def all_enabled(user=None):
"""Return a list of enabled features and experiments for the user.
Provides the user's assigned variant and the experiment ID for experiments.
This does not trigger bucketing events, so it should not be used for
feature flagging purposes on the server. It is meant to let clients
condition features on experiment variants. Those clients should manually
send the appropriate bucketing events.
:param user - (optional) an Account. Defaults to None, for which we
determine logged-out features.
:return dict - a dictionary mapping enabled feature keys to True or to the
experiment/variant information
"""
features = FeatureState.get_all(_world)
# Get enabled features and experiments
active = {}
for feature in features:
experiment = feature.config.get('experiment')
if experiment:
# Get experiment names, ids, and assigned variants, leaving out
# experiments for which this user is excluded
variant = feature.variant(user)
if variant:
active[feature.name] = {
'experiment_id': experiment.get('experiment_id'),
'variant': variant
}
elif feature.is_enabled(user):
active[feature.name] = True
return active
def _get_featurestate(name):
"""Get a FeatureState object for this feature, creating it if necessary.
:param name string - a given feature name
:return FeatureState
"""
if name not in _featurestate_cache:
_featurestate_cache[name] = FeatureState(name, _world)
return _featurestate_cache[name]
def _get_featurestate(name):
"""Get a FeatureState object for this feature, creating it if necessary.
:param name string - a given feature name
:return FeatureState
"""
featurestate = _featurestate_cache.get(name, None)
if featurestate is None:
featurestate = FeatureState(name, _world)
_featurestate_cache[name] = featurestate
return featurestate
def test_choose_variant(self):
"""Test FeatureState's _choose_variant function."""
no_variants = {}
three_variants = {
'remove_vote_counters': 5,
'control_1': 10,
'control_2': 5,
}
three_variants_more = {
'remove_vote_counters': 15.6,
'control_1': 10,
'control_2': 20,
}
counters = collections.defaultdict(collections.Counter)
for bucket in xrange(FeatureState.NUM_BUCKETS):
variant = FeatureState._choose_variant(bucket, no_variants)
if variant:
counters['no_variants'][variant] += 1
# Ensure variant-choosing is deterministic.
self.assertEqual(
variant,
FeatureState._choose_variant(bucket, no_variants))
variant = FeatureState._choose_variant(bucket, three_variants)
if variant:
counters['three_variants'][variant] += 1
# Ensure variant-choosing is deterministic.
self.assertEqual(
variant,
FeatureState._choose_variant(bucket, three_variants))
previous_variant = variant
variant = FeatureState._choose_variant(bucket, three_variants_more)
if variant:
counters['three_variants_more'][variant] += 1
# Ensure variant-choosing is deterministic.
self.assertEqual(
variant,
FeatureState._choose_variant(bucket, three_variants_more))
# If previously we had a variant, we should still have the same one
# now.
if previous_variant:
self.assertEqual(variant, previous_variant)
# Only controls chosen in the no-variant case.
for variant, percentage in FeatureState.DEFAULT_CONTROL_GROUPS.items():
count = counters['no_variants'][variant]
# The variant percentage is expressed as a part of 100, so we need
# to calculate the fraction-of-1 percentage and scale it
# accordingly.
scaled_percentage = float(count) / (FeatureState.NUM_BUCKETS / 100)
self.assertEqual(scaled_percentage, percentage)
for variant, percentage in three_variants.items():
count = counters['three_variants'][variant]
scaled_percentage = float(count) / (FeatureState.NUM_BUCKETS / 100)
self.assertEqual(scaled_percentage, percentage)
for variant, percentage in three_variants_more.items():
count = counters['three_variants_more'][variant]
scaled_percentage = float(count) / (FeatureState.NUM_BUCKETS / 100)
self.assertEqual(scaled_percentage, percentage)
# Test boundary conditions around the maximum percentage allowed for
# variants.
fifty_fifty = {
'control_1': 50,
'control_2': 50,
}
almost_fifty_fifty = {
'control_1': 49,
'control_2': 51,
}
for bucket in xrange(FeatureState.NUM_BUCKETS):
variant = FeatureState._choose_variant(bucket, fifty_fifty)
counters['fifty_fifty'][variant] += 1
variant = FeatureState._choose_variant(bucket, almost_fifty_fifty)
counters['almost_fifty_fifty'][variant] += 1
count = counters['fifty_fifty']['control_1']
scaled_percentage = float(count) / (FeatureState.NUM_BUCKETS / 100)
self.assertEqual(scaled_percentage, 50)
count = counters['fifty_fifty']['control_2']
scaled_percentage = float(count) / (FeatureState.NUM_BUCKETS / 100)
self.assertEqual(scaled_percentage, 50)
count = counters['almost_fifty_fifty']['control_1']
scaled_percentage = float(count) / (FeatureState.NUM_BUCKETS / 100)
self.assertEqual(scaled_percentage, 49)
count = counters['almost_fifty_fifty']['control_2']
scaled_percentage = float(count) / (FeatureState.NUM_BUCKETS / 100)
self.assertEqual(scaled_percentage, 50)
