def test_next_backup_filename():
"""Test generating the next backup file name"""
assert next_backup_filename('foo', ['a', 'b']) == 'foo~'
assert next_backup_filename('foo', ['a', 'b', 'foo']) == 'foo~'
assert next_backup_filename('foo', ['a', 'b', 'foo~']) == 'foo1~'
assert next_backup_filename('foo', ['a', 'b', 'foo', 'foo~']) == 'foo1~'
assert next_backup_filename('foo', ['a', 'b', 'foo~', 'foo1~']) == 'foo2~'
assert next_backup_filename('foo', ['a', 'b', 'foo~', 'foo1~', 'foo3~']) == 'foo4~'
assert next_backup_filename('foo', ['a', 'b', 'foo', 'foo1~', 'foo3~']) == 'foo~'
def _create_from_template(self, src_filename, dest_filename, **kwargs):
"""
Render the destination file from the source template file
Scans the templates directory and create any corresponding files relative
to the root directory. If the file is a .template, then renders the file,
else simply copy it.
Template files are just string templates which will be formatted with the
following named arguments: name, package, author, author_email, and description.
Note, be sure to escape curly brackets ('{', '}') with double curly brackets ('{{', '}}').
:param src_filename: the template file
:param dest_filename: the rendered file
"""
info("creating {dest} from {src}".format(dest=dest_filename, src=src_filename))
with open(src_filename) as in_file:
template = in_file.read()
new_filename = None
try:
# we just want the unique temp file name, we will delete it in the finally block
tf = tempfile.NamedTemporaryFile(delete=False)
new_filename = tf.name
tf.close()
rendered = template.format(**kwargs)
with open(new_filename, 'w') as out_file:
try:
out_file.write(rendered)
# catching all exceptions
# pylint: disable=W0703
except Exception as ex:
error(ex)
# if there is a dest_filename, then handle backing it up
if os.path.isfile(dest_filename):
# new_filename contains the just rendered template
# dest_filename contains the original content
# if new_filename contents equal dest_filename contents, then we are done
if md5sum(new_filename)[0] == md5sum(dest_filename)[0]:
return
# new_filename content and dest_filename content differ
# so if there is a backup file and if the backup file contents diff from the dest_filename contents,
# then we rename the dest_filename to then incremented backup_filename (one past the highest
# existing value)
backup_filename = next_backup_filename(name=dest_filename)
os.rename(dest_filename, backup_filename)
# next we remove the dest_filename then move new_filename to dest_filename
if os.path.isfile(dest_filename):
os.remove(dest_filename)
shutil.copyfile(new_filename, dest_filename)
except Exception as ex:
error("Error rendering template ({file}) - {err}\n{trace}".format(file=src_filename,
err=str(ex),
trace=traceback.format_exc()))
error("kwargs:\n{kwargs}".format(kwargs=pformat(kwargs)))
finally:
if new_filename is not None:
if os.path.isfile(new_filename):
os.remove(new_filename)
