DangerFile - Danger System - script to check conventional commits titles and size of the PR

Dangerfile.rb

# https://www.regextester.com/109925
CONVENTIONS_URL = "your link"

def validate_title_format
    def valid_title_format?(title)
        conventional_commit_regex = /^(build|chore|ci|docs|feat|fix|perf|refactor|revert|style|test)(\(.*\))?: .*$/
        result = title =~ conventional_commit_regex
        result != nil
    end

    def is_capitalized?(text)
        /[[:upper:]]/.match(text)
    end

    def find_title_error(title)
        if !valid_title_format?(title)
            return """
               # Issue
               - This PR title \"#{title}\" does not follow our conventions

               ## Details
               - Check [PR Conventions](#{CONVENTIONS_URL})
               - Allowed tags: `build`, `chore`, `ci`, `docs`, `feat`, `fix`, `perf`, `refactor`, `revert`, `style`, `test`
            """
        end

        target = title.split("(")[1].split(")").first

        if is_capitalized?(target[0])
            description = title.split(":")[1].strip

            if is_capitalized?(description[0])
                return "- The description **'#{description}'** should not have the first letter capitalized."
            end
        else
            return "- The target **'#{target}'** should have the first letter capitalized."
        end

        return nil
    end

    title_error = find_title_error(github.pr_title.to_s)
    if title_error == nil
        message "Congrats! The PR does follow [PR Conventions](#{CONVENTIONS_URL}) :)"
    else
        fail title_error
    end
end

def validate_title_links
    def valid_title_clubhouse_card?(title)
        # [ch-<number>]
        clubhouse_regex = /(\[ch-)(\d)*(\])/
        shortcut_regex = /(\[sc-)(\d)*(\])/

        result = title =~ clubhouse_regex || title =~ shortcut_regex

        result != nil
    end

    pr_title = github.pr_title.to_s

    if !valid_title_clubhouse_card?(pr_title)
        warn "This PR title does not have the clubhouse card id (format: [ch-<number>])"
    end
end

def warn_changed_lines_count
  lines_count = git.lines_of_code

  if lines_count > 140
    link = "https://docs.velocity.codeclimate.com/en/articles/2913568-pull-request-size"
    warn "This PR **looks pretty big**, it modifies #{lines_count} lines of code and top performant teams handle that in less than 140 lines per PR ([Velocity Docs](link))."
  else
    message "Congrats! This PR **is small**! it modifies #{lines_count} lines of code."
  end
end

message "Welcome #{github.pr_author}. Check the [PR Conventions](#{CONVENTIONS_URL}) :)"
validate_title_format
validate_title_links
warn_changed_lines_count