ansible/test/units/mock/yaml_helper.py

import io
import yaml

from ansible.parsing.yaml.loader import AnsibleLoader
from ansible.parsing.yaml.dumper import AnsibleDumper

from ansible.compat.six import PY3

class YamlTestUtils(object):
    """Mixin class to combine with a unittest.TestCase subclass."""
    def _loader(self, stream):
        """Vault related tests will want to override this.

        Vault cases should setup a AnsibleLoader that has the vault password."""
        return AnsibleLoader(stream)

    def _dump_stream(self, obj, stream, dumper=None):
        """Dump to a py2-unicode or py3-string stream."""
        if PY3:
            return yaml.dump(obj, stream, Dumper=dumper)
        else:
            return yaml.dump(obj, stream, Dumper=dumper, encoding=None)

    def _dump_string(self, obj, dumper=None):
        """Dump to a py2-unicode or py3-string"""
        if PY3:
            return yaml.dump(obj, Dumper=dumper)
        else:
            return yaml.dump(obj, Dumper=dumper, encoding=None)

    def _dump_load_cycle(self, obj):
        # Each pass though a dump or load revs the 'generation'
        # obj to yaml string
        string_from_object_dump = self._dump_string(obj, dumper=AnsibleDumper)

        # wrap a stream/file like StringIO around that yaml
        stream_from_object_dump = io.StringIO(string_from_object_dump)
        loader = self._loader(stream_from_object_dump)
        # load the yaml stream to create a new instance of the object (gen 2)
        obj_2 = loader.get_data()

        # dump the gen 2 objects directory to strings
        string_from_object_dump_2 = self._dump_string(obj_2,
                                                      dumper=AnsibleDumper)

        # The gen 1 and gen 2 yaml strings
        self.assertEquals(string_from_object_dump, string_from_object_dump_2)
        # the gen 1 (orig) and gen 2 py object
        self.assertEquals(obj, obj_2)

        # again! gen 3... load strings into py objects
        stream_3 = io.StringIO(string_from_object_dump_2)
        loader_3 = self._loader(stream_3)
        obj_3 = loader_3.get_data()

        string_from_object_dump_3 = self._dump_string(obj_3, dumper=AnsibleDumper)

        self.assertEquals(obj, obj_3)
        # should be transitive, but...
        self.assertEquals(obj_2, obj_3)
        self.assertEquals(string_from_object_dump, string_from_object_dump_3)

    def _old_dump_load_cycle(self, obj):
        '''Dump the passed in object to yaml, load it back up, dump again, compare.'''
        stream = io.StringIO()

        yaml_string = self._dump_string(obj, dumper=AnsibleDumper)
        self._dump_stream(obj, stream, dumper=AnsibleDumper)

        yaml_string_from_stream = stream.getvalue()

        # reset stream
        stream.seek(0)

        loader = self._loader(stream)
        # loader = AnsibleLoader(stream, vault_password=self.vault_password)
        obj_from_stream = loader.get_data()

        stream_from_string = io.StringIO(yaml_string)
        loader2 = self._loader(stream_from_string)
        # loader2 = AnsibleLoader(stream_from_string, vault_password=self.vault_password)
        obj_from_string = loader2.get_data()

        stream_obj_from_stream = io.StringIO()
        stream_obj_from_string = io.StringIO()

        if PY3:
            yaml.dump(obj_from_stream, stream_obj_from_stream, Dumper=AnsibleDumper)
            yaml.dump(obj_from_stream, stream_obj_from_string, Dumper=AnsibleDumper)
        else:
            yaml.dump(obj_from_stream, stream_obj_from_stream, Dumper=AnsibleDumper, encoding=None)
            yaml.dump(obj_from_stream, stream_obj_from_string, Dumper=AnsibleDumper, encoding=None)

        yaml_string_stream_obj_from_stream = stream_obj_from_stream.getvalue()
        yaml_string_stream_obj_from_string = stream_obj_from_string.getvalue()

        stream_obj_from_stream.seek(0)
        stream_obj_from_string.seek(0)

        if PY3:
            yaml_string_obj_from_stream = yaml.dump(obj_from_stream, Dumper=AnsibleDumper)
            yaml_string_obj_from_string = yaml.dump(obj_from_string, Dumper=AnsibleDumper)
        else:
            yaml_string_obj_from_stream = yaml.dump(obj_from_stream, Dumper=AnsibleDumper, encoding=None)
            yaml_string_obj_from_string = yaml.dump(obj_from_string, Dumper=AnsibleDumper, encoding=None)

        assert yaml_string == yaml_string_obj_from_stream
        assert yaml_string == yaml_string_obj_from_stream == yaml_string_obj_from_string
        assert (yaml_string == yaml_string_obj_from_stream == yaml_string_obj_from_string == yaml_string_stream_obj_from_stream ==
                yaml_string_stream_obj_from_string)
        assert obj == obj_from_stream
        assert obj == obj_from_string
        assert obj == yaml_string_obj_from_stream
        assert obj == yaml_string_obj_from_string
        assert obj == obj_from_stream == obj_from_string == yaml_string_obj_from_stream == yaml_string_obj_from_string
        return {'obj': obj,
                'yaml_string': yaml_string,
                'yaml_string_from_stream': yaml_string_from_stream,
                'obj_from_stream': obj_from_stream,
                'obj_from_string': obj_from_string,
                'yaml_string_obj_from_string': yaml_string_obj_from_string}