WeasyPrint/weasy/tests/css.py

# coding: utf8

#  WeasyPrint converts web documents (HTML, CSS, ...) to PDF.
#  Copyright (C) 2011  Simon Sapin
#
#  This program is free software: you can redistribute it and/or modify
#  it under the terms of the GNU Affero General Public License as
#  published by the Free Software Foundation, either version 3 of the
#  License, or (at your option) any later version.
#
#  This program is distributed in the hope that it will be useful,
#  but WITHOUT ANY WARRANTY; without even the implied warranty of
#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#  GNU Affero General Public License for more details.
#
#  You should have received a copy of the GNU Affero General Public License
#  along with this program.  If not, see <http://www.gnu.org/licenses/>.

from attest import Tests, assert_hook
from lxml import html
#from lxml.html import html5parser as html  # API is the same as lxml.html
import cssutils
from cssutils.helper import path2url

from .. import css

from . import resource_filename


suite = Tests()

def parse_html(filename):
    """Parse an HTML file from the test resources and resolve relative URL."""
    document = html.parse(path2url(resource_filename(filename))).getroot()
    document.make_links_absolute()
    return document


@suite.test
def test_find_stylesheets():
    document = parse_html('doc1.html')
    
    sheets = list(css.find_stylesheets(document))
    assert len(sheets) == 2
    assert set(s.href.rsplit('/', 1)[-1] for s in sheets) == set(
        ['doc1.html', 'sheet1.css'])

    rules = list(rule for sheet in sheets
                      for rule in css.resolve_import_media(sheet, 'print'))
    assert len(rules) == 5
    assert set(rule.selectorText for rule in rules) == set(
        ['p', 'ul', 'li', 'a', ':first'])


@suite.test
def test_expand_shorthands():
    sheet = cssutils.parseFile(resource_filename('sheet2.css'))
    assert sheet.cssRules[0].selectorText == 'li'
    style = sheet.cssRules[0].style
    assert style['margin'] == '2em 0'
    assert style['margin-bottom'] == '3em'
    assert style['margin-left'] == '4em'
    assert not style['margin-top']
    css.expand_shorthands(sheet)
    # expand_shorthands() builds new style object
    style = sheet.cssRules[0].style
    assert not style['margin']
    assert style['margin-top'] == '2em'
    assert style['margin-right'] == '0'
    assert style['margin-bottom'] == '2em', \
        "3em was before the shorthand, should be masked"
    assert style['margin-left'] == '4em', \
        "4em was after the shorthand, should not be masked"


def get_value(property_or_list):
    if hasattr(property_or_list, 'value'):
        return property_or_list.value
    else:
        return ' '.join(p.cssText for p in property_or_list)

@suite.test
def test_annotate_document():
    user_stylesheet = cssutils.parseFile(resource_filename('user.css'))
    ua_stylesheet = cssutils.parseFile(resource_filename('mini_ua.css'))
    document = parse_html('doc1.html')
    
    css.annotate_document(document, [user_stylesheet], [ua_stylesheet])
    
    # Element objects behave a lists of their children
    head, body = document
    p, ul = body
    li = list(ul)
    a, = li[0]
    
    sides = ('-top', '-right', '-bottom', '-left')
    # 32px = 1em * font-size: 2em * initial 16px
    for side, expected_value in zip(sides, ('32px', '0', '32px', '0')):
        assert get_value(p.style['margin' + side]) == expected_value
    
    # 32px = 2em * initial 16px
    for side, expected_value in zip(sides, ('32px', '32px', '32px', '32px')):
        assert get_value(ul.style['margin' + side]) == expected_value
    
    # 32px = 2em * initial 16px
    # 64px = 4em * initial 16px
    for side, expected_value in zip(sides, ('32px', '0', '32px', '64px')):
        assert get_value(li[0].style['margin' + side]) == expected_value
    
    assert get_value(a.style['text-decoration']) == 'underline'
    assert get_value(a.style['color']) == 'red'
    # TODO much more tests here: test that origin and selector precedence
    # and inheritance are correct, ...