# encoding: utf-8

require 'spec_helper'

describe RuboCop::Cop::Lint::UselessSetterCall do
  subject(:cop) { described_class.new }

  context 'with method ending with setter call on local object' do
    it 'registers an offense' do
      inspect_source(cop,
                     ['def test',
                      '  top = Top.new',
                      '  top.attr = 5',
                      'end'
                     ])
      expect(cop.offenses.size).to eq(1)
      expect(cop.messages)
        .to eq(['Useless setter call to local variable `top`.'])
    end
  end

  context 'with singleton method ending with setter call on local object' do
    it 'registers an offense' do
      inspect_source(cop,
                     ['def Top.test',
                      '  top = Top.new',
                      '  top.attr = 5',
                      'end'
                     ])
      expect(cop.offenses.size).to eq(1)
    end
  end

  context 'with method ending with square bracket setter on local object' do
    it 'registers an offense' do
      inspect_source(cop,
                     ['def test',
                      '  top = Top.new',
                      '  top[:attr] = 5',
                      'end'
                     ])
      expect(cop.offenses.size).to eq(1)
      expect(cop.messages)
        .to eq(['Useless setter call to local variable `top`.'])
    end
  end

  context 'with method ending with ivar assignment' do
    it 'accepts' do
      inspect_source(cop,
                     ['def test',
                      '  something',
                      '  @top = 5',
                      'end'
                     ])
      expect(cop.offenses).to be_empty
    end
  end

  context 'with method ending with setter call on ivar' do
    it 'accepts' do
      inspect_source(cop,
                     ['def test',
                      '  something',
                      '  @top.attr = 5',
                      'end'
                     ])
      expect(cop.offenses).to be_empty
    end
  end

  context 'with method ending with setter call on argument' do
    it 'accepts' do
      inspect_source(cop,
                     ['def test(some_arg)',
                      '  unrelated_local_variable = Top.new',
                      '  some_arg.attr = 5',
                      'end'
                     ])
      expect(cop.offenses).to be_empty
    end
  end

  context 'when a lvar contains an object passed as argument ' \
          'at the end of the method' do
    it 'accepts the setter call on the lvar' do
      inspect_source(cop,
                     ['def test(some_arg)',
                      '  @some_ivar = some_arg',
                      '  @some_ivar.do_something',
                      '  some_lvar = @some_ivar',
                      '  some_lvar.do_something',
                      '  some_lvar.attr = 5',
                      'end'
                     ])
      expect(cop.offenses).to be_empty
    end
  end

  context 'when a lvar contains an object passed as argument ' \
          'by multiple-assignment at the end of the method' do
    it 'accepts the setter call on the lvar' do
      inspect_source(cop,
                     ['def test(some_arg)',
                      '  _first, some_lvar, _third  = 1, some_arg, 3',
                      '  some_lvar.attr = 5',
                      'end'
                     ])
      expect(cop.offenses).to be_empty
    end
  end

  context 'when a lvar does not contain any object passed as argument ' \
          'with multiple-assignment at the end of the method' do
    it 'registers an offense' do
      inspect_source(cop,
                     ['def test(some_arg)',
                      '  _first, some_lvar, _third  = do_something',
                      '  some_lvar.attr = 5',
                      'end'
                     ])
      expect(cop.offenses.size).to eq(1)
    end
  end

  context 'when a lvar possibly contains an object passed as argument ' \
          'by logical-operator-assignment at the end of the method' do
    it 'accepts the setter call on the lvar' do
      inspect_source(cop,
                     ['def test(some_arg)',
                      '  some_lvar = nil',
                      '  some_lvar ||= some_arg',
                      '  some_lvar.attr = 5',
                      'end'
                     ])
      expect(cop.offenses).to be_empty
    end
  end

  context 'when a lvar does not contain any object passed as argument ' \
          'by binary-operator-assignment at the end of the method' do
    it 'registers an offense' do
      inspect_source(cop,
                     ['def test(some_arg)',
                      '  some_lvar = some_arg',
                      '  some_lvar += some_arg',
                      '  some_lvar.attr = 5',
                      'end'
                     ])
      expect(cop.offenses.size).to eq(1)
    end
  end

  context 'when a lvar declared as an argument ' \
          'is no longer the passed object at the end of the method' do
    it 'registers an offense for the setter call on the lvar' do
      inspect_source(cop,
                     ['def test(some_arg)',
                      '  some_arg = Top.new',
                      '  some_arg.attr = 5',
                      'end'
                     ])
      expect(cop.offenses.size).to eq(1)
    end
  end

  context 'when a lvar contains a local object instanciated with literal' do
    it 'registers an offense for the setter call on the lvar' do
      inspect_source(cop,
                     ['def test',
                      '  some_arg = {}',
                      '  some_arg[:attr] = 1',
                      'end'
                     ])
      expect(cop.offenses.size).to eq(1)
    end
  end

  context 'when a lvar contains a non-local object returned by a method' do
    it 'accepts' do
      inspect_source(cop,
                     ['def test',
                      '  some_lvar = Foo.shared_object',
                      '  some_lvar[:attr] = 1',
                      'end'
                     ])
      expect(cop.offenses).to be_empty
    end
  end

  it 'is not confused by operators ending with =' do
    inspect_source(cop,
                   ['def test',
                    '  top.attr == 5',
                    'end'
                   ])
    expect(cop.offenses).to be_empty
  end
end