cpython/Lib/test/test_pulldom.py

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import io
import unittest
import xml.sax
from xml.sax.xmlreader import AttributesImpl
from xml.sax.handler import feature_external_ges
from xml.dom import pulldom
from test.support import findfile
tstfile = findfile("test.xml", subdir="xmltestdata")
# A handy XML snippet, containing attributes, a namespace prefix, and a
# self-closing tag:
SMALL_SAMPLE = """<?xml version="1.0"?>
<html xmlns="http://www.w3.org/1999/xhtml" xmlns:xdc="http://www.xml.com/books">
<!-- A comment -->
<title>Introduction to XSL</title>
<hr/>
<p><xdc:author xdc:attrib="prefixed attribute" attrib="other attrib">A. Namespace</xdc:author></p>
</html>"""
class PullDOMTestCase(unittest.TestCase):
def test_parse(self):
"""Minimal test of DOMEventStream.parse()"""
# This just tests that parsing from a stream works. Actual parser
# semantics are tested using parseString with a more focused XML
# fragment.
# Test with a filename:
handler = pulldom.parse(tstfile)
self.addCleanup(handler.stream.close)
list(handler)
# Test with a file object:
with open(tstfile, "rb") as fin:
list(pulldom.parse(fin))
def test_parse_semantics(self):
"""Test DOMEventStream parsing semantics."""
items = pulldom.parseString(SMALL_SAMPLE)
evt, node = next(items)
# Just check the node is a Document:
self.assertTrue(hasattr(node, "createElement"))
self.assertEqual(pulldom.START_DOCUMENT, evt)
evt, node = next(items)
self.assertEqual(pulldom.START_ELEMENT, evt)
self.assertEqual("html", node.tagName)
self.assertEqual(2, len(node.attributes))
self.assertEqual(node.attributes.getNamedItem("xmlns:xdc").value,
"http://www.xml.com/books")
evt, node = next(items)
self.assertEqual(pulldom.CHARACTERS, evt) # Line break
evt, node = next(items)
# XXX - A comment should be reported here!
# self.assertEqual(pulldom.COMMENT, evt)
# Line break after swallowed comment:
self.assertEqual(pulldom.CHARACTERS, evt)
evt, node = next(items)
self.assertEqual("title", node.tagName)
title_node = node
evt, node = next(items)
self.assertEqual(pulldom.CHARACTERS, evt)
self.assertEqual("Introduction to XSL", node.data)
evt, node = next(items)
self.assertEqual(pulldom.END_ELEMENT, evt)
self.assertEqual("title", node.tagName)
self.assertTrue(title_node is node)
evt, node = next(items)
self.assertEqual(pulldom.CHARACTERS, evt)
evt, node = next(items)
self.assertEqual(pulldom.START_ELEMENT, evt)
self.assertEqual("hr", node.tagName)
evt, node = next(items)
self.assertEqual(pulldom.END_ELEMENT, evt)
self.assertEqual("hr", node.tagName)
evt, node = next(items)
self.assertEqual(pulldom.CHARACTERS, evt)
evt, node = next(items)
self.assertEqual(pulldom.START_ELEMENT, evt)
self.assertEqual("p", node.tagName)
evt, node = next(items)
self.assertEqual(pulldom.START_ELEMENT, evt)
self.assertEqual("xdc:author", node.tagName)
evt, node = next(items)
self.assertEqual(pulldom.CHARACTERS, evt)
evt, node = next(items)
self.assertEqual(pulldom.END_ELEMENT, evt)
self.assertEqual("xdc:author", node.tagName)
evt, node = next(items)
self.assertEqual(pulldom.END_ELEMENT, evt)
evt, node = next(items)
self.assertEqual(pulldom.CHARACTERS, evt)
evt, node = next(items)
self.assertEqual(pulldom.END_ELEMENT, evt)
# XXX No END_DOCUMENT item is ever obtained:
#evt, node = next(items)
#self.assertEqual(pulldom.END_DOCUMENT, evt)
def test_expandItem(self):
"""Ensure expandItem works as expected."""
items = pulldom.parseString(SMALL_SAMPLE)
# Loop through the nodes until we get to a "title" start tag:
for evt, item in items:
if evt == pulldom.START_ELEMENT and item.tagName == "title":
items.expandNode(item)
self.assertEqual(1, len(item.childNodes))
break
else:
self.fail("No \"title\" element detected in SMALL_SAMPLE!")
# Loop until we get to the next start-element:
for evt, node in items:
if evt == pulldom.START_ELEMENT:
break
self.assertEqual("hr", node.tagName,
"expandNode did not leave DOMEventStream in the correct state.")
# Attempt to expand a standalone element:
items.expandNode(node)
self.assertEqual(next(items)[0], pulldom.CHARACTERS)
evt, node = next(items)
self.assertEqual(node.tagName, "p")
items.expandNode(node)
next(items) # Skip character data
evt, node = next(items)
self.assertEqual(node.tagName, "html")
with self.assertRaises(StopIteration):
next(items)
items.clear()
self.assertIsNone(items.parser)
self.assertIsNone(items.stream)
@unittest.expectedFailure
def test_comment(self):
"""PullDOM does not receive "comment" events."""
items = pulldom.parseString(SMALL_SAMPLE)
for evt, _ in items:
if evt == pulldom.COMMENT:
break
else:
self.fail("No comment was encountered")
@unittest.expectedFailure
def test_end_document(self):
"""PullDOM does not receive "end-document" events."""
items = pulldom.parseString(SMALL_SAMPLE)
# Read all of the nodes up to and including </html>:
for evt, node in items:
if evt == pulldom.END_ELEMENT and node.tagName == "html":
break
try:
# Assert that the next node is END_DOCUMENT:
evt, node = next(items)
self.assertEqual(pulldom.END_DOCUMENT, evt)
except StopIteration:
self.fail(
"Ran out of events, but should have received END_DOCUMENT")
def test_getitem_deprecation(self):
parser = pulldom.parseString(SMALL_SAMPLE)
with self.assertWarnsRegex(DeprecationWarning,
r'Use iterator protocol instead'):
# This should have returned 'END_ELEMENT'.
self.assertEqual(parser[-1][0], pulldom.START_DOCUMENT)
def test_external_ges_default(self):
parser = pulldom.parseString(SMALL_SAMPLE)
saxparser = parser.parser
ges = saxparser.getFeature(feature_external_ges)
self.assertEqual(ges, False)
class ThoroughTestCase(unittest.TestCase):
"""Test the hard-to-reach parts of pulldom."""
def test_thorough_parse(self):
"""Test some of the hard-to-reach parts of PullDOM."""
self._test_thorough(pulldom.parse(None, parser=SAXExerciser()))
@unittest.expectedFailure
def test_sax2dom_fail(self):
"""SAX2DOM can"t handle a PI before the root element."""
pd = SAX2DOMTestHelper(None, SAXExerciser(), 12)
self._test_thorough(pd)
def test_thorough_sax2dom(self):
"""Test some of the hard-to-reach parts of SAX2DOM."""
pd = SAX2DOMTestHelper(None, SAX2DOMExerciser(), 12)
self._test_thorough(pd, False)
def _test_thorough(self, pd, before_root=True):
"""Test some of the hard-to-reach parts of the parser, using a mock
parser."""
evt, node = next(pd)
self.assertEqual(pulldom.START_DOCUMENT, evt)
# Just check the node is a Document:
self.assertTrue(hasattr(node, "createElement"))
if before_root:
evt, node = next(pd)
self.assertEqual(pulldom.COMMENT, evt)
self.assertEqual("a comment", node.data)
evt, node = next(pd)
self.assertEqual(pulldom.PROCESSING_INSTRUCTION, evt)
self.assertEqual("target", node.target)
self.assertEqual("data", node.data)
evt, node = next(pd)
self.assertEqual(pulldom.START_ELEMENT, evt)
self.assertEqual("html", node.tagName)
evt, node = next(pd)
self.assertEqual(pulldom.COMMENT, evt)
self.assertEqual("a comment", node.data)
evt, node = next(pd)
self.assertEqual(pulldom.PROCESSING_INSTRUCTION, evt)
self.assertEqual("target", node.target)
self.assertEqual("data", node.data)
evt, node = next(pd)
self.assertEqual(pulldom.START_ELEMENT, evt)
self.assertEqual("p", node.tagName)
evt, node = next(pd)
self.assertEqual(pulldom.CHARACTERS, evt)
self.assertEqual("text", node.data)
evt, node = next(pd)
self.assertEqual(pulldom.END_ELEMENT, evt)
self.assertEqual("p", node.tagName)
evt, node = next(pd)
self.assertEqual(pulldom.END_ELEMENT, evt)
self.assertEqual("html", node.tagName)
evt, node = next(pd)
self.assertEqual(pulldom.END_DOCUMENT, evt)
class SAXExerciser(object):
"""A fake sax parser that calls some of the harder-to-reach sax methods to
ensure it emits the correct events"""
def setContentHandler(self, handler):
self._handler = handler
def parse(self, _):
h = self._handler
h.startDocument()
# The next two items ensure that items preceding the first
# start_element are properly stored and emitted:
h.comment("a comment")
h.processingInstruction("target", "data")
h.startElement("html", AttributesImpl({}))
h.comment("a comment")
h.processingInstruction("target", "data")
h.startElement("p", AttributesImpl({"class": "paraclass"}))
h.characters("text")
h.endElement("p")
h.endElement("html")
h.endDocument()
def stub(self, *args, **kwargs):
"""Stub method. Does nothing."""
pass
setProperty = stub
setFeature = stub
class SAX2DOMExerciser(SAXExerciser):
"""The same as SAXExerciser, but without the processing instruction and
comment before the root element, because S2D can"t handle it"""
def parse(self, _):
h = self._handler
h.startDocument()
h.startElement("html", AttributesImpl({}))
h.comment("a comment")
h.processingInstruction("target", "data")
h.startElement("p", AttributesImpl({"class": "paraclass"}))
h.characters("text")
h.endElement("p")
h.endElement("html")
h.endDocument()
class SAX2DOMTestHelper(pulldom.DOMEventStream):
"""Allows us to drive SAX2DOM from a DOMEventStream."""
def reset(self):
self.pulldom = pulldom.SAX2DOM()
# This content handler relies on namespace support
self.parser.setFeature(xml.sax.handler.feature_namespaces, 1)
self.parser.setContentHandler(self.pulldom)
class SAX2DOMTestCase(unittest.TestCase):
def confirm(self, test, testname="Test"):
self.assertTrue(test, testname)
def test_basic(self):
"""Ensure SAX2DOM can parse from a stream."""
with io.StringIO(SMALL_SAMPLE) as fin:
sd = SAX2DOMTestHelper(fin, xml.sax.make_parser(),
len(SMALL_SAMPLE))
for evt, node in sd:
if evt == pulldom.START_ELEMENT and node.tagName == "html":
break
# Because the buffer is the same length as the XML, all the
# nodes should have been parsed and added:
self.assertGreater(len(node.childNodes), 0)
def testSAX2DOM(self):
"""Ensure SAX2DOM expands nodes as expected."""
sax2dom = pulldom.SAX2DOM()
sax2dom.startDocument()
sax2dom.startElement("doc", {})
sax2dom.characters("text")
sax2dom.startElement("subelm", {})
sax2dom.characters("text")
sax2dom.endElement("subelm")
sax2dom.characters("text")
sax2dom.endElement("doc")
sax2dom.endDocument()
doc = sax2dom.document
root = doc.documentElement
(text1, elm1, text2) = root.childNodes
text3 = elm1.childNodes[0]
self.assertIsNone(text1.previousSibling)
self.assertIs(text1.nextSibling, elm1)
self.assertIs(elm1.previousSibling, text1)
self.assertIs(elm1.nextSibling, text2)
self.assertIs(text2.previousSibling, elm1)
self.assertIsNone(text2.nextSibling)
self.assertIsNone(text3.previousSibling)
self.assertIsNone(text3.nextSibling)
self.assertIs(root.parentNode, doc)
self.assertIs(text1.parentNode, root)
self.assertIs(elm1.parentNode, root)
self.assertIs(text2.parentNode, root)
self.assertIs(text3.parentNode, elm1)
doc.unlink()
if __name__ == "__main__":
unittest.main()