test_gzip_cache.py

# -*- coding: utf-8 -*-
'''Core plugins unit tests'''

import os
import tempfile
import unittest
import time

from contextlib import contextmanager
from tempfile import mkdtemp
from shutil import rmtree
from hashlib import md5

import gzip_cache

@contextmanager
def temporary_folder():
    """creates a temporary folder, return it and delete it afterwards.

    This allows to do something like this in tests:

        >>> with temporary_folder() as d:
            # do whatever you want
    """
    tempdir = mkdtemp()
    try:
        yield tempdir
    finally:
        rmtree(tempdir)


class TestGzipCache(unittest.TestCase):

    def test_should_compress(self):
        user_exclude_types = ()

        # Some filetypes should compress and others shouldn't.
        self.assertTrue(gzip_cache.should_compress('foo.html', user_exclude_types))
        self.assertTrue(gzip_cache.should_compress('bar.css', user_exclude_types))
        self.assertTrue(gzip_cache.should_compress('baz.js', user_exclude_types))
        self.assertTrue(gzip_cache.should_compress('foo.txt', user_exclude_types))

        self.assertFalse(gzip_cache.should_compress('foo.gz', user_exclude_types))
        self.assertFalse(gzip_cache.should_compress('bar.png', user_exclude_types))
        self.assertFalse(gzip_cache.should_compress('baz.mp3', user_exclude_types))
        self.assertFalse(gzip_cache.should_compress('foo.mov', user_exclude_types))

        user_exclude_types = ('.html', '.xyz')
        self.assertFalse(gzip_cache.should_compress('foo.html', user_exclude_types))
        self.assertFalse(gzip_cache.should_compress('bar.xyz', user_exclude_types))
        self.assertFalse(gzip_cache.should_compress('foo.gz', user_exclude_types))
        self.assertTrue(gzip_cache.should_compress('baz.js', user_exclude_types))

    def test_should_overwrite(self):
        # Default to false if GZIP_CACHE_OVERWRITE is not set
        settings = { }
        self.assertFalse(gzip_cache.should_overwrite(settings))
        settings = { 'GZIP_CACHE_OVERWRITE': False }
        self.assertFalse(gzip_cache.should_overwrite(settings))
        settings = { 'GZIP_CACHE_OVERWRITE': True }
        self.assertTrue(gzip_cache.should_overwrite(settings))

    def test_creates_gzip_file(self):
        # A file matching the input filename with a .gz extension is created.

        # The plugin walks over the output content after the finalized signal
        # so it is safe to assume that the file exists (otherwise walk would
        # not report it). Therefore, create a dummy file to use.
        with temporary_folder() as tempdir:
            _, a_html_filename = tempfile.mkstemp(suffix='.html', dir=tempdir)
            with open(a_html_filename, 'w') as f:
                f.write('A' * 24)  # under this length, compressing is useless and create_gzip_file will not create any file
            gzip_cache.create_gzip_file(a_html_filename, False)
            self.assertTrue(os.path.exists(a_html_filename + '.gz'))

    def test_creates_same_gzip_file(self):
        # Should create the same gzip file from the same contents.

        # gzip will create a slightly different file because it includes
        # a timestamp in the compressed file by default. This can cause
        # problems for some caching strategies.
        with temporary_folder() as tempdir:
            _, a_html_filename = tempfile.mkstemp(suffix='.html', dir=tempdir)
            with open(a_html_filename, 'w') as f:
                f.write('A' * 24)  # under this length, compressing is useless and create_gzip_file will not create any file
            a_gz_filename = a_html_filename + '.gz'
            gzip_cache.create_gzip_file(a_html_filename, False)
            gzip_hash = get_md5(a_gz_filename)
            time.sleep(1)
            gzip_cache.create_gzip_file(a_html_filename, False)
            self.assertEqual(gzip_hash, get_md5(a_gz_filename))

    def test_overwrites_gzip_file(self):
        # A file matching the input filename with a .gz extension is not created.

        # The plugin walks over the output content after the finalized signal
        # so it is safe to assume that the file exists (otherwise walk would
        # not report it). Therefore, create a dummy file to use.
        with temporary_folder() as tempdir:
            _, a_html_filename = tempfile.mkstemp(suffix='.html', dir=tempdir)
            gzip_cache.create_gzip_file(a_html_filename, True)
            self.assertFalse(os.path.exists(a_html_filename + '.gz'))

def get_md5(filepath):
    with open(filepath, 'rb') as fh:
        return md5(fh.read()).hexdigest()