context.config reads from primary branch, not current commit

Bug Report

Current Behavior context.config() reads the configuration from the primary branch (i.e. master) rather than the current commit.

1. Create branch in current repo
2. Add a .github/testconfig.yml with some non-default configuration
3. Commit it to the new branch, and push
4. Open a pull request

  // Your code here
module.exports = robot => {
  robot.on('pull_request.opened', async context => {
    console.log(await context.config('testconfig.yml'));
  });
}

Expected behavior/code The changes made in the pull request should apply to any events run for that pull request (including pull_request, check_suite, check_run, etc).

Environment

• Probot version(s): 6.1.0
• Node/npm version: n/a
• OS: n/a

Possible Solution

When fetching the content of the file, add the additional optional ref parameter. (Possibly via a flag to context.config.)

[rmccue]

I think it makes sense for the default to be master, but it entirely depends on what sort of bot you’re writing. A lot of the probot-based bots I see are related to meta-level things in the repository, and those make sense to use the default branch. However, the bot that I’m primarily working on is for build tools. For things like this, you want to use the config for the specific branch, allowing you to change build rules and see what the result is before merging.

Creating a test repo to try a different build config makes no sense, but it is sensible for repo-level configuration. Making probot a tool only to handle the latter would exclude a lot of use cases. 😃

[stale[bot]]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.