Demonstrates how to have a custom DangerFile that gets the lines of code changed excluding a certain file.

Dangerfile

# If you want to include deletions, `+ git.deleted_files`
modifiedOrNewFiles = (git.added_files + git.modified_files)

diffWithoutPackageLock = modifiedOrNewFiles.select { |file|
    file != "package-lock.json"
}.map { |file|
    git.info_for_file(file)
}.map { |info|
    info[:insertions] + info[:deletions]
}.sum()

warn "Please consider breaking up this PR." if diffWithoutPackageLock > 500