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	# -- coding: utf-8 --
	"""Tests for Beautiful Soup's tree traversal methods.

	The tree traversal methods are the main advantage of using Beautiful
	Soup over just using a parser.

	Different parsers will build different Beautiful Soup trees given the
	same markup, but all Beautiful Soup trees can be traversed with the
	methods tested here.
	"""

	from pdb import set_trace
	import pytest
	import re
	import warnings
	from bs4 import BeautifulSoup
	from bs4.builder import (
	builder_registry,
	HTMLParserTreeBuilder,
	)
	from bs4.element import (
	CData,
	Comment,
	Declaration,
	Doctype,
	Formatter,
	NavigableString,
	Script,
	SoupStrainer,
	Stylesheet,
	Tag,
	TemplateString,
	)
	from . import (
	SoupTest,
	)

	class TestFind(SoupTest):
	"""Basic tests of the find() method.

	find() just calls find_all() with limit=1, so it's not tested all
	that thouroughly here.
	"""

	def test_find_tag(self):
	soup = self.soup("<a>1</a><b>2</b><a>3</a><b>4</b>")
	assert soup.find("b").string == "2"

	def test_unicode_text_find(self):
	soup = self.soup('<h1>Räksmörgås</h1>')
	assert soup.find(string='Räksmörgås') == 'Räksmörgås'

	def test_unicode_attribute_find(self):
	soup = self.soup('<h1 id="Räksmörgås">here it is</h1>')
	str(soup)
	assert "here it is" == soup.find(id='Räksmörgås').text


	def test_find_everything(self):
	"""Test an optimization that finds all tags."""
	soup = self.soup("<a>foo</a><b>bar</b>")
	assert 2 == len(soup.find_all())

	def test_find_everything_with_name(self):
	"""Test an optimization that finds all tags with a given name."""
	soup = self.soup("<a>foo</a><b>bar</b><a>baz</a>")
	assert 2 == len(soup.find_all('a'))

	class TestFindAll(SoupTest):
	"""Basic tests of the find_all() method."""

	def test_find_all_text_nodes(self):
	"""You can search the tree for text nodes."""
	soup = self.soup("<html>Foo<b>bar</b>\xbb</html>")
	# Exact match.
	assert soup.find_all(string="bar") == ["bar"]


	# Match any of a number of strings.
	assert soup.find_all(string=["Foo", "bar"]) == ["Foo", "bar"]
	# Match a regular expression.
	assert soup.find_all(string=re.compile('.*')) == ["Foo", "bar", '\xbb']
	# Match anything.
	assert soup.find_all(string=True) == ["Foo", "bar", '\xbb']

	def test_find_all_limit(self):
	"""You can limit the number of items returned by find_all."""
	soup = self.soup("<a>1</a><a>2</a><a>3</a><a>4</a><a>5</a>")
	self.assert_selects(soup.find_all('a', limit=3), ["1", "2", "3"])
	self.assert_selects(soup.find_all('a', limit=1), ["1"])
	self.assert_selects(
	soup.find_all('a', limit=10), ["1", "2", "3", "4", "5"])

	# A limit of 0 means no limit.
	self.assert_selects(
	soup.find_all('a', limit=0), ["1", "2", "3", "4", "5"])

	def test_calling_a_tag_is_calling_findall(self):
	soup = self.soup("<a>1</a><b>2<a id='foo'>3</a></b>")
	self.assert_selects(soup('a', limit=1), ["1"])
	self.assert_selects(soup.b(id="foo"), ["3"])

	def test_find_all_with_self_referential_data_structure_does_not_cause_infinite_recursion(self):
	soup = self.soup("<a></a>")
	# Create a self-referential list.
	l = []
	l.append(l)

	# Without special code in _normalize_search_value, this would cause infinite
	# recursion.
	assert [] == soup.find_all(l)

	def test_find_all_resultset(self):
	"""All find_all calls return a ResultSet"""
	soup = self.soup("<a></a>")
	result = soup.find_all("a")
	assert hasattr(result, "source")

	result = soup.find_all(True)
	assert hasattr(result, "source")

	result = soup.find_all(string="foo")
	assert hasattr(result, "source")


	class TestFindAllBasicNamespaces(SoupTest):

	def test_find_by_namespaced_name(self):
	soup = self.soup('<mathml:msqrt>4</mathml:msqrt><a svg:fill="red">')
	assert "4" == soup.find("mathml:msqrt").string
	assert "a" == soup.find(attrs= { "svg:fill" : "red" }).name


	class TestFindAllByName(SoupTest):
	"""Test ways of finding tags by tag name."""

	def setup_method(self):
	self.tree = self.soup("""<a>First tag.</a>
	<b>Second tag.</b>
	<c>Third <a>Nested tag.</a> tag.</c>""")

	def test_find_all_by_tag_name(self):
	# Find all the <a> tags.
	self.assert_selects(
	self.tree.find_all('a'), ['First tag.', 'Nested tag.'])

	def test_find_all_by_name_and_text(self):
	self.assert_selects(
	self.tree.find_all('a', string='First tag.'), ['First tag.'])

	self.assert_selects(
	self.tree.find_all('a', string=True), ['First tag.', 'Nested tag.'])

	self.assert_selects(
	self.tree.find_all('a', string=re.compile("tag")),
	['First tag.', 'Nested tag.'])


	def test_find_all_on_non_root_element(self):
	# You can call find_all on any node, not just the root.
	self.assert_selects(self.tree.c.find_all('a'), ['Nested tag.'])

	def test_calling_element_invokes_find_all(self):
	self.assert_selects(self.tree('a'), ['First tag.', 'Nested tag.'])

	def test_find_all_by_tag_strainer(self):
	self.assert_selects(
	self.tree.find_all(SoupStrainer('a')),
	['First tag.', 'Nested tag.'])

	def test_find_all_by_tag_names(self):
	self.assert_selects(
	self.tree.find_all(['a', 'b']),
	['First tag.', 'Second tag.', 'Nested tag.'])

	def test_find_all_by_tag_dict(self):
	self.assert_selects(
	self.tree.find_all({'a' : True, 'b' : True}),
	['First tag.', 'Second tag.', 'Nested tag.'])

	def test_find_all_by_tag_re(self):
	self.assert_selects(
	self.tree.find_all(re.compile('^[ab]$')),
	['First tag.', 'Second tag.', 'Nested tag.'])

	def test_find_all_with_tags_matching_method(self):
	# You can define an oracle method that determines whether
	# a tag matches the search.
	def id_matches_name(tag):
	return tag.name == tag.get('id')

	tree = self.soup("""<a id="a">Match 1.</a>
	<a id="1">Does not match.</a>
	<b id="b">Match 2.</a>""")

	self.assert_selects(
	tree.find_all(id_matches_name), ["Match 1.", "Match 2."])

	def test_find_with_multi_valued_attribute(self):
	soup = self.soup(
	"<div class='a b'>1</div><div class='a c'>2</div><div class='a d'>3</div>"
	)
	r1 = soup.find('div', 'a d');
	r2 = soup.find('div', re.compile(r'a d'));
	r3, r4 = soup.find_all('div', ['a b', 'a d']);
	assert '3' == r1.string
	assert '3' == r2.string
	assert '1' == r3.string
	assert '3' == r4.string


	class TestFindAllByAttribute(SoupTest):

	def test_find_all_by_attribute_name(self):
	# You can pass in keyword arguments to find_all to search by
	# attribute.
	tree = self.soup("""
	<a id="first">Matching a.</a>
	<a id="second">
	Non-matching <b id="first">Matching b.</b>a.
	</a>""")
	self.assert_selects(tree.find_all(id='first'),
	["Matching a.", "Matching b."])

	def test_find_all_by_utf8_attribute_value(self):
	peace = "םולש".encode("utf8")
	data = '<a title="םולש"></a>'.encode("utf8")
	soup = self.soup(data)
	assert [soup.a] == soup.find_all(title=peace)
	assert [soup.a] == soup.find_all(title=peace.decode("utf8"))
	assert [soup.a], soup.find_all(title=[peace, "something else"])

	def test_find_all_by_attribute_dict(self):
	# You can pass in a dictionary as the argument 'attrs'. This
	# lets you search for attributes like 'name' (a fixed argument
	# to find_all) and 'class' (a reserved word in Python.)
	tree = self.soup("""
	<a name="name1" class="class1">Name match.</a>
	<a name="name2" class="class2">Class match.</a>
	<a name="name3" class="class3">Non-match.</a>
	<name1>A tag called 'name1'.</name1>
	""")

	# This doesn't do what you want.
	self.assert_selects(tree.find_all(name='name1'),
	["A tag called 'name1'."])
	# This does what you want.
	self.assert_selects(tree.find_all(attrs={'name' : 'name1'}),
	["Name match."])

	self.assert_selects(tree.find_all(attrs={'class' : 'class2'}),
	["Class match."])

	def test_find_all_by_class(self):
	tree = self.soup("""
	<a class="1">Class 1.</a>
	<a class="2">Class 2.</a>
	<b class="1">Class 1.</b>
	<c class="3 4">Class 3 and 4.</c>
	""")

	# Passing in the class_ keyword argument will search against
	# the 'class' attribute.
	self.assert_selects(tree.find_all('a', class_='1'), ['Class 1.'])
	self.assert_selects(tree.find_all('c', class_='3'), ['Class 3 and 4.'])
	self.assert_selects(tree.find_all('c', class_='4'), ['Class 3 and 4.'])

	# Passing in a string to 'attrs' will also search the CSS class.
	self.assert_selects(tree.find_all('a', '1'), ['Class 1.'])
	self.assert_selects(tree.find_all(attrs='1'), ['Class 1.', 'Class 1.'])
	self.assert_selects(tree.find_all('c', '3'), ['Class 3 and 4.'])
	self.assert_selects(tree.find_all('c', '4'), ['Class 3 and 4.'])

	def test_find_by_class_when_multiple_classes_present(self):
	tree = self.soup("<gar class='foo bar'>Found it</gar>")

	f = tree.find_all("gar", class_=re.compile("o"))
	self.assert_selects(f, ["Found it"])

	f = tree.find_all("gar", class_=re.compile("a"))
	self.assert_selects(f, ["Found it"])

	# If the search fails to match the individual strings "foo" and "bar",
	# it will be tried against the combined string "foo bar".
	f = tree.find_all("gar", class_=re.compile("o b"))
	self.assert_selects(f, ["Found it"])

	def test_find_all_with_non_dictionary_for_attrs_finds_by_class(self):
	soup = self.soup("<a class='bar'>Found it</a>")

	self.assert_selects(soup.find_all("a", re.compile("ba")), ["Found it"])

	def big_attribute_value(value):
	return len(value) > 3

	self.assert_selects(soup.find_all("a", big_attribute_value), [])

	def small_attribute_value(value):
	return len(value) <= 3

	self.assert_selects(
	soup.find_all("a", small_attribute_value), ["Found it"])

	def test_find_all_with_string_for_attrs_finds_multiple_classes(self):
	soup = self.soup('<a class="foo bar"></a><a class="foo"></a>')
	a, a2 = soup.find_all("a")
	assert [a, a2], soup.find_all("a", "foo")
	assert [a], soup.find_all("a", "bar")

	# If you specify the class as a string that contains a
	# space, only that specific value will be found.
	assert [a] == soup.find_all("a", class_="foo bar")
	assert [a] == soup.find_all("a", "foo bar")
	assert [] == soup.find_all("a", "bar foo")

	def test_find_all_by_attribute_soupstrainer(self):
	tree = self.soup("""
	<a id="first">Match.</a>
	<a id="second">Non-match.</a>""")

	strainer = SoupStrainer(attrs={'id' : 'first'})
	self.assert_selects(tree.find_all(strainer), ['Match.'])

	def test_find_all_with_missing_attribute(self):
	# You can pass in None as the value of an attribute to find_all.
	# This will match tags that do not have that attribute set.
	tree = self.soup("""<a id="1">ID present.</a>
	<a>No ID present.</a>
	<a id="">ID is empty.</a>""")
	self.assert_selects(tree.find_all('a', id=None), ["No ID present."])

	def test_find_all_with_defined_attribute(self):
	# You can pass in None as the value of an attribute to find_all.
	# This will match tags that have that attribute set to any value.
	tree = self.soup("""<a id="1">ID present.</a>
	<a>No ID present.</a>
	<a id="">ID is empty.</a>""")
	self.assert_selects(
	tree.find_all(id=True), ["ID present.", "ID is empty."])

	def test_find_all_with_numeric_attribute(self):
	# If you search for a number, it's treated as a string.
	tree = self.soup("""<a id=1>Unquoted attribute.</a>
	<a id="1">Quoted attribute.</a>""")

	expected = ["Unquoted attribute.", "Quoted attribute."]
	self.assert_selects(tree.find_all(id=1), expected)
	self.assert_selects(tree.find_all(id="1"), expected)

	def test_find_all_with_list_attribute_values(self):
	# You can pass a list of attribute values instead of just one,
	# and you'll get tags that match any of the values.
	tree = self.soup("""<a id="1">1</a>
	<a id="2">2</a>
	<a id="3">3</a>
	<a>No ID.</a>""")
	self.assert_selects(tree.find_all(id=["1", "3", "4"]),
	["1", "3"])

	def test_find_all_with_regular_expression_attribute_value(self):
	# You can pass a regular expression as an attribute value, and
	# you'll get tags whose values for that attribute match the
	# regular expression.
	tree = self.soup("""<a id="a">One a.</a>
	<a id="aa">Two as.</a>
	<a id="ab">Mixed as and bs.</a>
	<a id="b">One b.</a>
	<a>No ID.</a>""")

	self.assert_selects(tree.find_all(id=re.compile("^a+$")),
	["One a.", "Two as."])

	def test_find_by_name_and_containing_string(self):
	soup = self.soup("<b>foo</b><b>bar</b><a>foo</a>")
	a = soup.a

	assert [a] == soup.find_all("a", string="foo")
	assert [] == soup.find_all("a", string="bar")

	def test_find_by_name_and_containing_string_when_string_is_buried(self):
	soup = self.soup("<a>foo</a><a><b><c>foo</c></b></a>")
	assert soup.find_all("a") == soup.find_all("a", string="foo")

	def test_find_by_attribute_and_containing_string(self):
	soup = self.soup('<b id="1">foo</b><a id="2">foo</a>')
	a = soup.a

	assert [a] == soup.find_all(id=2, string="foo")
	assert [] == soup.find_all(id=1, string="bar")


	class TestSmooth(SoupTest):
	"""Test Tag.smooth."""

	def test_smooth(self):
	soup = self.soup("<div>a</div>")
	div = soup.div
	div.append("b")
	div.append("c")
	div.append(Comment("Comment 1"))
	div.append(Comment("Comment 2"))
	div.append("d")
	builder = self.default_builder()
	span = Tag(soup, builder, 'span')
	span.append('1')
	span.append('2')
	div.append(span)

	# At this point the tree has a bunch of adjacent
	# NavigableStrings. This is normal, but it has no meaning in
	# terms of HTML, so we may want to smooth things out for
	# output.

	# Since the <span> tag has two children, its .string is None.
	assert None == div.span.string

	assert 7 == len(div.contents)
	div.smooth()
	assert 5 == len(div.contents)

	# The three strings at the beginning of div.contents have been
	# merged into on string.
	#
	assert 'abc' == div.contents[0]

	# The call is recursive -- the <span> tag was also smoothed.
	assert '12' == div.span.string

	# The two comments have _not_ been merged, even though
	# comments are strings. Merging comments would change the
	# meaning of the HTML.
	assert 'Comment 1' == div.contents[1]
	assert 'Comment 2' == div.contents[2]


	class TestIndex(SoupTest):
	"""Test Tag.index"""
	def test_index(self):
	tree = self.soup("""<div>
	<a>Identical</a>
	<b>Not identical</b>
	<a>Identical</a>

	<c><d>Identical with child</d></c>
	<b>Also not identical</b>
	<c><d>Identical with child</d></c>
	</div>""")
	div = tree.div
	for i, element in enumerate(div.contents):
	assert i == div.index(element)
	with pytest.raises(ValueError):
	tree.index(1)


	class TestParentOperations(SoupTest):
	"""Test navigation and searching through an element's parents."""

	def setup_method(self):
	self.tree = self.soup('''<ul id="empty"></ul>
	<ul id="top">
	<ul id="middle">
	<ul id="bottom">
	<b>Start here</b>
	</ul>
	</ul>''')
	self.start = self.tree.b


	def test_parent(self):
	assert self.start.parent['id'] == 'bottom'
	assert self.start.parent.parent['id'] == 'middle'
	assert self.start.parent.parent.parent['id'] == 'top'

	def test_parent_of_top_tag_is_soup_object(self):
	top_tag = self.tree.contents[0]
	assert top_tag.parent == self.tree

	def test_soup_object_has_no_parent(self):
	assert None == self.tree.parent

	def test_find_parents(self):
	self.assert_selects_ids(
	self.start.find_parents('ul'), ['bottom', 'middle', 'top'])
	self.assert_selects_ids(
	self.start.find_parents('ul', id="middle"), ['middle'])

	def test_find_parent(self):
	assert self.start.find_parent('ul')['id'] == 'bottom'
	assert self.start.find_parent('ul', id='top')['id'] == 'top'

	def test_parent_of_text_element(self):
	text = self.tree.find(string="Start here")
	assert text.parent.name == 'b'

	def test_text_element_find_parent(self):
	text = self.tree.find(string="Start here")
	assert text.find_parent('ul')['id'] == 'bottom'

	def test_parent_generator(self):
	parents = [parent['id'] for parent in self.start.parents
	if parent is not None and 'id' in parent.attrs]
	assert parents, ['bottom', 'middle' == 'top']


	class ProximityTest(SoupTest):

	def setup_method(self):
	self.tree = self.soup(
	'<html id="start"><head></head><body><b id="1">One</b><b id="2">Two</b><b id="3">Three</b></body></html>')


	class TestNextOperations(ProximityTest):

	def setup_method(self):
	super(TestNextOperations, self).setup_method()
	self.start = self.tree.b

	def test_next(self):
	assert self.start.next_element == "One"
	assert self.start.next_element.next_element['id'] == "2"

	def test_next_of_last_item_is_none(self):
	last = self.tree.find(string="Three")
	assert last.next_element == None

	def test_next_of_root_is_none(self):
	# The document root is outside the next/previous chain.
	assert self.tree.next_element == None

	def test_find_all_next(self):
	self.assert_selects(self.start.find_all_next('b'), ["Two", "Three"])
	self.start.find_all_next(id=3)
	self.assert_selects(self.start.find_all_next(id=3), ["Three"])

	def test_find_next(self):
	assert self.start.find_next('b')['id'] == '2'
	assert self.start.find_next(string="Three") == "Three"

	def test_find_next_for_text_element(self):
	text = self.tree.find(string="One")
	assert text.find_next("b").string == "Two"
	self.assert_selects(text.find_all_next("b"), ["Two", "Three"])

	def test_next_generator(self):
	start = self.tree.find(string="Two")
	successors = [node for node in start.next_elements]
	# There are two successors: the final <b> tag and its text contents.
	tag, contents = successors
	assert tag['id'] == '3'
	assert contents == "Three"

	class TestPreviousOperations(ProximityTest):

	def setup_method(self):
	super(TestPreviousOperations, self).setup_method()
	self.end = self.tree.find(string="Three")

	def test_previous(self):
	assert self.end.previous_element['id'] == "3"
	assert self.end.previous_element.previous_element == "Two"

	def test_previous_of_first_item_is_none(self):
	first = self.tree.find('html')
	assert first.previous_element == None

	def test_previous_of_root_is_none(self):
	# The document root is outside the next/previous chain.
	assert self.tree.previous_element == None

	def test_find_all_previous(self):
	# The <b> tag containing the "Three" node is the predecessor
	# of the "Three" node itself, which is why "Three" shows up
	# here.
	self.assert_selects(
	self.end.find_all_previous('b'), ["Three", "Two", "One"])
	self.assert_selects(self.end.find_all_previous(id=1), ["One"])

	def test_find_previous(self):
	assert self.end.find_previous('b')['id'] == '3'
	assert self.end.find_previous(string="One") == "One"

	def test_find_previous_for_text_element(self):
	text = self.tree.find(string="Three")
	assert text.find_previous("b").string == "Three"
	self.assert_selects(
	text.find_all_previous("b"), ["Three", "Two", "One"])

	def test_previous_generator(self):
	start = self.tree.find(string="One")
	predecessors = [node for node in start.previous_elements]

	# There are four predecessors: the <b> tag containing "One"
	# the <body> tag, the <head> tag, and the <html> tag.
	b, body, head, html = predecessors
	assert b['id'] == '1'
	assert body.name == "body"
	assert head.name == "head"
	assert html.name == "html"


	class SiblingTest(SoupTest):

	def setup_method(self):
	markup = '''<html>
	<span id="1">
	<span id="1.1"></span>
	</span>
	<span id="2">
	<span id="2.1"></span>
	</span>
	<span id="3">
	<span id="3.1"></span>
	</span>
	<span id="4"></span>
	</html>'''
	# All that whitespace looks good but makes the tests more
	# difficult. Get rid of it.
	markup = re.compile(r"\n\s*").sub("", markup)
	self.tree = self.soup(markup)


	class TestNextSibling(SiblingTest):

	def setup_method(self):
	super(TestNextSibling, self).setup_method()
	self.start = self.tree.find(id="1")

	def test_next_sibling_of_root_is_none(self):
	assert self.tree.next_sibling == None

	def test_next_sibling(self):
	assert self.start.next_sibling['id'] == '2'
	assert self.start.next_sibling.next_sibling['id'] == '3'

	# Note the difference between next_sibling and next_element.
	assert self.start.next_element['id'] == '1.1'

	def test_next_sibling_may_not_exist(self):
	assert self.tree.html.next_sibling == None

	nested_span = self.tree.find(id="1.1")
	assert nested_span.next_sibling == None

	last_span = self.tree.find(id="4")
	assert last_span.next_sibling == None

	def test_find_next_sibling(self):
	assert self.start.find_next_sibling('span')['id'] == '2'

	def test_next_siblings(self):
	self.assert_selects_ids(self.start.find_next_siblings("span"),
	['2', '3', '4'])

	self.assert_selects_ids(self.start.find_next_siblings(id='3'), ['3'])

	def test_next_sibling_for_text_element(self):
	soup = self.soup("Foo<b>bar</b>baz")
	start = soup.find(string="Foo")
	assert start.next_sibling.name == 'b'
	assert start.next_sibling.next_sibling == 'baz'

	self.assert_selects(start.find_next_siblings('b'), ['bar'])
	assert start.find_next_sibling(string="baz") == "baz"
	assert start.find_next_sibling(string="nonesuch") == None


	class TestPreviousSibling(SiblingTest):

	def setup_method(self):
	super(TestPreviousSibling, self).setup_method()
	self.end = self.tree.find(id="4")

	def test_previous_sibling_of_root_is_none(self):
	assert self.tree.previous_sibling == None

	def test_previous_sibling(self):
	assert self.end.previous_sibling['id'] == '3'
	assert self.end.previous_sibling.previous_sibling['id'] == '2'

	# Note the difference between previous_sibling and previous_element.
	assert self.end.previous_element['id'] == '3.1'

	def test_previous_sibling_may_not_exist(self):
	assert self.tree.html.previous_sibling == None

	nested_span = self.tree.find(id="1.1")
	assert nested_span.previous_sibling == None

	first_span = self.tree.find(id="1")
	assert first_span.previous_sibling == None

	def test_find_previous_sibling(self):
	assert self.end.find_previous_sibling('span')['id'] == '3'

	def test_previous_siblings(self):
	self.assert_selects_ids(self.end.find_previous_siblings("span"),
	['3', '2', '1'])

	self.assert_selects_ids(self.end.find_previous_siblings(id='1'), ['1'])

	def test_previous_sibling_for_text_element(self):
	soup = self.soup("Foo<b>bar</b>baz")
	start = soup.find(string="baz")
	assert start.previous_sibling.name == 'b'
	assert start.previous_sibling.previous_sibling == 'Foo'

	self.assert_selects(start.find_previous_siblings('b'), ['bar'])
	assert start.find_previous_sibling(string="Foo") == "Foo"
	assert start.find_previous_sibling(string="nonesuch") == None


	class TestTreeModification(SoupTest):

	def test_attribute_modification(self):
	soup = self.soup('<a id="1"></a>')
	soup.a['id'] = 2
	assert soup.decode() == self.document_for('<a id="2"></a>')
	del(soup.a['id'])
	assert soup.decode() == self.document_for('<a></a>')
	soup.a['id2'] = 'foo'
	assert soup.decode() == self.document_for('<a id2="foo"></a>')

	def test_new_tag_creation(self):
	builder = builder_registry.lookup('html')()
	soup = self.soup("<body></body>", builder=builder)
	a = Tag(soup, builder, 'a')
	ol = Tag(soup, builder, 'ol')
	a['href'] = 'http://foo.com/'
	soup.body.insert(0, a)
	soup.body.insert(1, ol)
	assert soup.body.encode() == b'<body><a href="http://foo.com/"></a><ol></ol></body>'

	def test_append_to_contents_moves_tag(self):
	doc = """<p id="1">Don't leave me <b>here</b>.</p>
	<p id="2">Don\'t leave!</p>"""
	soup = self.soup(doc)
	second_para = soup.find(id='2')
	bold = soup.b

	# Move the <b> tag to the end of the second paragraph.
	soup.find(id='2').append(soup.b)

	# The <b> tag is now a child of the second paragraph.
	assert bold.parent == second_para

	assert soup.decode() == self.document_for(
	'<p id="1">Don\'t leave me .</p>\n'
	'<p id="2">Don\'t leave!<b>here</b></p>'
	)

	def test_replace_with_returns_thing_that_was_replaced(self):
	text = "<a></a><b><c></c></b>"
	soup = self.soup(text)
	a = soup.a
	new_a = a.replace_with(soup.c)
	assert a == new_a

	def test_unwrap_returns_thing_that_was_replaced(self):
	text = "<a><b></b><c></c></a>"
	soup = self.soup(text)
	a = soup.a
	new_a = a.unwrap()
	assert a == new_a

	def test_replace_with_and_unwrap_give_useful_exception_when_tag_has_no_parent(self):
	soup = self.soup("<a><b>Foo</b></a><c>Bar</c>")
	a = soup.a
	a.extract()
	assert None == a.parent
	with pytest.raises(ValueError):
	a.unwrap()
	with pytest.raises(ValueError):
	a.replace_with(soup.c)

	def test_replace_tag_with_itself(self):
	text = "<a><b></b><c>Foo<d></d></c></a><a><e></e></a>"
	soup = self.soup(text)
	c = soup.c
	soup.c.replace_with(c)
	assert soup.decode() == self.document_for(text)

	def test_replace_tag_with_its_parent_raises_exception(self):
	text = "<a><b></b></a>"
	soup = self.soup(text)
	with pytest.raises(ValueError):
	soup.b.replace_with(soup.a)

	def test_insert_tag_into_itself_raises_exception(self):
	text = "<a><b></b></a>"
	soup = self.soup(text)
	with pytest.raises(ValueError):
	soup.a.insert(0, soup.a)

	def test_insert_beautifulsoup_object_inserts_children(self):
	"""Inserting one BeautifulSoup object into another actually inserts all
	of its children -- you'll never combine BeautifulSoup objects.
	"""
	soup = self.soup("<p>And now, a word:</p><p>And we're back.</p>")

	text = "<p>p2</p><p>p3</p>"
	to_insert = self.soup(text)
	soup.insert(1, to_insert)

	for i in soup.descendants:
	assert not isinstance(i, BeautifulSoup)

	p1, p2, p3, p4 = list(soup.children)
	assert "And now, a word:" == p1.string
	assert "p2" == p2.string
	assert "p3" == p3.string
	assert "And we're back." == p4.string


	def test_replace_with_maintains_next_element_throughout(self):
	soup = self.soup('<p><a>one</a><b>three</b></p>')
	a = soup.a
	b = a.contents[0]
	# Make it so the <a> tag has two text children.
	a.insert(1, "two")

	# Now replace each one with the empty string.
	left, right = a.contents
	left.replaceWith('')
	right.replaceWith('')

	# The <b> tag is still connected to the tree.
	assert "three" == soup.b.string

	def test_replace_final_node(self):
	soup = self.soup("<b>Argh!</b>")
	soup.find(string="Argh!").replace_with("Hooray!")
	new_text = soup.find(string="Hooray!")
	b = soup.b
	assert new_text.previous_element == b
	assert new_text.parent == b
	assert new_text.previous_element.next_element == new_text
	assert new_text.next_element == None

	def test_consecutive_text_nodes(self):
	# A builder should never create two consecutive text nodes,
	# but if you insert one next to another, Beautiful Soup will
	# handle it correctly.
	soup = self.soup("<a><b>Argh!</b><c></c></a>")
	soup.b.insert(1, "Hooray!")

	assert soup.decode() == self.document_for(
	"<a><b>Argh!Hooray!</b><c></c></a>"
	)

	new_text = soup.find(string="Hooray!")
	assert new_text.previous_element == "Argh!"
	assert new_text.previous_element.next_element == new_text

	assert new_text.previous_sibling == "Argh!"
	assert new_text.previous_sibling.next_sibling == new_text

	assert new_text.next_sibling == None
	assert new_text.next_element == soup.c

	def test_insert_string(self):
	soup = self.soup("<a></a>")
	soup.a.insert(0, "bar")
	soup.a.insert(0, "foo")
	# The string were added to the tag.
	assert ["foo", "bar"] == soup.a.contents
	# And they were converted to NavigableStrings.
	assert soup.a.contents[0].next_element == "bar"

	def test_insert_tag(self):
	builder = self.default_builder()
	soup = self.soup(
	"<a><b>Find</b><c>lady!</c><d></d></a>", builder=builder)
	magic_tag = Tag(soup, builder, 'magictag')
	magic_tag.insert(0, "the")
	soup.a.insert(1, magic_tag)

	assert soup.decode() == self.document_for(
	"<a><b>Find</b><magictag>the</magictag><c>lady!</c><d></d></a>"
	)

	# Make sure all the relationships are hooked up correctly.
	b_tag = soup.b
	assert b_tag.next_sibling == magic_tag
	assert magic_tag.previous_sibling == b_tag

	find = b_tag.find(string="Find")
	assert find.next_element == magic_tag
	assert magic_tag.previous_element == find

	c_tag = soup.c
	assert magic_tag.next_sibling == c_tag
	assert c_tag.previous_sibling == magic_tag

	the = magic_tag.find(string="the")
	assert the.parent == magic_tag
	assert the.next_element == c_tag
	assert c_tag.previous_element == the

	def test_append_child_thats_already_at_the_end(self):
	data = "<a><b></b></a>"
	soup = self.soup(data)
	soup.a.append(soup.b)
	assert data == soup.decode()

	def test_extend(self):
	data = "<a><b><c><d><e><f><g></g></f></e></d></c></b></a>"
	soup = self.soup(data)
	l = [soup.g, soup.f, soup.e, soup.d, soup.c, soup.b]
	soup.a.extend(l)
	assert "<a><g></g><f></f><e></e><d></d><c></c><b></b></a>" == soup.decode()

	@pytest.mark.parametrize(
	"get_tags", [lambda tag: tag, lambda tag: tag.contents]
	)
	def test_extend_with_another_tags_contents(self, get_tags):
	data = '<body><div id="d1"><a>1</a><a>2</a><a>3</a><a>4</a></div><div id="d2"></div></body>'
	soup = self.soup(data)
	d1 = soup.find('div', id='d1')
	d2 = soup.find('div', id='d2')
	tags = get_tags(d1)
	d2.extend(tags)
	assert '<div id="d1"></div>' == d1.decode()
	assert '<div id="d2"><a>1</a><a>2</a><a>3</a><a>4</a></div>' == d2.decode()

	def test_move_tag_to_beginning_of_parent(self):
	data = "<a><b></b><c></c><d></d></a>"
	soup = self.soup(data)
	soup.a.insert(0, soup.d)
	assert "<a><d></d><b></b><c></c></a>" == soup.decode()

	def test_insert_works_on_empty_element_tag(self):
	# This is a little strange, since most HTML parsers don't allow
	# markup like this to come through. But in general, we don't
	# know what the parser would or wouldn't have allowed, so
	# I'm letting this succeed for now.
	soup = self.soup("<br/>")
	soup.br.insert(1, "Contents")
	assert str(soup.br) == "<br>Contents</br>"

	def test_insert_before(self):
	soup = self.soup("<a>foo</a><b>bar</b>")
	soup.b.insert_before("BAZ")
	soup.a.insert_before("QUUX")
	assert soup.decode() == self.document_for(
	"QUUX<a>foo</a>BAZ<b>bar</b>"
	)

	soup.a.insert_before(soup.b)
	assert soup.decode() == self.document_for("QUUX<b>bar</b><a>foo</a>BAZ")

	# Can't insert an element before itself.
	b = soup.b
	with pytest.raises(ValueError):
	b.insert_before(b)

	# Can't insert before if an element has no parent.
	b.extract()
	with pytest.raises(ValueError):
	b.insert_before("nope")

	# Can insert an identical element
	soup = self.soup("<a>")
	soup.a.insert_before(soup.new_tag("a"))

	# TODO: OK but what happens?

	def test_insert_multiple_before(self):
	soup = self.soup("<a>foo</a><b>bar</b>")
	soup.b.insert_before("BAZ", " ", "QUUX")
	soup.a.insert_before("QUUX", " ", "BAZ")
	assert soup.decode() == self.document_for(
	"QUUX BAZ<a>foo</a>BAZ QUUX<b>bar</b>"
	)

	soup.a.insert_before(soup.b, "FOO")
	assert soup.decode() == self.document_for(
	"QUUX BAZ<b>bar</b>FOO<a>foo</a>BAZ QUUX"
	)

	def test_insert_after(self):
	soup = self.soup("<a>foo</a><b>bar</b>")
	soup.b.insert_after("BAZ")
	soup.a.insert_after("QUUX")
	assert soup.decode() == self.document_for(
	"<a>foo</a>QUUX<b>bar</b>BAZ"
	)
	soup.b.insert_after(soup.a)
	assert soup.decode() == self.document_for("QUUX<b>bar</b><a>foo</a>BAZ")

	# Can't insert an element after itself.
	b = soup.b
	with pytest.raises(ValueError):
	b.insert_after(b)

	# Can't insert after if an element has no parent.
	b.extract()
	with pytest.raises(ValueError):
	b.insert_after("nope")

	# Can insert an identical element
	soup = self.soup("<a>")
	soup.a.insert_before(soup.new_tag("a"))

	# TODO: OK but what does it look like?

	def test_insert_multiple_after(self):
	soup = self.soup("<a>foo</a><b>bar</b>")
	soup.b.insert_after("BAZ", " ", "QUUX")
	soup.a.insert_after("QUUX", " ", "BAZ")
	assert soup.decode() == self.document_for(
	"<a>foo</a>QUUX BAZ<b>bar</b>BAZ QUUX"
	)
	soup.b.insert_after(soup.a, "FOO ")
	assert soup.decode() == self.document_for(
	"QUUX BAZ<b>bar</b><a>foo</a>FOO BAZ QUUX"
	)

	def test_insert_after_raises_exception_if_after_has_no_meaning(self):
	soup = self.soup("")
	tag = soup.new_tag("a")
	string = soup.new_string("")
	with pytest.raises(ValueError):
	string.insert_after(tag)
	with pytest.raises(NotImplementedError):
	soup.insert_after(tag)
	with pytest.raises(ValueError):
	tag.insert_after(tag)

	def test_insert_before_raises_notimplementederror_if_before_has_no_meaning(self):
	soup = self.soup("")
	tag = soup.new_tag("a")
	string = soup.new_string("")
	with pytest.raises(ValueError):
	string.insert_before(tag)
	with pytest.raises(NotImplementedError):
	soup.insert_before(tag)
	with pytest.raises(ValueError):
	tag.insert_before(tag)

	def test_replace_with(self):
	soup = self.soup(
	"<p>There's <b>no</b> business like <b>show</b> business</p>")
	no, show = soup.find_all('b')
	show.replace_with(no)
	assert soup.decode() == self.document_for(
	"<p>There's business like <b>no</b> business</p>"
	)

	assert show.parent == None
	assert no.parent == soup.p
	assert no.next_element == "no"
	assert no.next_sibling == " business"

	def test_replace_with_errors(self):
	# Can't replace a tag that's not part of a tree.
	a_tag = Tag(name="a")
	with pytest.raises(ValueError):
	a_tag.replace_with("won't work")

	# Can't replace a tag with its parent.
	a_tag = self.soup("<a><b></b></a>").a
	with pytest.raises(ValueError):
	a_tag.b.replace_with(a_tag)

	# Or with a list that includes its parent.
	with pytest.raises(ValueError):
	a_tag.b.replace_with("string1", a_tag, "string2")

	def test_replace_with_multiple(self):
	data = "<a><b></b><c></c></a>"
	soup = self.soup(data)
	d_tag = soup.new_tag("d")
	d_tag.string = "Text In D Tag"
	e_tag = soup.new_tag("e")
	f_tag = soup.new_tag("f")
	a_string = "Random Text"
	soup.c.replace_with(d_tag, e_tag, a_string, f_tag)
	assert soup.decode() == "<a><b></b><d>Text In D Tag</d><e></e>Random Text<f></f></a>"
	assert soup.b.next_element == d_tag
	assert d_tag.string.next_element==e_tag
	assert e_tag.next_element.string == a_string
	assert e_tag.next_element.next_element == f_tag

	def test_replace_first_child(self):
	data = "<a><b></b><c></c></a>"
	soup = self.soup(data)
	soup.b.replace_with(soup.c)
	assert "<a><c></c></a>" == soup.decode()

	def test_replace_last_child(self):
	data = "<a><b></b><c></c></a>"
	soup = self.soup(data)
	soup.c.replace_with(soup.b)
	assert "<a><b></b></a>" == soup.decode()

	def test_nested_tag_replace_with(self):
	soup = self.soup(
	"""<a>We<b>reserve<c>the</c><d>right</d></b></a><e>to<f>refuse</f><g>service</g></e>""")

	# Replace the entire <b> tag and its contents ("reserve the
	# right") with the <f> tag ("refuse").
	remove_tag = soup.b
	move_tag = soup.f
	remove_tag.replace_with(move_tag)

	assert soup.decode() == self.document_for(
	"<a>We<f>refuse</f></a><e>to<g>service</g></e>"
	)

	# The <b> tag is now an orphan.
	assert remove_tag.parent == None
	assert remove_tag.find(string="right").next_element == None
	assert remove_tag.previous_element == None
	assert remove_tag.next_sibling == None
	assert remove_tag.previous_sibling == None

	# The <f> tag is now connected to the <a> tag.
	assert move_tag.parent == soup.a
	assert move_tag.previous_element == "We"
	assert move_tag.next_element.next_element == soup.e
	assert move_tag.next_sibling == None

	# The gap where the <f> tag used to be has been mended, and
	# the word "to" is now connected to the <g> tag.
	to_text = soup.find(string="to")
	g_tag = soup.g
	assert to_text.next_element == g_tag
	assert to_text.next_sibling == g_tag
	assert g_tag.previous_element == to_text
	assert g_tag.previous_sibling == to_text

	def test_unwrap(self):
	tree = self.soup("""
	<p>Unneeded <em>formatting</em> is unneeded</p>
	""")
	tree.em.unwrap()
	assert tree.em == None
	assert tree.p.text == "Unneeded formatting is unneeded"

	def test_wrap(self):
	soup = self.soup("I wish I was bold.")
	value = soup.string.wrap(soup.new_tag("b"))
	assert value.decode() == "<b>I wish I was bold.</b>"
	assert soup.decode() == self.document_for("<b>I wish I was bold.</b>")

	def test_wrap_extracts_tag_from_elsewhere(self):
	soup = self.soup("<b></b>I wish I was bold.")
	soup.b.next_sibling.wrap(soup.b)
	assert soup.decode() == self.document_for("<b>I wish I was bold.</b>")

	def test_wrap_puts_new_contents_at_the_end(self):
	soup = self.soup("<b>I like being bold.</b>I wish I was bold.")
	soup.b.next_sibling.wrap(soup.b)
	assert 2 == len(soup.b.contents)
	assert soup.decode() == self.document_for(
	"<b>I like being bold.I wish I was bold.</b>"
	)

	def test_extract(self):
	soup = self.soup(
	'<html><body>Some content. <div id="nav">Nav crap</div> More content.</body></html>')

	assert len(soup.body.contents) == 3
	extracted = soup.find(id="nav").extract()

	assert soup.decode() == "<html><body>Some content. More content.</body></html>"
	assert extracted.decode() == '<div id="nav">Nav crap</div>'

	# The extracted tag is now an orphan.
	assert len(soup.body.contents) == 2
	assert extracted.parent == None
	assert extracted.previous_element == None
	assert extracted.next_element.next_element == None

	# The gap where the extracted tag used to be has been mended.
	content_1 = soup.find(string="Some content. ")
	content_2 = soup.find(string=" More content.")
	assert content_1.next_element == content_2
	assert content_1.next_sibling == content_2
	assert content_2.previous_element == content_1
	assert content_2.previous_sibling == content_1

	def test_extract_distinguishes_between_identical_strings(self):
	soup = self.soup("<a>foo</a><b>bar</b>")
	foo_1 = soup.a.string
	bar_1 = soup.b.string
	foo_2 = soup.new_string("foo")
	bar_2 = soup.new_string("bar")
	soup.a.append(foo_2)
	soup.b.append(bar_2)

	# Now there are two identical strings in the <a> tag, and two
	# in the <b> tag. Let's remove the first "foo" and the second
	# "bar".
	foo_1.extract()
	bar_2.extract()
	assert foo_2 == soup.a.string
	assert bar_2 == soup.b.string

	def test_extract_multiples_of_same_tag(self):
	soup = self.soup("""
	<html>
	<head>
	<script>foo</script>
	</head>
	<body>
	<script>bar</script>
	<a></a>
	</body>
	<script>baz</script>
	</html>""")
	[soup.script.extract() for i in soup.find_all("script")]
	assert "<body>\n\n<a></a>\n</body>" == str(soup.body)


	def test_extract_works_when_element_is_surrounded_by_identical_strings(self):
	soup = self.soup(
	'<html>\n'
	'<body>hi</body>\n'
	'</html>')
	soup.find('body').extract()
	assert None == soup.find('body')


	def test_clear(self):
	"""Tag.clear()"""
	soup = self.soup("<p><a>String <em>Italicized</em></a> and another</p>")
	# clear using extract()
	a = soup.a
	soup.p.clear()
	assert len(soup.p.contents) == 0
	assert hasattr(a, "contents")

	# clear using decompose()
	em = a.em
	a.clear(decompose=True)
	assert 0 == len(em.contents)


	def test_decompose(self):
	# Test PageElement.decompose() and PageElement.decomposed
	soup = self.soup("<p><a>String <em>Italicized</em></a></p><p>Another para</p>")
	p1, p2 = soup.find_all('p')
	a = p1.a
	text = p1.em.string
	for i in [p1, p2, a, text]:
	assert False == i.decomposed

	# This sets p1 and everything beneath it to decomposed.
	p1.decompose()
	for i in [p1, a, text]:
	assert True == i.decomposed
	# p2 is unaffected.
	assert False == p2.decomposed

	def test_string_set(self):
	"""Tag.string = 'string'"""
	soup = self.soup("<a></a> <b><c></c></b>")
	soup.a.string = "foo"
	assert soup.a.contents == ["foo"]
	soup.b.string = "bar"
	assert soup.b.contents == ["bar"]

	def test_string_set_does_not_affect_original_string(self):
	soup = self.soup("<a><b>foo</b><c>bar</c>")
	soup.b.string = soup.c.string
	assert soup.a.encode() == b"<a><b>bar</b><c>bar</c></a>"

	def test_set_string_preserves_class_of_string(self):
	soup = self.soup("<a></a>")
	cdata = CData("foo")
	soup.a.string = cdata
	assert isinstance(soup.a.string, CData)


	class TestDeprecatedArguments(SoupTest):

	@pytest.mark.parametrize(
	"method_name", [
	"find", "find_all", "find_parent", "find_parents",
	"find_next", "find_all_next", "find_previous",
	"find_all_previous", "find_next_sibling", "find_next_siblings",
	"find_previous_sibling", "find_previous_siblings",
	]
	)
	def test_find_type_method_string(self, method_name):
	soup = self.soup("<a>some</a><b>markup</b>")
	method = getattr(soup.b, method_name)
	with warnings.catch_warnings(record=True) as w:
	method(text='markup')
	[warning] = w
	assert warning.filename == __file__
	msg = str(warning.message)
	assert msg == "The 'text' argument to find()-type methods is deprecated. Use 'string' instead."

	def test_soupstrainer_constructor_string(self):
	with warnings.catch_warnings(record=True) as w:
	strainer = SoupStrainer(text="text")
	assert strainer.text == 'text'
	[warning] = w
	msg = str(warning.message)
	assert warning.filename == __file__
	assert msg == "The 'text' argument to the SoupStrainer constructor is deprecated. Use 'string' instead."