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#!/usr/bin/env python
# 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,
import json
import re
import sys
import toml
import voluptuous
import voluptuous.humanize
from voluptuous import Schema, Optional, Any, All, Required, Length, Range, Msg, Match
Text = Any(str, bytes)
id_regex = re.compile(r"^[a-z0-9-]+$")
feature_schema = Schema(
{
Match(id_regex): {
Required("group"): All(Text, Length(min=1)),
Required("title"): All(Text, Length(min=1)),
Required("description"): All(Text, Length(min=1)),
Required("bug-numbers"): All(Length(min=1), [All(int, Range(min=1))]),
Required("restart-required"): bool,
Required("type"): "boolean", # In the future this may include other types
Optional("preference"): Text,
Optional("default-value-jexl"): Text,
Optional("is-public-jexl"): Text,
Optional("description-links"): dict,
},
}
)
EXIT_OK = 0
EXIT_ERROR = 1
def main(output, *filenames):
features = {}
errors = False
try:
features = process_files(filenames)
json.dump(features, output)
except ExceptionGroup as error_group:
print(str(error_group))
return EXIT_ERROR
return EXIT_OK
class ExceptionGroup(Exception):
def __init__(self, errors):
self.errors = errors
def __str__(self):
rv = ["There were errors while processing feature definitions:"]
for error in self.errors:
# indent the message
s = "\n".join(" " + line for line in str(error).split("\n"))
# add a * at the beginning of the first line
s = " * " + s[4:]
rv.append(s)
return "\n".join(rv)
class FeatureGateException(Exception):
def __init__(self, message, filename=None):
super(FeatureGateException, self).__init__(message)
self.filename = filename
def __str__(self):
message = super(FeatureGateException, self).__str__()
rv = ["In"]
if self.filename is None:
rv.append("unknown file:")
else:
rv.append('file "{}":\n'.format(self.filename))
rv.append(message)
return " ".join(rv)
def __repr__(self):
# Turn "FeatureGateExcept(<message>,)" into "FeatureGateException(<message>, filename=<filename>)"
original = super(FeatureGateException, self).__repr__()
with_comma = original[:-1]
# python 2 adds a trailing comma and python 3 does not, so we need to conditionally reinclude it
if len(with_comma) > 0 and with_comma[-1] != ",":
with_comma = with_comma + ","
return with_comma + " filename={!r})".format(self.filename)
def process_files(filenames):
features = {}
errors = []
for filename in filenames:
try:
with open(filename, "r") as f:
feature_data = toml.load(f)
voluptuous.humanize.validate_with_humanized_errors(
feature_data, feature_schema
)
for feature_id, feature in feature_data.items():
feature["id"] = feature_id
features[feature_id] = expand_feature(feature)
except (
voluptuous.error.Error,
IOError,
FeatureGateException,
toml.TomlDecodeError,
) as e:
# Wrap errors in enough information to know which file they came from
errors.append(FeatureGateException(e, filename))
if errors:
raise ExceptionGroup(errors)
return features
def hyphens_to_camel_case(s):
"""Convert names-with-hyphens to namesInCamelCase"""
rv = ""
for part in s.split("-"):
if rv == "":
rv = part.lower()
else:
rv += part[0].upper() + part[1:].lower()
return rv
def expand_feature(feature):
"""Fill in default values for optional fields"""
# convert all names-with-hyphens to namesInCamelCase
key_changes = []
for key in feature.keys():
if "-" in key:
new_key = hyphens_to_camel_case(key)
key_changes.append((key, new_key))
for old_key, new_key in key_changes:
feature[new_key] = feature[old_key]
del feature[old_key]
if feature["type"] == "boolean":
feature.setdefault("preference", "features.{}.enabled".format(feature["id"]))
# set default value to None so that we can test for preferences where we forgot to set the default value
feature.setdefault("defaultValueJexl", None)
elif "preference" not in feature:
raise FeatureGateException(
"Features of type {} must specify an explicit preference name".format(
feature["type"]
)
)
feature.setdefault("isPublicJexl", "false")
return feature
if __name__ == "__main__":
sys.exit(main(sys.stdout, *sys.argv[1:]))