Class: RuboCop::Cop::RSpec::MultipleMemoizedHelpers

Inherits:
Base
  • Object
show all
Includes:
ConfigurableMax, Variable
Defined in:
lib/rubocop/cop/rspec/multiple_memoized_helpers.rb

Overview

Checks if example groups contain too many ‘let` and `subject` calls.

This cop is configurable using the ‘Max` option and the `AllowSubject` which will configure the cop to only register offenses on calls to `let` and not calls to `subject`.

Examples:

# bad
describe MyClass do
  let(:foo) { [] }
  let(:bar) { [] }
  let!(:baz) { [] }
  let(:qux) { [] }
  let(:quux) { [] }
  let(:quuz) { {} }
end

describe MyClass do
  let(:foo) { [] }
  let(:bar) { [] }
  let!(:baz) { [] }

  context 'when stuff' do
    let(:qux) { [] }
    let(:quux) { [] }
    let(:quuz) { {} }
  end
end

# good
describe MyClass do
  let(:bar) { [] }
  let!(:baz) { [] }
  let(:qux) { [] }
  let(:quux) { [] }
  let(:quuz) { {} }
end

describe MyClass do
  context 'when stuff' do
    let(:foo) { [] }
    let(:bar) { [] }
    let!(:booger) { [] }
  end

  context 'when other stuff' do
    let(:qux) { [] }
    let(:quux) { [] }
    let(:quuz) { {} }
  end
end

when disabling AllowSubject configuration


# rubocop.yml
# RSpec/MultipleMemoizedHelpers:
#   AllowSubject: false

# bad - `subject` counts towards memoized helpers
describe MyClass do
  subject { {} }
  let(:foo) { [] }
  let(:bar) { [] }
  let!(:baz) { [] }
  let(:qux) { [] }
  let(:quux) { [] }
end

with Max configuration


# rubocop.yml
# RSpec/MultipleMemoizedHelpers:
#   Max: 1

# bad
describe MyClass do
  let(:foo) { [] }
  let(:bar) { [] }
end

Constant Summary collapse

MSG = 
'Example group has too many memoized helpers [%<count>d/%<max>d]'

Constants included from Variable

Variable::Helpers, Variable::Subjects

Instance Method Summary collapse

Methods inherited from Base

inherited

Methods included from RSpec::Language::NodePattern

#block_pattern, #send_pattern

Instance Method Details

#on_block(node) ⇒ Object 



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# File 'lib/rubocop/cop/rspec/multiple_memoized_helpers.rb', line 92

def on_block(node)
  return unless spec_group?(node)

  count = all_helpers(node).uniq.count

  return if count <= max

  self.max = count
  add_offense(node, message: format(MSG, count: count, max: max))
end

#on_new_investigation ⇒ Object 



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# File 'lib/rubocop/cop/rspec/multiple_memoized_helpers.rb', line 103

def on_new_investigation
  super
  @example_group_memoized_helpers = {}
end