76 lines
2.5 KiB
Ruby
76 lines
2.5 KiB
Ruby
# Copyright (C) 2024 Manuel Bustillo
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# frozen_string_literal: true
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require 'rails_helper'
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module Tree
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RSpec.describe TreeNode do
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describe '#distance_to_common_ancestor' do
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def assert_distance(node1, node2, distance)
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aggregate_failures do
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expect(node1.distance_to_common_ancestor(node2)).to eq(distance)
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expect(node2.distance_to_common_ancestor(node1)).to eq(distance)
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end
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end
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context 'when the two nodes are the same' do
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it 'returns 0 when comparing the root itself' do
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root = described_class.new('root')
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assert_distance(root, root, 0)
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end
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it 'returns 0 when comparing a child to itself' do
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root = described_class.new('root')
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child = root << described_class.new('child')
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assert_distance(child, child, 0)
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end
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end
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context 'when the two nodes are siblings' do
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it 'returns 1 when comparing siblings' do
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root = described_class.new('root')
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child1 = root << described_class.new('child1')
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child2 = root << described_class.new('child2')
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assert_distance(child1, child2, 1)
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end
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end
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context 'when one node is parent of the other' do
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it 'returns 1 when comparing parent to child' do
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root = described_class.new('root')
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child = root << described_class.new('child')
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assert_distance(root, child, 1)
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end
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end
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context 'when one node is grandparent of the other' do
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it 'returns 2 when comparing grandparent to grandchild' do
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root = described_class.new('root')
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child = root << described_class.new('child')
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grandchild = child << described_class.new('grandchild')
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assert_distance(root, grandchild, 2)
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end
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end
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context 'when the two nodes are cousins' do
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it 'returns 2 when comparing cousins' do
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root = described_class.new('root')
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child1 = root << described_class.new('child1')
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child2 = root << described_class.new('child2')
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grandchild1 = child1 << described_class.new('grandchild1')
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grandchild2 = child2 << described_class.new('grandchild2')
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assert_distance(grandchild1, grandchild2, 2)
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end
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end
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context 'when the two nodes are not related' do
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it 'returns nil' do
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root = described_class.new('root')
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another_root = described_class.new('another_root')
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assert_distance(root, another_root, nil)
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end
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end
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end
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end
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end
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