner produces a file failures.txt with the list of failed tests like this:

tests/test_client.py::test_client_simple
tests/test_client.py::test_client_complex

So we want to add a single comment to the PR with the failed tests for two different suites executions triggered by the same "commit".

In the post-build phase of both suites, you can run something like

pr-commenter your/repo $PR failures.txt -t failed_tests.j2 --build=$COMMIT

The first suite that finish will post a comment like this

<!-- pr-commenter: failed_tests.j2 abc123 -->
## Failed tests
 
[suite client](http://the-client-url):

```bash
tests/test_client.py::test_client_simple
tests/test_client.py::test_client_complex
```

Then the second suite will find that previous comment that was for the same template and same and commit ("abc123" in the example), so pr-commenter will edit the comment and append the new content.

The result will be something like this:

<!-- pr-commenter: failed_tests.j2 abc123 -->
## Failed tests
 
[suite client](http://the-client-url):

```bash
tests/test_client.py::test_client_simple
tests/test_client.py::test_client_complex
```

[suite server](http://the-server-url):

```bash
tests/test_server.py::test_server_1
```

In a next commit, the first suite that finishes will post a new comment, but this time the commit will be different, so the previous "abc123" comment will be minimized.

Templates

It uses Jinja2 templates. The stdin/files is passed and a variable input_lines And is_append will be True in case the new comment will be appended to an existent one (so you can ommit the header or footer, for instance).

In addition, the complete os.environ dictionary is passed, so all the environment variables are available in the template.

Install

• Install the package with pipx

pip install --user pipx
pipx install pr-commenter

Alternatively, with pip

pip install --user pr-commenter

• Create a Github token with repo scope and export it as PR_COMMENTER_GITHUB_TOKEN environment variable