Method: Mongo::Lint.validate_read_concern_option

Defined in:
lib/mongo/lint.rb

.validate_read_concern_option(read_concern) ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Validates the provided hash as a read concern object, per the read/write concern specification (github.com/mongodb/specifications/blob/master/source/read-write-concern/read-write-concern.md#read-concern).

This method also accepts nil as input for convenience.

The read concern document as sent to the server may include additional fields, for example afterClusterTime. These fields are generated internally by the driver and cannot be specified by the user (and would potentially lead to incorrect behavior if they were specified by the user), hence this method prohibits them.

Parameters:

  • read_concern (Hash) —

    The read concern options hash, with the following optional keys:

    • :level – the read preference level as a symbol; valid values

      are *:local*, *:majority*, and *:snapshot*

Raises:



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# File 'lib/mongo/lint.rb', line 76

def validate_read_concern_option(read_concern)
  return unless enabled?
  return if read_concern.nil?
  unless read_concern.is_a?(Hash)
    raise Error::LintError, "Read concern is not a hash: #{read_concern}"
  end
  return if read_concern.empty?
  keys = read_concern.keys
  if read_concern.is_a?(BSON::Document)
    # Permits indifferent access
    allowed_keys = ['level']
  else
    # Does not permit indifferent access
    allowed_keys = [:level]
  end
  if keys != allowed_keys
    raise Error::LintError, "Read concern has invalid keys: #{keys.inspect}"
  end
  level = read_concern[:level]
  return if [:local, :available, :majority, :linearizable, :snapshot].include?(level)
  raise Error::LintError, "Read concern level is invalid: value must be a symbol: #{level.inspect}"
end