Action JS allEntries, "$or" not working in wagon (but does in locomotive)

[proxygear]

In my wagon, in a .liquid file, I tried the following :

{% action 'custom query' %}
allEntries(
  myContentType, 
  {
    '$or': [ condition1, condition2]
  }
)
{% endaction %}

I seams $or is not implemented.

I added to locomotive/steam specs, into spec/unit/services/action_service_spec.rb, the following test. It's a copy of an existing spec named allEntries, but using the $or.

describe 'allEntries with an $or' do
        let(:now)     { Time.use_zone('America/Chicago') { Time.zone.local(2015, 'mar', 25, 10, 0) } }
        let(:assigns) { { 'now' => now } }
        let(:script) {
          <<-JS
            var entries = allEntries('bands', {
              '$or': [
                { featured: true },
                { leader: 'Eddie'}
              ]
            });
            var names = []

            for (var i = 0; i < entries.length; i++) {
              names.push(entries[i].name)
            }

            return names.join(', ')
          JS
        }

        before do
          expect(entry_service).to(
            receive(:all)
              .with(
                'bands',
                {
                  '$or' => [
                    { 'featured' => true },
                    { 'leader' => 'Eddie' }
                  ]
                },
                true
              )
              .and_return(
                [
                  { 'name' => 'Pearl Jam' },
                  { 'name' => 'The who' }
                ]
              )
          )
        end

        it { is_expected.to eq('Pearl Jam, The who') }
      end

This spec is passing, so I guess it used the mongoDB backend.

I dug more into steam, finding the lib/locomotive/steam/adapters/memory.rb.
I haven't found any trace of the $or in there.
I haven't been able to understand enough the spec/unit/adapters/memory_adapter_spec.rb and it's sub files to write a failing test for the or operator.