Ruby script that updates all issues on a repo. You can use it to close all issues at once, for example. Uses the GitHub API via Octokit.rb.

main.rb

require 'octokit'

client = Octokit::Client.new access_token: ENV['MY_GITHUB_PERSONAL_TOKEN']
client.auto_paginate = true

repo = 'ORG_NAME/REPO_NAME'

issues = client.issues repo
puts "Repo #{repo} has #{issues.length} issues."

issues.each do |issue|
  num = issue.number
  puts "Updating issue ##{num}..."
  client.update_issue(repo, num, state: 'closed')
end