require_relative '../../spec_helper'
require_relative '../../../lib/reek/smells/utility_function'
require_relative '../../../lib/reek/examiner'
require_relative 'smell_detector_shared'

RSpec.describe Reek::Smells::UtilityFunction do
  describe 'a detector' do
    let(:detector) { build(:smell_detector, smell_type: :UtilityFunction, source: source_name) }
    let(:source_name) { 'string' }

    it_should_behave_like 'SmellDetector'

    context 'when a smells is reported' do
      let(:warning) do
        src = <<-EOS
          def simple(arga)
            arga.b.c
          end
        EOS
        Reek::Examiner.new(src, ['UtilityFunction']).smells[0]
      end

      it_should_behave_like 'common fields set correctly'

      it 'reports the line number of the method' do
        expect(warning.lines).to eq([1])
      end
    end
  end

  context 'with a singleton method' do
    ['self', 'local_call', '$global'].each do |receiver|
      it 'ignores the receiver' do
        src = "def #{receiver}.simple(arga) arga.to_s + arga.to_i end"
        expect(src).not_to reek_of(:UtilityFunction)
      end
    end
  end

  context 'Singleton methods' do
    it 'for classes with `class << self` notation should not report UtilityFunction' do
      src = 'class C; class << self; def m(a) a.to_s; end; end; end'
      expect(src).not_to reek_of(:UtilityFunction)
    end

    it 'for classes with `self.` notation should not report UtilityFunction' do
      src = 'class C; def self.m(a) a.to_s; end; end'
      expect(src).not_to reek_of(:UtilityFunction)
    end

    it 'for modules with `class << self` notation should not report UtilityFunction' do
      src = 'module M; class << self; def self.m(a) a.to_s; end; end; end'
      expect(src).not_to reek_of(:UtilityFunction)
    end

    it 'for modules with `self.` notation should not report UtilityFunction' do
      src = 'module M; def self.simple(a) a.to_s; end; end'
      expect(src).not_to reek_of(:UtilityFunction)
    end

    context 'by using `module_function`' do
      it 'should not report UtilityFunction' do
        src = 'class C; def m(a) a.to_s; end; module_function :m; end'
        expect(src).not_to reek_of(:UtilityFunction)
      end

      it 'should not report UtilityFunction also when using multiple arguments' do
        src = <<-EOS
          class C
            def m1(a) a.to_s; end
            def m2(a) a.to_s; end
            module_function :m1, :m2
          end
          EOS
        expect(src).not_to reek_of(:UtilityFunction)
      end

      it 'does not report module functions defined by earlier modifier' do
        src = <<-EOF
          module M
            module_function
            def simple(a) a.to_s; end
          end
        EOF
        expect(src).not_to reek_of(:UtilityFunction)
      end

      it 'reports functions preceded by canceled modifier' do
        src = <<-EOF
          module M
            module_function
            public
            def simple(a) a.to_s; end
          end
        EOF
        expect(src).to reek_of(:UtilityFunction)
      end

      it 'does not report when module_function is called in separate scope' do
        src = <<-EOF
          class C
            def m(a) a.to_s; end
            begin
              module_function :m
            end
          end
        EOF
        expect(src).not_to reek_of(:UtilityFunction)
      end

      it 'does not report when module_function modifier is called in separate scope' do
        src = <<-EOF
          class C
            begin
              module_function
            end
            def m(a) a.to_s; end
          end
        EOF
        expect(src).not_to reek_of(:UtilityFunction)
      end
    end
  end

  context 'with no calls' do
    it 'does not report empty method' do
      expect('def simple(arga) end').not_to reek_of(:UtilityFunction)
    end

    it 'does not report literal' do
      expect('def simple() 3; end').not_to reek_of(:UtilityFunction)
    end

    it 'does not report instance variable reference' do
      expect('def simple() @yellow end').not_to reek_of(:UtilityFunction)
    end

    it 'does not report vcall' do
      expect('def simple() y end').not_to reek_of(:UtilityFunction)
    end

    it 'does not report references to self' do
      expect('def into; self; end').not_to reek_of(:UtilityFunction)
    end

    it 'recognises an ivar reference within a block' do
      expect('def clean(text) text.each { @fred = 3} end').not_to reek_of(:UtilityFunction)
    end

    it 'copes with nil superclass' do
      expect('class Object; def is_maybe?() false end end').not_to reek_of(:UtilityFunction)
    end
  end

  context 'with only one call' do
    it 'reports a call to a parameter' do
      expect('def simple(arga) arga.to_s end').to reek_of(:UtilityFunction, name: 'simple')
    end

    it 'reports a call to a constant' do
      expect('def simple(arga) FIELDS[arga] end').to reek_of(:UtilityFunction)
    end
  end

  context 'with two or more calls' do
    it 'reports two calls' do
      src = 'def simple(arga) arga.to_s + arga.to_i end'
      expect(src).to reek_of(:UtilityFunction, name: 'simple')
      expect(src).not_to reek_of(:FeatureEnvy)
    end

    it 'counts a local call in a param initializer' do
      expect('def simple(arga=local) arga.to_s end').not_to reek_of(:UtilityFunction)
    end

    it 'should count usages of self'do
      expect('def <=>(other) Options[:sort_order].compare(self, other) end').
        not_to reek_of(:UtilityFunction)
    end

    it 'should count self reference within a dstr' do
      expect('def as(alias_name); "#{self} as #{alias_name}".to_sym; end').
        not_to reek_of(:UtilityFunction)
    end

    it 'should count calls to self within a dstr' do
      expect('def to_sql; "\'#{self.gsub(/\'/, "\'\'")}\'"; end').
        not_to reek_of(:UtilityFunction)
    end

    it 'should report message chain' do
      src = 'def simple(arga) arga.b.c end'
      expect(src).to reek_of(:UtilityFunction, name: 'simple')
      expect(src).not_to reek_of(:FeatureEnvy)
    end

    it 'does not report a method that calls super' do
      expect('def child(arg) super; arg.to_s; end').not_to reek_of(:UtilityFunction)
    end

    it 'should recognise a deep call' do
      src = <<-EOS
        class Red
          def deep(text)
            text.each { |mod| atts = shelve(mod) }
          end

          def shelve(val)
            @shelf << val
          end
        end
      EOS
      expect(src).not_to reek_of(:UtilityFunction)
    end
  end
end