Class: RuboCop::Cop::GraphQL::Overfetch

Inherits:
RuboCop::Cop show all
Defined in:
lib/rubocop/cop/graphql/overfetch.rb

Overview

Public: Rubocop for catching overfetched fields in ERB templates.

Instance Method Summary collapse

Instance Method Details

#field_aliases(name) ⇒ Object 



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# File 'lib/rubocop/cop/graphql/overfetch.rb', line 48

def field_aliases(name)
  names = Set.new

  names << name
  names << "#{name}?"

  names << underscore_name = ActiveSupport::Inflector.underscore(name)
  names << "#{underscore_name}?"

  names
end

#investigate(processed_source) ⇒ Object 



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# File 'lib/rubocop/cop/graphql/overfetch.rb', line 14

def investigate(processed_source)
  erb = File.read(processed_source.buffer.name)
  query, = ::GraphQL::Client::Erubis.extract_graphql_section(erb)
  return unless query

  aliases = {}
  fields = {}
  ranges = {}

  # TODO: Use GraphQL client parser
  document = ::GraphQL.parse(query.gsub(/::/, "__"))

  visitor = ::GraphQL::Language::Visitor.new(document)
  visitor[::GraphQL::Language::Nodes::Field] << ->(node, _parent) do
    name = node.alias || node.name
    fields[name] ||= 0
    field_aliases(name).each { |n| (aliases[n] ||= []) << name }
    ranges[name] ||= source_range(processed_source.buffer, node.line, 0)
  end
  visitor.visit

  send_methods(processed_source.ast).each do |node|
    _receiver, method_name, *_args = *node
    aliases.fetch(method_name.to_s, []).each do |field_name|
      fields[field_name] += 1
    end
  end

  fields.each do |field, count|
    next if count > 0
    add_offense(nil, ranges[field], "GraphQL field '#{field}' query but was not used in template.")
  end
end