comment-on-pr/entrypoint.sh

#!/usr/bin/env ruby

require "json"
require "octokit"

json = File.read(ENV.fetch("GITHUB_EVENT_PATH"))
event = JSON.parse(json)

github = Octokit::Client.new(access_token: ENV["GITHUB_TOKEN"])

if !ENV["GITHUB_TOKEN"]
  puts "Missing GITHUB_TOKEN"
  exit(1)
end

if ARGV[0].empty?
  puts "Missing message argument."
  exit(1)
end

message = ARGV[0]
check_duplicate_msg = ARGV[1]
duplicate_msg_pattern = ARGV[2]

repo = event["repository"]["full_name"]

if ENV.fetch("GITHUB_EVENT_NAME") == "pull_request"
  pr_number = event["number"]
else
  pulls = github.pull_requests(repo, state: "open")

  push_head = event["after"]
  pr = pulls.find { |pr| pr["head"]["sha"] == push_head }

  if !pr
    puts "Couldn't find an open pull request for branch with head at #{push_head}."
    exit(1)
  end
  pr_number = pr["number"]
end

coms = github.issue_comments(repo, pr_number)

if check_duplicate_msg == "true"
  if duplicate_msg_pattern != nil
    duplicate = coms.find { |c| (c["body"] =~ (Regexp.new duplicate_msg_pattern)) != nil }
  else
    duplicate = coms.find { |c| c["body"] == message }
  end

  if duplicate
    puts "The PR already contains this message"
    exit(0)
  end
end

github.add_comment(repo, pr_number, message)