Files
tubestation/taskcluster/taskgraph/parameters.py
Gregory Szorc 5fe1f3f6e3 Bug 1295486 - Decode YAML files to UTF-8 at read time; r=dustin
Before, we'd open files and feed bytes to yaml.load(). When a str
is fed to yaml.load(), it attempts to guess the encoding. It defaults
to UTF-8 unless somebody set us up the BOM. This is probably OK.
Except if the file isn't valid UTF-8, the exception will be raised
in the bowels of YAML parsing and it may not be obvious the failure
is due to invalid UTF-8 input versus say Python str/unicode
coercion foo.

We change all call sites that load YAML from a file to use
codecs.open() to open the file in UTF-8 and perform UTF-8
decoding/validation at file read time. This should make any UTF-8
failures more obvious. Furthermore, it reinforces that our YAML files
are UTF-8 and not some other encoding.

I discovered this issue as part of trying to get emoji symbols to
render on Treeherder. Unfortunately, it appears pyyaml detects
many emoji as unprintable characters and refuses to load them. This
makes me sad and makes me want to abandon pyyaml/YAML in favor of
something that supports emoji :P

MozReview-Commit-ID: AOvAruZFfnK
2016-08-18 08:58:59 -07:00

38 lines
1.2 KiB
Python

# -*- coding: utf-8 -*-
# This Source Code Form is subject to the terms of the Mozilla Public
# License, v. 2.0. If a copy of the MPL was not distributed with this
# file, You can obtain one at http://mozilla.org/MPL/2.0/.
from __future__ import absolute_import, print_function, unicode_literals
import codecs
import json
import yaml
from mozbuild.util import ReadOnlyDict
class Parameters(ReadOnlyDict):
"""An immutable dictionary with nicer KeyError messages on failure"""
def __getitem__(self, k):
try:
return super(Parameters, self).__getitem__(k)
except KeyError:
raise KeyError("taskgraph parameter {!r} not found".format(k))
def load_parameters_file(options):
"""
Load parameters from the --parameters option
"""
filename = options['parameters']
if not filename:
return Parameters()
with codecs.open(filename, 'rb', 'utf-8') as f:
if filename.endswith('.yml'):
return Parameters(**yaml.safe_load(f))
elif filename.endswith('.json'):
return Parameters(**json.load(f))
else:
raise TypeError("Parameters file `{}` is not JSON or YAML".format(filename))