Non-deterministic provider output

[covracer]

Thanks for the awesome software! Something I ran into while trying to automate managing user accounts across providers:

test.py:

import json
from terraformpy import Provider, compile
with Provider("github", alias="github"):
    pass
with Provider("aws", alias="aws"):
    pass
print(json.dumps(compile(), sort_keys=True))

$ for i in $(seq 10); do python test.py; done
{"provider": {"aws": {"alias": "aws"}, "github": {"alias": "github"}}}
{"provider": {"aws": {"alias": "aws"}, "github": {"alias": "github"}}}
{"provider": {"github": {"alias": "github"}, "aws": {"alias": "aws"}}}
{"provider": {"aws": {"alias": "aws"}, "github": {"alias": "github"}}}
{"provider": {"aws": {"alias": "aws"}, "github": {"alias": "github"}}}
{"provider": {"github": {"alias": "github"}, "aws": {"alias": "aws"}}}
{"provider": {"github": {"alias": "github"}, "aws": {"alias": "aws"}}}
{"provider": {"github": {"alias": "github"}, "aws": {"alias": "aws"}}}
{"provider": {"github": {"alias": "github"}, "aws": {"alias": "aws"}}}
{"provider": {"github": {"alias": "github"}, "aws": {"alias": "aws"}}}

It seems like this is because of how the comparison dunder methods in terraformpy.objects.DuplicateKey use the hash:

terraformpy/src/terraformpy/objects.py

Lines 66 to 87 in a15ee95

	def __eq__(self, other):
	return self.__class__ == other.__class__ and self._hash == other._hash
	def __lt__(self, other):
	if self.__class__ == other.__class__:
	return self._hash < other._hash
	return super(DuplicateKey, self).__lt__(other)
	def __le__(self, other):
	if self.__class__ == other.__class__:
	return self._hash <= other._hash
	return super(DuplicateKey, self).__le__(other)
	def __gt__(self, other):
	if self.__class__ == other.__class__:
	return self._hash > other._hash
	return super(DuplicateKey, self).__gt__(other)
	def __ge__(self, other):
	if self.__class__ == other.__class__:
	return self._hash >= other._hash
	return super(DuplicateKey, self).__ge__(other)

In the specific case of providers, it crossed my mind that sorting by alias could be appropriate. But maybe DuplicateKey is used in other situations where there isn't a good field to sort on?

In looking into the Terraform/duplicate key JSON side of the issue, I learned that a JSON array of objects is also accepted.

So here's my current workaround (which relies on the Python 3.7+ dictionary insertion order guarantee):

dictionaries = compile()
provider_items = dictionaries["provider"].items()
if len(provider_items) > 1:
    assert sys.version_info >= (3, 7)
    provider_list = [{str(key): value} for key, value in provider_items]
    dictionaries["provider"] = provider_list