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breadability/tests/test_scoring.py

296 lines
8.8 KiB
Python

# -*- coding: utf8 -*-
from __future__ import absolute_import, division, print_function, unicode_literals
import re
from operator import attrgetter
from lxml.html import document_fromstring, fragment_fromstring
from breadability.readable import Article, get_link_density, is_unlikely_node
from breadability.scoring import (ScoredNode, check_node_attributes, generate_hash_id, get_class_weight,
score_candidates)
from .utils import load_snippet
def test_generate_hash():
dom = fragment_fromstring("<div>ľščťžýáí</div>")
generate_hash_id(dom)
def test_hash_from_id_on_exception():
generate_hash_id(None)
def test_different_hashes():
dom = fragment_fromstring("<div>ľščťžýáí</div>")
hash_dom = generate_hash_id(dom)
hash_none = generate_hash_id(None)
assert hash_dom != hash_none
def test_equal_hashes():
dom1 = fragment_fromstring("<div>ľščťžýáí</div>")
dom2 = fragment_fromstring("<div>ľščťžýáí</div>")
hash_dom1 = generate_hash_id(dom1)
hash_dom2 = generate_hash_id(dom2)
assert hash_dom1 == hash_dom2
hash_none1 = generate_hash_id(None)
hash_none2 = generate_hash_id(None)
assert hash_none1 == hash_none2
# Verify a node has a class/id in the given set.
# The idea is that we have sets of known good/bad ids and classes and need
# to verify the given node does/doesn't have those classes/ids.
def test_has_class():
"""Verify that a node has a class in our set."""
test_pattern = re.compile('test1|test2', re.I)
test_node = fragment_fromstring('<div/>')
test_node.set('class', 'test2 comment')
assert check_node_attributes(test_pattern, test_node, 'class')
def test_has_id():
"""Verify that a node has an id in our set."""
test_pattern = re.compile('test1|test2', re.I)
test_node = fragment_fromstring('<div/>')
test_node.set('id', 'test2')
assert check_node_attributes(test_pattern, test_node, 'id')
def test_lacks_class():
"""Verify that a node does not have a class in our set."""
test_pattern = re.compile('test1|test2', re.I)
test_node = fragment_fromstring('<div/>')
test_node.set('class', 'test4 comment')
assert not check_node_attributes(test_pattern, test_node, 'class')
def test_lacks_id():
"""Verify that a node does not have an id in our set."""
test_pattern = re.compile('test1|test2', re.I)
test_node = fragment_fromstring('<div/>')
test_node.set('id', 'test4')
assert not check_node_attributes(test_pattern, test_node, 'id')
# Verify we calc our link density correctly.
def test_empty_node():
"""An empty node doesn't have much of a link density"""
doc = Article("<div></div>")
assert get_link_density(doc.readable_dom) == 0.0
def test_small_doc_no_links():
doc = Article(load_snippet('document_min.html'))
assert get_link_density(doc.readable_dom) == 0.0
def test_several_links():
"""This doc has a 3 links with the majority of content."""
doc = Article(load_snippet('document_absolute_url.html'))
assert get_link_density(doc.readable_dom) == 22/37
# Verify we score nodes correctly based on their class/id attributes.
def test_no_matches_zero():
"""If you don't have the attribute then you get a weight of 0"""
node = fragment_fromstring("<div></div>")
assert get_class_weight(node) == 0
def test_id_hits():
"""If the id is in the list then it gets a weight"""
test_div = '<div id="post">Content</div>'
node = fragment_fromstring(test_div)
assert get_class_weight(node) == 25
test_div = '<div id="comments">Content</div>'
node = fragment_fromstring(test_div)
assert get_class_weight(node) == -25
def test_class_hits():
"""If the class is in the list then it gets a weight"""
test_div = '<div class="something post">Content</div>'
node = fragment_fromstring(test_div)
assert get_class_weight(node) == 25
test_div = '<div class="something comments">Content</div>'
node = fragment_fromstring(test_div)
assert get_class_weight(node) == -25
def test_scores_collide():
"""We might hit both positive and negative scores.
Positive and negative scoring is done independently so it's possible
to hit both positive and negative scores and cancel each other out.
"""
test_div = '<div id="post" class="something comment">Content</div>'
node = fragment_fromstring(test_div)
assert get_class_weight(node) == 0
test_div = '<div id="post" class="post comment">Content</div>'
node = fragment_fromstring(test_div)
assert get_class_weight(node) == 25
def test_scores_only_once():
"""Scoring is not cumulative within a class hit."""
test_div = '<div class="post main">Content</div>'
node = fragment_fromstring(test_div)
assert get_class_weight(node) == 25
# is_unlikely_node should help verify our node is good/bad.
def test_body_is_always_likely():
"""The body tag is always a likely node."""
test_div = '<body class="comment"><div>Content</div></body>'
node = fragment_fromstring(test_div)
assert not is_unlikely_node(node)
def test_is_unlikely():
"""Keywords in the class/id will make us believe this is unlikely."""
test_div = '<div class="something comments">Content</div>'
node = fragment_fromstring(test_div)
assert is_unlikely_node(node)
test_div = '<div id="comments">Content</div>'
node = fragment_fromstring(test_div)
assert is_unlikely_node(node)
def test_not_unlikely():
"""Suck it double negatives."""
test_div = '<div id="post">Content</div>'
node = fragment_fromstring(test_div)
assert not is_unlikely_node(node)
test_div = '<div class="something post">Content</div>'
node = fragment_fromstring(test_div)
assert not is_unlikely_node(node)
def test_maybe_hits():
"""We've got some maybes that will overrule an unlikely node."""
test_div = '<div id="comments" class="article">Content</div>'
node = fragment_fromstring(test_div)
assert not is_unlikely_node(node)
# ScoredNodes constructed have initial content_scores, etc.
def test_hash_id():
"""ScoredNodes have a hash_id based on their content
Since this is based on the html there are chances for collisions, but
it helps us follow and identify nodes through the scoring process. Two
identical nodes would score the same, so meh all good.
"""
test_div = '<div id="comments" class="article">Content</div>'
node = fragment_fromstring(test_div)
snode = ScoredNode(node)
assert snode.hash_id == 'ffa4c519'
def test_div_content_score():
"""A div starts out with a score of 5 and modifies from there"""
test_div = '<div id="" class="">Content</div>'
node = fragment_fromstring(test_div)
snode = ScoredNode(node)
assert snode.content_score == 5
test_div = '<div id="article" class="">Content</div>'
node = fragment_fromstring(test_div)
snode = ScoredNode(node)
assert snode.content_score == 30
test_div = '<div id="comments" class="">Content</div>'
node = fragment_fromstring(test_div)
snode = ScoredNode(node)
assert snode.content_score == -20
def test_headings_score():
"""Heading tags aren't likely candidates, hurt their scores."""
test_div = '<h2>Heading</h2>'
node = fragment_fromstring(test_div)
snode = ScoredNode(node)
assert snode.content_score == -5
def test_list_items():
"""Heading tags aren't likely candidates, hurt their scores."""
test_div = '<li>list item</li>'
node = fragment_fromstring(test_div)
snode = ScoredNode(node)
assert snode.content_score == -3
# The grand daddy of tests to make sure our scoring works
# Now scoring details will change over time, so the most important thing is
# to make sure candidates come out in the right order, not necessarily how
# they scored. Make sure to keep this in mind while getting tests going.
def test_simple_candidate_set():
"""Tests a simple case of two candidate nodes"""
html = """
<html>
<body>
<div class="content">
<p>This is a great amount of info</p>
<p>And more content <a href="/index">Home</a>
</div>
<div class="footer">
<p>This is a footer</p>
<p>And more content <a href="/index">Home</a>
</div>
</body>
</html>
"""
dom = document_fromstring(html)
div_nodes = dom.findall(".//div")
candidates = score_candidates(div_nodes)
ordered = sorted(
(c for c in candidates.values()), reverse=True,
key=attrgetter("content_score"))
assert ordered[0].node.tag == "div"
assert ordered[0].node.attrib["class"] == "content"
assert ordered[1].node.tag == "body"
assert ordered[2].node.tag == "html"
assert ordered[3].node.tag == "div"
assert ordered[3].node.attrib["class"] == "footer"