require 'spec_helper' describe Snapshot do let(:snapshot) { described_class.build(data) } let(:data) { [ [['a', fg: 1], ['b', fg: 2]], [['ab', fg: 3] ], [['a', fg: 5], ['b', fg: 6]], [[' ', {}] , ['' , {}]] ] } describe '#thumbnail' do let(:thumbnail) { snapshot.thumbnail(1, 2) } it 'returns a thumbnail of requested width' do expect(thumbnail.width).to eq(1) end it 'returns a thumbnail of requested height' do expect(thumbnail.height).to eq(2) end it 'crops the grid at the bottom left corner' do expect(thumbnail.as_json).to eq([ [['a', fg: 3]], [['a', fg: 5]] ]) end end end