def test_add_contact_four_letters():
'''
When a contact that is four letters long is added,
the last edge should have a prefix total = 1 and one edge
'''
from trie import vertex, add_contact
new_trie = vertex()
add_contact(new_trie, 'abcd')
# first letter = 'a'
assert new_trie.edges[0] is not None
# first letter = 'ab'
assert new_trie.edges[0].edges[1] is not None
# first letter = 'abc'
assert new_trie.edges[0].edges[1].edges[2] is not None
# first letter = 'abcd'
assert new_trie.edges[0].edges[1].edges[2].edges[3] is not None
# There is one partial that starts with 'a'
assert new_trie.edges[0].partials == 1
# There is 1 partial that is 'ab'
assert new_trie.edges[0].edges[1].partials == 1
# There is 1 partial that is 'abc'
assert new_trie.edges[0].edges[1].edges[2].partials == 1
# There is 1 partial that is 'abcd'
assert new_trie.edges[0].edges[1].edges[2].edges[3].partials == 1
def test_count_partials_one_letter_once():
'''
Count how many contacts that start with 'a' if one 'a' is inserted
'''
from trie import vertex, add_contact, count_partials
new_trie = vertex()
add_contact(new_trie, 'a')
assert count_partials(new_trie, 'a') == 1
def test_add_contact_one_letter():
'''
When a contact that is one letter long is added,
the edge should have a prefix total = 1 and one edge
'''
from trie import vertex, add_contact
new_trie = vertex()
add_contact(new_trie, 'a')
# first (null) vertex
assert new_trie.partials == 1
# first letter = a
assert new_trie.edges[0] is not None
# first letter != b
assert new_trie.edges[1] is None
# There is one partial = 'a'
assert new_trie.edges[0].partials == 1
def test_add_three_contacts_four_letters():
'''
When three overlapping contact that is four letters long is added,
the last edge should have a prefix total = 1 and one edge
'''
from trie import vertex, add_contact
new_trie = vertex()
add_contact(new_trie, 'abcd')
add_contact(new_trie, 'abde')
add_contact(new_trie, 'acde')
# There are 3 partials that starts with 'a'
assert new_trie.edges[0].partials == 3
# There are 2 partials that is 'ab'
assert new_trie.edges[0].edges[1].partials == 2
# There is 1 partial that is 'ac'
assert new_trie.edges[0].edges[2].partials == 1
# There is 1 partial that is 'abcd'
assert new_trie.edges[0].edges[1].edges[2].edges[3].partials == 1
# There is 1 partial that is 'abde'
assert new_trie.edges[0].edges[1].edges[3].edges[4].partials == 1
# There is 1 partial that is 'acde'
assert new_trie.edges[0].edges[2].edges[3].edges[4].partials == 1
def test_count_partials_three_letter_many_words():
'''
Count how many contacts that start with 'abc' if many different
contacts starting with 'abc' are inserted
'''
from trie import vertex, add_contact, count_partials
new_trie = vertex()
add_contact(new_trie, 'abc')
add_contact(new_trie, 'abcsdf')
add_contact(new_trie, 'abcrt')
add_contact(new_trie, 'abcttt')
assert count_partials(new_trie, 'a') == 4