Get pull request number from action

[estensen]

I'm trying to create an action that is triggered on a PR and tags a specified reviewer. For that I'm creating an action which uses the GitHub API to create a review request. To create this request I need the pull request number. The action is triggered by a PR, but I can't find the pull request number in the action logs.

[peter-evans]

You can extract the PR number from the environment variable GITHUB_REF. For on: pull_request workflows GITHUB_REF takes the format refs/pull/:prNumber/merge.

ref: https://help.github.com/en/github/automating-your-workflow-with-github-actions/events-that-trigger-workflows#pull-request-event-pull_request

[estensen]

Thanks! I also found this:
pull_number=$(jq --raw-output .pull_request.number "$GITHUB_EVENT_PATH")

[n1ru4l]

Javascript version

"use strict";

const parsePullRequestId = githubRef => {
  const result = /refs\/pull\/(\d+)\/merge/g.exec(githubRef);
  if (!result) throw new Error("Reference not found.");
  const [, pullRequestId] = result;
  return pullRequestId;
};

const main = async () => {
  const pullRequestId = parsePullRequestId(process.env.GITHUB_REF);
};

main().catch(err => {
  console.error(err);
  process.exitCode = 1;
});

[littlebtc]

Today I found that the PR number will be missing if you re-run the job for on: pull_request workflow. The only reliable way to get it is through $GITHUB_EVENT_PATH.

const fs = require('fs')
const ev = JSON.parse(
  fs.readFileSync(process.env.GITHUB_EVENT_PATH, 'utf8')
)
const prNum = ev.pull_request.number

I think it is kind of a bug of GitHub Actions. 😭

[jpfeuffer]

I also think this is an important feature and it is a shame that this issue is closed "since you can hack your way around it". :(

[salvamomo]

In case this is still useful to anybody, a simple shell solution:

PR_NUMBER=$(echo $GITHUB_REF | awk 'BEGIN { FS = "/" } ; { print $3 }')

[leeyspaul]

Did anyone attempt to get the $GITHUB_REF but have a return with no PR number in the output? For example, my output is something like refs/head/master but has no pull number. Would love to see if anyone had a solution for this.

[leeyspaul]

Did anyone attempt to get the $GITHUB_REF but have a return with no PR number in the output? For example, my output is something like refs/head/master but has no pull number. Would love to see if anyone had a solution for this.

Replying to myself, I didn't run actions/checkout before ${{github.event.issue.number}}!