Add stubs package for lxml. (#15697)

The stubs have some issues so this has some generous cast
and ignores in it, but it is better than not having stubs.

Note that confusing that Element is a function which creates
_Element instances (and similarly for Comment).
pull/14678/merge
Patrick Cloke 2023-05-31 13:06:57 -04:00 committed by GitHub
parent 874378c052
commit 6f18812bb0
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
10 changed files with 117 additions and 48 deletions

1
changelog.d/15697.misc Normal file
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@ -0,0 +1 @@
Improve type hints.

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@ -60,9 +60,6 @@ ignore_missing_imports = True
[mypy-ijson.*]
ignore_missing_imports = True
[mypy-lxml]
ignore_missing_imports = True
# https://github.com/msgpack/msgpack-python/issues/448
[mypy-msgpack]
ignore_missing_imports = True

25
poetry.lock generated
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@ -1,4 +1,4 @@
# This file is automatically @generated by Poetry and should not be changed by hand.
# This file is automatically @generated by Poetry 1.4.2 and should not be changed by hand.
[[package]]
name = "alabaster"
@ -1215,6 +1215,21 @@ html5 = ["html5lib"]
htmlsoup = ["BeautifulSoup4"]
source = ["Cython (>=0.29.7)"]
[[package]]
name = "lxml-stubs"
version = "0.4.0"
description = "Type annotations for the lxml package"
category = "dev"
optional = false
python-versions = "*"
files = [
{file = "lxml-stubs-0.4.0.tar.gz", hash = "sha256:184877b42127256abc2b932ba8bd0ab5ea80bd0b0fee618d16daa40e0b71abee"},
{file = "lxml_stubs-0.4.0-py3-none-any.whl", hash = "sha256:3b381e9e82397c64ea3cc4d6f79d1255d015f7b114806d4826218805c10ec003"},
]
[package.extras]
test = ["coverage[toml] (==5.2)", "pytest (>=6.0.0)", "pytest-mypy-plugins (==1.9.3)"]
[[package]]
name = "markdown-it-py"
version = "2.2.0"
@ -3409,22 +3424,22 @@ docs = ["Sphinx", "repoze.sphinx.autointerface"]
test = ["zope.i18nmessageid", "zope.testing", "zope.testrunner"]
[extras]
all = ["matrix-synapse-ldap3", "psycopg2", "psycopg2cffi", "psycopg2cffi-compat", "pysaml2", "authlib", "lxml", "sentry-sdk", "jaeger-client", "opentracing", "txredisapi", "hiredis", "Pympler", "pyicu"]
all = ["Pympler", "authlib", "hiredis", "jaeger-client", "lxml", "matrix-synapse-ldap3", "opentracing", "psycopg2", "psycopg2cffi", "psycopg2cffi-compat", "pyicu", "pysaml2", "sentry-sdk", "txredisapi"]
cache-memory = ["Pympler"]
jwt = ["authlib"]
matrix-synapse-ldap3 = ["matrix-synapse-ldap3"]
oidc = ["authlib"]
opentracing = ["jaeger-client", "opentracing"]
postgres = ["psycopg2", "psycopg2cffi", "psycopg2cffi-compat"]
redis = ["txredisapi", "hiredis"]
redis = ["hiredis", "txredisapi"]
saml2 = ["pysaml2"]
sentry = ["sentry-sdk"]
systemd = ["systemd-python"]
test = ["parameterized", "idna"]
test = ["idna", "parameterized"]
url-preview = ["lxml"]
user-search = ["pyicu"]
[metadata]
lock-version = "2.0"
python-versions = "^3.7.1"
content-hash = "ef3a16dd66177f7141239e1a2d3e07cc14c08f1e4e0c5127184d022bc062da52"
content-hash = "7ad11e62a675e09444cf33ca2de3216fc4efc5874a2575e54d95d577a52439d3"

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@ -314,6 +314,7 @@ black = ">=22.3.0"
ruff = "0.0.265"
# Typechecking
lxml-stubs = ">=0.4.0"
mypy = "*"
mypy-zope = "*"
types-bleach = ">=4.1.0"

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@ -14,7 +14,7 @@
import html
import logging
import urllib.parse
from typing import TYPE_CHECKING, List, Optional
from typing import TYPE_CHECKING, List, Optional, cast
import attr
@ -98,7 +98,7 @@ class OEmbedProvider:
# No match.
return None
def autodiscover_from_html(self, tree: "etree.Element") -> Optional[str]:
def autodiscover_from_html(self, tree: "etree._Element") -> Optional[str]:
"""
Search an HTML document for oEmbed autodiscovery information.
@ -109,18 +109,22 @@ class OEmbedProvider:
The URL to use for oEmbed information, or None if no URL was found.
"""
# Search for link elements with the proper rel and type attributes.
for tag in tree.xpath(
"//link[@rel='alternate'][@type='application/json+oembed']"
# Cast: the type returned by xpath depends on the xpath expression: mypy can't deduce this.
for tag in cast(
List["etree._Element"],
tree.xpath("//link[@rel='alternate'][@type='application/json+oembed']"),
):
if "href" in tag.attrib:
return tag.attrib["href"]
return cast(str, tag.attrib["href"])
# Some providers (e.g. Flickr) use alternative instead of alternate.
for tag in tree.xpath(
"//link[@rel='alternative'][@type='application/json+oembed']"
# Cast: the type returned by xpath depends on the xpath expression: mypy can't deduce this.
for tag in cast(
List["etree._Element"],
tree.xpath("//link[@rel='alternative'][@type='application/json+oembed']"),
):
if "href" in tag.attrib:
return tag.attrib["href"]
return cast(str, tag.attrib["href"])
return None
@ -212,11 +216,12 @@ class OEmbedProvider:
return OEmbedResult(open_graph_response, author_name, cache_age)
def _fetch_urls(tree: "etree.Element", tag_name: str) -> List[str]:
def _fetch_urls(tree: "etree._Element", tag_name: str) -> List[str]:
results = []
for tag in tree.xpath("//*/" + tag_name):
# Cast: the type returned by xpath depends on the xpath expression: mypy can't deduce this.
for tag in cast(List["etree._Element"], tree.xpath("//*/" + tag_name)):
if "src" in tag.attrib:
results.append(tag.attrib["src"])
results.append(cast(str, tag.attrib["src"]))
return results
@ -244,11 +249,12 @@ def calc_description_and_urls(open_graph_response: JsonDict, html_body: str) ->
parser = etree.HTMLParser(recover=True, encoding="utf-8")
# Attempt to parse the body. If this fails, log and return no metadata.
tree = etree.fromstring(html_body, parser)
# TODO Develop of lxml-stubs has this correct.
tree = etree.fromstring(html_body, parser) # type: ignore[arg-type]
# The data was successfully parsed, but no tree was found.
if tree is None:
return
return # type: ignore[unreachable]
# Attempt to find interesting URLs (images, videos, embeds).
if "og:image" not in open_graph_response:

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@ -24,6 +24,7 @@ from typing import (
Optional,
Set,
Union,
cast,
)
if TYPE_CHECKING:
@ -115,7 +116,7 @@ def _get_html_media_encodings(
def decode_body(
body: bytes, uri: str, content_type: Optional[str] = None
) -> Optional["etree.Element"]:
) -> Optional["etree._Element"]:
"""
This uses lxml to parse the HTML document.
@ -152,11 +153,12 @@ def decode_body(
# Attempt to parse the body. Returns None if the body was successfully
# parsed, but no tree was found.
return etree.fromstring(body, parser)
# TODO Develop of lxml-stubs has this correct.
return etree.fromstring(body, parser) # type: ignore[arg-type]
def _get_meta_tags(
tree: "etree.Element",
tree: "etree._Element",
property: str,
prefix: str,
property_mapper: Optional[Callable[[str], Optional[str]]] = None,
@ -175,9 +177,15 @@ def _get_meta_tags(
Returns:
A map of tag name to value.
"""
# This actually returns Dict[str, str], but the caller sets this as a variable
# which is Dict[str, Optional[str]].
results: Dict[str, Optional[str]] = {}
for tag in tree.xpath(
f"//*/meta[starts-with(@{property}, '{prefix}:')][@content][not(@content='')]"
# Cast: the type returned by xpath depends on the xpath expression: mypy can't deduce this.
for tag in cast(
List["etree._Element"],
tree.xpath(
f"//*/meta[starts-with(@{property}, '{prefix}:')][@content][not(@content='')]"
),
):
# if we've got more than 50 tags, someone is taking the piss
if len(results) >= 50:
@ -187,14 +195,15 @@ def _get_meta_tags(
)
return {}
key = tag.attrib[property]
key = cast(str, tag.attrib[property])
if property_mapper:
key = property_mapper(key)
new_key = property_mapper(key)
# None is a special value used to ignore a value.
if key is None:
if new_key is None:
continue
key = new_key
results[key] = tag.attrib["content"]
results[key] = cast(str, tag.attrib["content"])
return results
@ -219,7 +228,7 @@ def _map_twitter_to_open_graph(key: str) -> Optional[str]:
return "og" + key[7:]
def parse_html_to_open_graph(tree: "etree.Element") -> Dict[str, Optional[str]]:
def parse_html_to_open_graph(tree: "etree._Element") -> Dict[str, Optional[str]]:
"""
Parse the HTML document into an Open Graph response.
@ -276,24 +285,36 @@ def parse_html_to_open_graph(tree: "etree.Element") -> Dict[str, Optional[str]]:
if "og:title" not in og:
# Attempt to find a title from the title tag, or the biggest header on the page.
title = tree.xpath("((//title)[1] | (//h1)[1] | (//h2)[1] | (//h3)[1])/text()")
# Cast: the type returned by xpath depends on the xpath expression: mypy can't deduce this.
title = cast(
List["etree._ElementUnicodeResult"],
tree.xpath("((//title)[1] | (//h1)[1] | (//h2)[1] | (//h3)[1])/text()"),
)
if title:
og["og:title"] = title[0].strip()
else:
og["og:title"] = None
if "og:image" not in og:
meta_image = tree.xpath(
"//*/meta[translate(@itemprop, 'IMAGE', 'image')='image'][not(@content='')]/@content[1]"
# Cast: the type returned by xpath depends on the xpath expression: mypy can't deduce this.
meta_image = cast(
List["etree._ElementUnicodeResult"],
tree.xpath(
"//*/meta[translate(@itemprop, 'IMAGE', 'image')='image'][not(@content='')]/@content[1]"
),
)
# If a meta image is found, use it.
if meta_image:
og["og:image"] = meta_image[0]
else:
# Try to find images which are larger than 10px by 10px.
# Cast: the type returned by xpath depends on the xpath expression: mypy can't deduce this.
#
# TODO: consider inlined CSS styles as well as width & height attribs
images = tree.xpath("//img[@src][number(@width)>10][number(@height)>10]")
images = cast(
List["etree._Element"],
tree.xpath("//img[@src][number(@width)>10][number(@height)>10]"),
)
images = sorted(
images,
key=lambda i: (
@ -302,20 +323,29 @@ def parse_html_to_open_graph(tree: "etree.Element") -> Dict[str, Optional[str]]:
)
# If no images were found, try to find *any* images.
if not images:
images = tree.xpath("//img[@src][1]")
# Cast: the type returned by xpath depends on the xpath expression: mypy can't deduce this.
images = cast(List["etree._Element"], tree.xpath("//img[@src][1]"))
if images:
og["og:image"] = images[0].attrib["src"]
og["og:image"] = cast(str, images[0].attrib["src"])
# Finally, fallback to the favicon if nothing else.
else:
favicons = tree.xpath("//link[@href][contains(@rel, 'icon')]/@href[1]")
# Cast: the type returned by xpath depends on the xpath expression: mypy can't deduce this.
favicons = cast(
List["etree._ElementUnicodeResult"],
tree.xpath("//link[@href][contains(@rel, 'icon')]/@href[1]"),
)
if favicons:
og["og:image"] = favicons[0]
if "og:description" not in og:
# Check the first meta description tag for content.
meta_description = tree.xpath(
"//*/meta[translate(@name, 'DESCRIPTION', 'description')='description'][not(@content='')]/@content[1]"
# Cast: the type returned by xpath depends on the xpath expression: mypy can't deduce this.
meta_description = cast(
List["etree._ElementUnicodeResult"],
tree.xpath(
"//*/meta[translate(@name, 'DESCRIPTION', 'description')='description'][not(@content='')]/@content[1]"
),
)
# If a meta description is found with content, use it.
if meta_description:
@ -332,7 +362,7 @@ def parse_html_to_open_graph(tree: "etree.Element") -> Dict[str, Optional[str]]:
return og
def parse_html_description(tree: "etree.Element") -> Optional[str]:
def parse_html_description(tree: "etree._Element") -> Optional[str]:
"""
Calculate a text description based on an HTML document.
@ -368,6 +398,9 @@ def parse_html_description(tree: "etree.Element") -> Optional[str]:
"canvas",
"img",
"picture",
# etree.Comment is a function which creates an etree._Comment element.
# The "tag" attribute of an etree._Comment instance is confusingly the
# etree.Comment function instead of a string.
etree.Comment,
}
@ -381,8 +414,8 @@ def parse_html_description(tree: "etree.Element") -> Optional[str]:
def _iterate_over_text(
tree: Optional["etree.Element"],
tags_to_ignore: Set[Union[str, "etree.Comment"]],
tree: Optional["etree._Element"],
tags_to_ignore: Set[object],
stack_limit: int = 1024,
) -> Generator[str, None, None]:
"""Iterate over the tree returning text nodes in a depth first fashion,
@ -402,7 +435,7 @@ def _iterate_over_text(
# This is a stack whose items are elements to iterate over *or* strings
# to be returned.
elements: List[Union[str, "etree.Element"]] = [tree]
elements: List[Union[str, "etree._Element"]] = [tree]
while elements:
el = elements.pop()

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@ -24,7 +24,7 @@ from tests import unittest
try:
import lxml
except ImportError:
lxml = None
lxml = None # type: ignore[assignment]
class SummarizeTestCase(unittest.TestCase):
@ -160,6 +160,7 @@ class OpenGraphFromHtmlTestCase(unittest.TestCase):
"""
tree = decode_body(html, "http://example.com/test.html")
assert tree is not None
og = parse_html_to_open_graph(tree)
self.assertEqual(og, {"og:title": "Foo", "og:description": "Some text."})
@ -176,6 +177,7 @@ class OpenGraphFromHtmlTestCase(unittest.TestCase):
"""
tree = decode_body(html, "http://example.com/test.html")
assert tree is not None
og = parse_html_to_open_graph(tree)
self.assertEqual(og, {"og:title": "Foo", "og:description": "Some text."})
@ -195,6 +197,7 @@ class OpenGraphFromHtmlTestCase(unittest.TestCase):
"""
tree = decode_body(html, "http://example.com/test.html")
assert tree is not None
og = parse_html_to_open_graph(tree)
self.assertEqual(
@ -217,6 +220,7 @@ class OpenGraphFromHtmlTestCase(unittest.TestCase):
"""
tree = decode_body(html, "http://example.com/test.html")
assert tree is not None
og = parse_html_to_open_graph(tree)
self.assertEqual(og, {"og:title": "Foo", "og:description": "Some text."})
@ -231,6 +235,7 @@ class OpenGraphFromHtmlTestCase(unittest.TestCase):
"""
tree = decode_body(html, "http://example.com/test.html")
assert tree is not None
og = parse_html_to_open_graph(tree)
self.assertEqual(og, {"og:title": None, "og:description": "Some text."})
@ -246,6 +251,7 @@ class OpenGraphFromHtmlTestCase(unittest.TestCase):
"""
tree = decode_body(html, "http://example.com/test.html")
assert tree is not None
og = parse_html_to_open_graph(tree)
self.assertEqual(og, {"og:title": "Title", "og:description": "Title"})
@ -261,6 +267,7 @@ class OpenGraphFromHtmlTestCase(unittest.TestCase):
"""
tree = decode_body(html, "http://example.com/test.html")
assert tree is not None
og = parse_html_to_open_graph(tree)
self.assertEqual(og, {"og:title": "Title", "og:description": "Some text."})
@ -281,6 +288,7 @@ class OpenGraphFromHtmlTestCase(unittest.TestCase):
"""
tree = decode_body(html, "http://example.com/test.html")
assert tree is not None
og = parse_html_to_open_graph(tree)
self.assertEqual(og, {"og:title": "Title", "og:description": "Finally!"})
@ -296,6 +304,7 @@ class OpenGraphFromHtmlTestCase(unittest.TestCase):
"""
tree = decode_body(html, "http://example.com/test.html")
assert tree is not None
og = parse_html_to_open_graph(tree)
self.assertEqual(og, {"og:title": None, "og:description": "Some text."})
@ -324,6 +333,7 @@ class OpenGraphFromHtmlTestCase(unittest.TestCase):
<head><title>Foo</title></head><body>Some text.</body></html>
""".strip()
tree = decode_body(html, "http://example.com/test.html")
assert tree is not None
og = parse_html_to_open_graph(tree)
self.assertEqual(og, {"og:title": "Foo", "og:description": "Some text."})
@ -338,6 +348,7 @@ class OpenGraphFromHtmlTestCase(unittest.TestCase):
</html>
"""
tree = decode_body(html, "http://example.com/test.html", "invalid-encoding")
assert tree is not None
og = parse_html_to_open_graph(tree)
self.assertEqual(og, {"og:title": "Foo", "og:description": "Some text."})
@ -353,6 +364,7 @@ class OpenGraphFromHtmlTestCase(unittest.TestCase):
</html>
"""
tree = decode_body(html, "http://example.com/test.html")
assert tree is not None
og = parse_html_to_open_graph(tree)
self.assertEqual(og, {"og:title": "ÿÿ Foo", "og:description": "Some text."})
@ -367,6 +379,7 @@ class OpenGraphFromHtmlTestCase(unittest.TestCase):
</html>
"""
tree = decode_body(html, "http://example.com/test.html")
assert tree is not None
og = parse_html_to_open_graph(tree)
self.assertEqual(og, {"og:title": "ó", "og:description": "Some text."})
@ -380,6 +393,7 @@ class OpenGraphFromHtmlTestCase(unittest.TestCase):
</html>
"""
tree = decode_body(html, "http://example.com/test.html")
assert tree is not None
og = parse_html_to_open_graph(tree)
self.assertEqual(
og,
@ -401,6 +415,7 @@ class OpenGraphFromHtmlTestCase(unittest.TestCase):
</html>
"""
tree = decode_body(html, "http://example.com/test.html")
assert tree is not None
og = parse_html_to_open_graph(tree)
self.assertEqual(
og,
@ -419,6 +434,7 @@ class OpenGraphFromHtmlTestCase(unittest.TestCase):
with a cheeky SVG</svg></u> and <strong>some</strong> tail text</b></a>
"""
tree = decode_body(html, "http://example.com/test.html")
assert tree is not None
og = parse_html_to_open_graph(tree)
self.assertEqual(
og,

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@ -28,7 +28,7 @@ from tests.unittest import HomeserverTestCase
try:
import lxml
except ImportError:
lxml = None
lxml = None # type: ignore[assignment]
class OEmbedTests(HomeserverTestCase):

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@ -24,7 +24,7 @@ from tests.unittest import override_config
try:
import lxml
except ImportError:
lxml = None
lxml = None # type: ignore[assignment]
class URLPreviewTests(unittest.HomeserverTestCase):

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@ -40,7 +40,7 @@ from tests.test_utils import SMALL_PNG
try:
import lxml
except ImportError:
lxml = None
lxml = None # type: ignore[assignment]
class URLPreviewTests(unittest.HomeserverTestCase):