# test_isolate.py - unit tests for the isolate module
#
# Copyright 2015 NetworkX developers.
#
# This file is part of NetworkX.
#
# NetworkX is distributed under a BSD license; see LICENSE.txt for more
# information.
"""Unit tests for the :mod:`networkx.algorithms.isolates` module."""
from nose.tools import assert_equal
from nose.tools import assert_false
from nose.tools import assert_true

import networkx as nx


def test_is_isolate():
    G = nx.Graph()
    G.add_edge(0, 1)
    G.add_node(2)
    assert_false(nx.is_isolate(G, 0))
    assert_false(nx.is_isolate(G, 1))
    assert_true(nx.is_isolate(G, 2))


def test_isolates():
    G = nx.Graph()
    G.add_edge(0, 1)
    G.add_nodes_from([2, 3])
    assert_equal(sorted(nx.isolates(G)), [2, 3])


def test_number_of_isolates():
    G = nx.Graph()
    G.add_edge(0, 1)
    G.add_nodes_from([2, 3])
    assert_equal(nx.number_of_isolates(G), 2)