trailing_comma_in_block_args_spec.rb

# frozen_string_literal: true

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

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

  context 'curly brace block format' do
    it 'registers an offense when a trailing comma is not needed' do
      expect_offense(<<~RUBY)
        test { |a, b,| a + b }
                    ^ Useless trailing comma present in block arguments.
      RUBY
      expect_correction(<<~RUBY)
        test { |a, b| a + b }
      RUBY
    end

    it 'does not register an offense when a trailing comma is required' do
      expect_no_offenses(<<~RUBY)
        test { |a,| a }
      RUBY
    end

    it 'does not register an offense when no arguments are present' do
      expect_no_offenses(<<~RUBY)
        test { a }
      RUBY
    end

    it 'does not register an offense when more than one argument is ' \
       'present with no trailing comma' do
      expect_no_offenses(<<~RUBY)
        test { |a, b| a + b }
      RUBY
    end

    it 'does not register an offense for default arguments' do
      expect_no_offenses(<<~RUBY)
        test { |a, b, c = nil| a + b + c }
      RUBY
    end

    it 'does not register an offense for keyword arguments' do
      expect_no_offenses(<<~RUBY)
        test { |a, b, c: 1| a + b + c }
      RUBY
    end

    it 'ignores commas in default argument strings' do
      expect_no_offenses(<<~RUBY)
        add { |foo, bar = ','| foo + bar }
      RUBY
    end

    it 'preserves semicolons in block/local variables' do
      expect_no_offenses(<<~RUBY)
        add { |foo, bar,; baz| foo + bar }
      RUBY
    end
  end

  context 'do/end block format' do
    it 'registers an offense when a trailing comma is not needed' do
      expect_offense(<<~RUBY)
        test do |a, b,|
                     ^ Useless trailing comma present in block arguments.
          a + b 
        end
      RUBY
      expect_correction(<<~RUBY)
        test do |a, b|
          a + b 
        end
      RUBY
    end

    it 'does not register an offense when a trailing comma is required' do
      expect_no_offenses(<<~RUBY)
        test do |a,|
          a 
        end
      RUBY
    end

    it 'does not register an offense when no arguments are present' do
      expect_no_offenses(<<~RUBY)
        test do
          a 
        end
      RUBY
    end

    it 'does not register an offense for an empty block' do
      expect_no_offenses(<<~RUBY)
        test do ||
        end
      RUBY
    end

    it 'does not register an offense when more than one argument is ' \
       'present with no trailing comma' do
      expect_no_offenses(<<~RUBY)
        test do |a, b|
          a + b
        end
      RUBY
    end

    it 'does not register an offense for default arguments' do
      expect_no_offenses(<<~RUBY)
        test do |a, b, c = nil|
           a + b + c
        end
      RUBY
    end

    it 'does not register an offense for keyword arguments' do
      expect_no_offenses(<<~RUBY)
        test do |a, b, c: 1|
           a + b + c
        end
      RUBY
    end

    it 'ignores commas in default argument strings' do
      expect_no_offenses(<<~RUBY)
        add do |foo, bar = ','| 
          foo + bar 
        end
      RUBY
    end

    it 'preserves semicolons in block/local variables' do
      expect_no_offenses(<<~RUBY)
        add do |foo, bar,; baz| 
          foo + bar
        end
      RUBY
    end
  end
end