CodeLength incorrectly calculated when there are kwargs that should be counted as one

[Darhazer]

When there are keyword arguments, and the configuration says that hashes should be counted as one line, the code length module calculates the length incorrectly, by always subtracting 2.

I tracked the issue down to the Metrics::Utils::CodeLengthCalculator which includes this line

# Subtract 2 length of opening and closing brace if method argument omits hash braces.
length -= 2 if descendant.hash_type? && !descendant.braces?

This is valid in this example:

foo(
              foo: :bar,
              baz: :quux
            )

But not this one:

foo(foo: :bar, baz: :quux)

As a reproduction spec:

it 'folds hashes as method kwargs if asked' do
        source = parse_source(<<~RUBY)
          def test
            foo(foo: :bar, baz: :quux)
          end
        RUBY

        length = described_class.new(source.ast, source, foldable_types: %i[hash]).calculate
        expect(length).to eq(1)
      end

This gives a result of -1

RuboCop version

Tested on master

$ rubocop -V 
1.26.1 (using Parser 3.1.1.0, rubocop-ast 1.16.0, running on ruby 2.6.8 universal.arm64e-darwin21)
  - rubocop-performance 1.13.3
  - rubocop-rake 0.6.0
  - rubocop-rspec 2.9.0

[Darhazer]

#10520 fixes just a specific case. If the node is multiline, but still starts at the line of the parent node, it still gives the wrong result

it 'folds hashes as method args if asked' do
        source = parse_source(<<~RUBY)
          def test
            foo(foo: :bar,
                baz: :quux)
          end
        RUBY

        length = described_class.new(source.ast, source, foldable_types: %i[hash]).calculate
        expect(length).to eq(1)
      end

The actual of the above is -1

[nobuyo]

I'm sorry for I didn't enough consider about coverage of cases 🙏
I'll attempt some additional fix on new branch.

Do the following examples cover all cases for this issue?

# pattern 1
def test
  foo(
    foo: :bar,
    baz: :quux
  )
end

# pattern 2
def test
  foo(foo: :bar, baz: :quux)
end

# pattern 3
def test
  foo(foo: :bar,
      baz: :quux)
end

# pattern 4
def test
  foo(
    foo: :bar, baz: :quux
  )
end

[Darhazer]

I'm sorry for I didn't enough consider about coverage of cases pray

That's alright - you have improved the calculation nevertheless. Just haven't fully resolved the issue

I'll attempt some additional fix on new branch.

Thank you 🙇

Do the following examples cover all cases for this issue?

Seems exhaustive enough. Well, if you want to go to extremes:

# pattern 5
def test
  foo(
    # those are keyword arguments
    foo: :bar, baz: :quux

  )
end

Though it's not clear whether we should count the comment as part of the hash or not 🤷‍♂️

[nobuyo]

I created PR (#10543) for this. I'd be happy if you take a look at it :)

[Darhazer]

Fixed in #10543