gecko-dev/taskcluster/taskgraph/util/templates.py
Justin Wood 94d4e53251 Bug 1352113 - Shippable Builds - Do not run merge on by-* values. r=tomprince
This was needed since when we have job-defaults and later on a test set for
``
run-on-projects:
    by-test-platform:
        ...
``
We were ending up with both the list of by-* being extended but also
any array in that list also being extended (like `default: ['a', 'b']`
was getting extended to also have the new values for default)

This is not only usually wrong but very very likely not what the author wanted.

Differential Revision: https://phabricator.services.mozilla.com/D22708

--HG--
extra : moz-landing-system : lando
2019-03-22 03:22:42 +00:00

57 lines
1.7 KiB
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, You can obtain one at http://mozilla.org/MPL/2.0/.
from __future__ import absolute_import, print_function, unicode_literals
import copy
def merge_to(source, dest):
'''
Merge dict and arrays (override scalar values)
Keys from source override keys from dest, and elements from lists in source
are appended to lists in dest.
:param dict source: to copy from
:param dict dest: to copy to (modified in place)
'''
for key, value in source.items():
if isinstance(value, dict) and len(value) == 1 and \
value.keys()[0].startswith('by-'):
# Do not merge by-* values as this is likely to confuse someone
dest[key] = value
continue
# Override mismatching or empty types
if type(value) != type(dest.get(key)): # noqa
dest[key] = source[key]
continue
# Merge dict
if isinstance(value, dict):
merge_to(value, dest[key])
continue
if isinstance(value, list):
dest[key] = dest[key] + source[key]
continue
dest[key] = source[key]
return dest
def merge(*objects):
'''
Merge the given objects, using the semantics described for merge_to, with
objects later in the list taking precedence. From an inheritance
perspective, "parents" should be listed before "children".
Returns the result without modifying any arguments.
'''
if len(objects) == 1:
return copy.deepcopy(objects[0])
return merge_to(objects[-1], merge(*objects[:-1]))