multiple_comparison_spec.rb

# frozen_string_literal: true

RSpec.describe RuboCop::Cop::Style::MultipleComparison do
  subject(:cop) { described_class.new(config) }

  let(:config) { RuboCop::Config.new }

  it 'does not register an offense for comparing an lvar' do
    expect_no_offenses(<<~RUBY)
      a = "a"
      if a == "a"
        print a
      end
    RUBY
  end

  it 'registers an offense and corrects when `a` is compared twice' do
    expect_offense(<<~RUBY)
      a = "a"
      if a == "a" || a == "b"
         ^^^^^^^^^^^^^^^^^^^^ Avoid comparing a variable with multiple items in a conditional, use `Array#include?` instead.
        print a
      end
    RUBY

    expect_correction(<<~RUBY)
      a = "a"
      if ["a", "b"].include?(a)
        print a
      end
    RUBY
  end

  it 'registers an offense and corrects when `a` is compared three times' do
    expect_offense(<<~RUBY)
      a = "a"
      if a == "a" || a == "b" || a == "c"
         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Avoid comparing a variable with multiple items in a conditional, use `Array#include?` instead.
        print a
      end
    RUBY

    expect_correction(<<~RUBY)
      a = "a"
      if ["a", "b", "c"].include?(a)
        print a
      end
    RUBY
  end

  it 'registers an offense and corrects when `a` is compared three times on the right ' \
    'hand side' do
    expect_offense(<<~RUBY)
      a = "a"
      if "a" == a || "b" == a || "c" == a
         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Avoid comparing a variable with multiple items in a conditional, use `Array#include?` instead.
        print a
      end
    RUBY

    expect_correction(<<~RUBY)
      a = "a"
      if ["a", "b", "c"].include?(a)
        print a
      end
    RUBY
  end

  it 'registers an offense and corrects when `a` is compared three times, once on the ' \
    'righthand side' do
    expect_offense(<<~RUBY)
      a = "a"
      if a == "a" || "b" == a || a == "c"
         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Avoid comparing a variable with multiple items in a conditional, use `Array#include?` instead.
        print a
      end
    RUBY

    expect_correction(<<~RUBY)
      a = "a"
      if ["a", "b", "c"].include?(a)
        print a
      end
    RUBY
  end

  it 'registers an offense and corrects when multiple comparison is not ' \
     'part of a conditional' do
    expect_offense(<<~RUBY)
      def foo(x)
        x == 1 || x == 2 || x == 3
        ^^^^^^^^^^^^^^^^^^^^^^^^^^ Avoid comparing a variable with multiple items in a conditional, use `Array#include?` instead.
      end
    RUBY

    expect_correction(<<~RUBY)
      def foo(x)
        [1, 2, 3].include?(x)
      end
    RUBY
  end

  it 'does not register an offense and corrects when using multiple method calls' do
    expect_no_offenses(<<~RUBY)
      col = loc.column
      if col == before.column || col == after.column
        do_something
      end
    RUBY
  end

  it 'does not register an offense for comparing multiple literal strings' do
    expect_no_offenses(<<~RUBY)
      if "a" == "a" || "a" == "c"
        print "a"
      end
    RUBY
  end

  it 'does not register an offense for comparing multiple int literals' do
    expect_no_offenses(<<~RUBY)
      if 1 == 1 || 1 == 2
        print 1
      end
    RUBY
  end

  it 'does not register an offense for comparing lvars' do
    expect_no_offenses(<<~RUBY)
      a = "a"
      b = "b"
      if a == "a" || b == "b"
        print a
      end
    RUBY
  end

  it 'does not register an offense for comparing lvars when a string is ' \
    'on the lefthand side' do
    expect_no_offenses(<<~RUBY)
      a = "a"
      b = "b"
      if a == "a" || "b" == b
        print a
      end
    RUBY
  end

  it 'does not register an offense for a == b || b == a' do
    expect_no_offenses(<<~RUBY)
      a = "a"
      b = "b"
      if a == b || b == a
        print a
      end
    RUBY
  end

  it 'does not register an offense for a duplicated condition' do
    expect_no_offenses(<<~RUBY)
      a = "a"
      b = "b"
      if a == b || a == b
        print a
      end
    RUBY
  end

  it 'does not register an offense for Array#include?' do
    expect_no_offenses(<<~RUBY)
      a = "a"
      if ["a", "b", "c"].include? a
        print a
      end
    RUBY
  end
end