test_graphviz.py

# -*- coding: utf-8 -*-
"""Unit testing suite for the Graphviz plugin"""

## Copyright (C) 2015, 2021  Rafael Laboissiere <rafael@laboissiere.net>
##
## This program is free software: you can redistribute it and/or modify it
## under the terms of the GNU General Affero 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/.

import os
import re
import unittest
from tempfile import mkdtemp
from shutil import rmtree

from . import *
from pelican import Pelican
from pelican.settings import read_settings


TEST_FILE_STEM = 'test'
TEST_DIR_PREFIX = 'pelicantests.'
GRAPHVIZ_RE = '<div class="%s"><img src="data:image/svg\+xml;base64,[0-9a-zA-Z+/]+" /></div>'

class TestGraphviz (unittest.TestCase):
    """Class for testing the URL output of the Graphviz plugin"""

    def setUp (self, block_start = '..graphviz', image_class = 'graphviz'):

        ## Set the paths for the input (content) and output (html) files
        self.output_path = mkdtemp (prefix = TEST_DIR_PREFIX)
        self.content_path = mkdtemp (prefix = TEST_DIR_PREFIX)

        ## Configuration setting for the Pelican process
        settings = {
            'PATH': self.content_path,
            'OUTPUT_PATH': self.output_path,
            'PLUGINS': [graphviz],
            'CACHE_CONTENT': False,
            'GRAPHVIZ_BLOCK_START': block_start,
            'GRAPHVIZ_IMAGE_CLASS': image_class
        }

        ## Store the image_class in self, since it will be needed in the
        ## test_output method defined below
        self.image_class = image_class

        ## Create the article file
        fid = open (os.path.join (self.content_path, '%s.md' % TEST_FILE_STEM),
                    'w')
        ## Write header
        fid.write ('Title: %s\nDate:\n' % TEST_FILE_STEM)
        ## Write Graphviz block
        fid.write ('''
%s dot
digraph G {
  graph [rankdir = LR];
  Hello -> World
}


''' % block_start)
        fid.close ()

        ## Run the Pelican instance
        self.settings = read_settings (override = settings)
        pelican = Pelican (settings = self.settings)
        pelican.run ()

    def tearDown (self):
        """Clean up the temporary directories"""
        rmtree (self.output_path)
        rmtree (self.content_path)

    def test_output (self):
        """Test for default values of the configuration variables"""
        ## Open the output HTML file
        fid = open (os.path.join (self.output_path, '%s.html' % TEST_FILE_STEM),
                    'r')
        found = False
        ## Iterate over the lines and look for the HTML element corresponding
        ## to the generated Graphviz figure
        for line in fid.readlines ():
            if re.search (GRAPHVIZ_RE % self.image_class, line):
                found = True
                break
        assert found


class TestGraphvizBlockStart (TestGraphviz):
    """Class for exercising the configuration variable GRAPHVIZ_BLOCK_START"""

    def setUp (self):
        """Initialize the configuration"""
        TestGraphviz.setUp (self, block_start = '==foobar')

    def test_output (self):
        """Test for GRAPHVIZ_BLOCK_START setting"""
        TestGraphviz.test_output (self)


class TestGraphvizImageClass (TestGraphviz):
    """Class for exercising configuration variable GRAPHVIZ_IMAGE_CLASS"""

    def setUp (self):
        """Initialize the configuration"""
        TestGraphviz.setUp (self, image_class = 'foo')

    def test_output (self):
        """Test for GRAPHVIZ_IMAGE_CLASS setting"""
        TestGraphviz.test_output (self)