https://github.com/rails/rails/issues/11957

primary_key_uuid.rb

# OPEN ISSUE: https://github.com/rails/rails/issues/11957
# ActiveRecord does not validate the format of a UUID before
# sending a query to the database. Postgres throws an error.
# Preferably, this would raise AR::RecordNotFound.
# 
# ActiveRecord::StatementInvalid:
#   PG::InvalidTextRepresentation: ERROR:  invalid input syntax for uuid: "not-a-uuid"
#
module PrimaryKeyUUID
  # https://github.com/assaf/uuid/blob/1fc6dd2e3a3401aa5bce7cebd57d4af89da9ccd6/lib/uuid.rb#L196-L203
  VALID_DEFAULT = /\A(urn:uuid:)?[\da-f]{8}-([\da-f]{4}-){3}[\da-f]{12}\z/i.freeze
  VALID_COMPACT = /\A[\da-f]{32}\z/i.freeze

  # Use regexps from the 'uuid' gem to
  # determine whether to send the query to the db.
  # Raises AR::RecordNotFound if the given id is 
  # not a valid uuid. Also saves a db query.
  def find(*ids, &block)
    if _valid_uuids?(*ids)
      super
    else
      none.find(*ids, &block)
    end
  end

  private

  def _valid_uuids?(*ids)
    ids.flatten.select do |id|
      PrimaryKeyUUID::VALID_DEFAULT === id || PrimaryKeyUUID::VALID_COMPACT === id
    end.uniq
  end
end