Using a issue_comment trigger re-run of checks.

[mckaymatt]

I have an app that listens for pull_request.opened and pull_request.synchronize to runs checks.

Sometimes someone will switch the branch that is being merged into, or there will be a network error, and for whatever reason I would like to be able to re-run all the checks as if the pull_request.opened/synchronize webhook were re-sent.

I was thinking of triggering this re-run when someone makes a comment like "retest" on the PR, which would be issue_comment.created webhook.

The problem is that all my functions downstream of app.on depend pretty heavily on the types provided by EventPayloads.WebhookPayloadPullRequestPullRequest from (i think) @octokit/webhooks/dist-src/generated/event-payloads. The payload from issue_comment is quite different. To initiate a retest I would need to:

1. query GitHub for the data not provided using context.octokit.rest.pulls.get
2. use some other data type besides WebhookPayloadPullRequestPullRequest.

My questions:

1. Is there an easier way, like triggering a hook to resend?
2. If not, is there a way to coerce types so something like RestEndpointMethodTypes["pulls"]["get"]["response"] can become WebhookPayloadPullRequestPullRequest?
3. Is there a more generic pull-request data type that isn't specifically tied a webhook. Thus far all I can think to do is always call context.octokit.rest.pulls.get({repoOwner, repoName, pullNumber}) from either pull_request or issue_comment. That involves one extra API call and complicates my tests. This is basically what I envision it looking like:

app.on(['pull_request.opened', 'pull_request.synchronize'], async context => {
  // unpack params
  // discard all the PR info that came from the hook.
  await mainPullRequestChecks({ owner: repoOwner, repo: repoName, pull_number: pullNumber })
}
app.on(['issue_comment.created'], async context => {
  // unpack params
  // Check for special string in comment to retest.
  await mainPullRequestChecks({ owner: repoOwner, repo: repoName, pull_number: pullNumber })
}

function mainPullRequestChecks (owner: string, repo: string, pull_number: number) {
  // Now we only deal with one type but add an extra API call to every event.
    const pullRequest = await context.octokit.rest.pulls.get(
      { owner: repoOwner, repo: repoName, pull_number: pullNumber }
    )
  // All checks below
}

My dependencies

  "dependencies": {
    "@octokit/rest": "^18.5.3",
    "js-yaml": "^4",
    "probot": "^11.3.0",
    "typescript": "^4.2.4"
  },

[mckaymatt]

I just realized that adding 'pull_request.reopened' as a trigger would probably be an easy way to deal with this. A developer could close a PR than reopen it to re-run tests.
I could even possibly add a probot-command to do it automatically if someone entered a command like /retest

app.on(['pull_request.opened', 'pull_request.synchronize', 'pull_request.reopened'], async context => {

Hopefully someone else finds this rubberduck session helpful.