redundant_freeze_spec.rb

# frozen_string_literal: true

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

  let(:prefix) { nil }

  shared_examples 'immutable objects' do |o|
    it "registers an offense for frozen #{o}" do
      source = [prefix, "CONST = #{o}.freeze"].compact.join("\n")
      inspect_source(source)
      expect(cop.offenses.size).to eq(1)
    end

    it 'auto-corrects by removing .freeze' do
      source = [prefix, "CONST = #{o}.freeze"].compact.join("\n")
      new_source = autocorrect_source(source)
      expect(new_source).to eq(source.chomp('.freeze'))
    end
  end

  it_behaves_like 'immutable objects', '1'
  it_behaves_like 'immutable objects', '1.5'
  it_behaves_like 'immutable objects', ':sym'
  it_behaves_like 'immutable objects', ':""'
  it_behaves_like 'immutable objects', "ENV['foo']"
  it_behaves_like 'immutable objects', "'foo'.count"
  it_behaves_like 'immutable objects', '(1 + 2)'
  it_behaves_like 'immutable objects', '(2 > 1)'
  it_behaves_like 'immutable objects', "('a' > 'b')"
  it_behaves_like 'immutable objects', '(a > b)'
  it_behaves_like 'immutable objects', '[1, 2, 3].size'

  shared_examples 'mutable objects' do |o|
    it "allows #{o} with freeze" do
      source = [prefix, "CONST = #{o}.freeze"].compact.join("\n")
      expect_no_offenses(source)
    end
  end

  it_behaves_like 'mutable objects', '[1, 2, 3]'
  it_behaves_like 'mutable objects', '{ a: 1, b: 2 }'
  it_behaves_like 'mutable objects', "'str'"
  it_behaves_like 'mutable objects', '"top#{1 + 2}"'
  it_behaves_like 'mutable objects', '/./'
  it_behaves_like 'mutable objects', '(1..5)'
  it_behaves_like 'mutable objects', '(1...5)'
  it_behaves_like 'mutable objects', "('a' + 'b')"
  it_behaves_like 'mutable objects', "('a' * 20)"
  it_behaves_like 'mutable objects', '(a + b)'

  it 'allows .freeze on  method call' do
    expect_no_offenses('TOP_TEST = Something.new.freeze')
  end

  context 'when the receiver is a frozen string literal' do
    if RuboCop::Config::KNOWN_RUBIES.include?(3.0)
      context 'when the target ruby version >= 3.0' do
        let(:ruby_version) { 3.0 }

        context 'when the frozen string literal comment is missing' do
          it_behaves_like 'immutable objects', '"#{a}"'
        end

        context 'when the frozen string literal comment is true' do
          let(:prefix) { '# frozen_string_literal: true' }

          it_behaves_like 'immutable objects', '"#{a}"'
        end

        context 'when the frozen string literal comment is false' do
          let(:prefix) { '# frozen_string_literal: false' }

          it_behaves_like 'immutable objects', '"#{a}"'
        end
      end
    end

    context 'when the target ruby version >= 2.3' do
      let(:ruby_version) { 2.3 }

      context 'when the frozen string literal comment is missing' do
        it_behaves_like 'mutable objects', '"#{a}"'
      end

      context 'when the frozen string literal comment is true' do
        let(:prefix) { '# frozen_string_literal: true' }

        it_behaves_like 'immutable objects', '"#{a}"'
      end

      context 'when the frozen string literal comment is false' do
        let(:prefix) { '# frozen_string_literal: false' }

        it_behaves_like 'mutable objects', '"#{a}"'
      end
    end
  end
end