def test_apply(self):
ctx = Context(name="root")
a = ctx.select("/a")
b = a.select("/b")
def increment(x):
return x + 1
# the value only exists inside the context of the function
# application
applied_ctx = b.apply(increment, a.value)
applied_ctx.set_value(applied_ctx.value)
result = run_policy(ctx.finalize(), {"a": 5})
self.assertEqual(result['b'], 6)
# and just for calisthenics, do it in a different order
ctx = Context(name="root")
a = ctx.select("/a")
applied_ctx = a.apply(increment, a.value)
b = applied_ctx.select("/b")
b.set_value(applied_ctx.value)
result = run_policy(ctx.finalize(), {"a": -3})
self.assertEqual(result['b'], -2)
def test_finalize_two_ctx_values(self):
ctx = Context(name="root")
a = ctx.select("/a")
b = a.select("/b")
c = b.select("/c")
def func(b, a):
return set_value(a + b)
c.append(func, a.value, b.value)
incomplete = c.finalize()
self.assertIsInstance(incomplete, Incomplete)
self.assertIn(a.value, incomplete.missing)
self.assertIn(b.value, incomplete.missing)
completed = incomplete.complete({a.value: 5, b.value: 2})
self.assertIsInstance(completed, PolicyRule)
result = run_policy(completed)
self.assertEqual(result['c'], 7)
# now instead of starting with `c` and supplying 2 values,
# let's start with `b` and only have to supply one value.
incomplete = b.finalize()
self.assertIsInstance(incomplete, Incomplete)
self.assertIn(a.value, incomplete.missing)
self.assertNotIn(b.value, incomplete.missing)
completed = incomplete.complete({a.value: 5})
self.assertIsInstance(completed, PolicyRule)
result = run_policy(completed, {"b": 2})
self.assertEqual(result['c'], 7)
def test_incomplete_hookup(self):
ctx = Context(name="root")
a = ctx.select("/a")
b = a.select("/b")
b.set_value(a.value)
complete = a.finalize()
self.assertIsInstance(complete, PolicyRule)
result = run_policy(complete, {"a": 5})
self.assertEqual(result['b'], 5)
complete = ctx.finalize()
self.assertIsInstance(complete, PolicyRule)
result = run_policy(complete, {"a": 5})
self.assertEqual(result['b'], 5)
def test_subclass_helpers(self):
class ResourceContext(Context):
@property
def resource(self):
return self.scope_subctx("/resource", "resource")
def require_resource(self):
require_ctx = ctx.resource.require()
error_ctx = require_ctx.error_ctx()
error_ctx.select("message").set_value(
"Resource is required"
)
error_ctx.select("code").set_value("MISSING_REQUIRED_RESOURCE")
return require_ctx
ctx = ResourceContext()
ctx.require_resource()
result = run_policy(ctx.finalize(), {})
error = result["errors"][0]
self.assertEqual(error["scope"], "/resource")
self.assertEqual(error["value"], None)
self.assertEqual(len(error["context"]), 2)
expected_context_names = ["resource", "require"]
actual_context_names = [frame.name for frame in error["context"]]
self.assertEqual(expected_context_names, actual_context_names)
policy_asts = [frame.policy_ast for frame in error["context"]]
for ast in policy_asts:
self.assertIsInstance(ast, asts.Node)
def test_each(self):
ctx = Context(name="root")
ref_obj = {
"a": 1,
"c": 3,
"d": 4,
}
eachctx = ctx.select("/dict").each(ref=ref_obj)
ref_value = eachctx.value
eachctx.require(ref_value)
result = run_policy(ctx.finalize(), {
"dict": {"a": 0, "b": 0, "c": 0, "d": 0}
})
self.assertNotIn("data", result)
self.assertIn("errors", result)
errors = result["errors"]
self.assertEqual(len(errors), 1)
error = errors[0]
self.assertEqual(error["scope"], "/dict/b")
self.assertEqual(error["message"], "Value is required.")
def test_finalize_own_ctx_value(self):
ctx = Context(name="root")
a = ctx.select("/a")
b = a.select("/b")
b.set_value(b.value)
completed = b.finalize()
self.assertIsInstance(completed, PolicyRule)
result = run_policy(completed, {"b": 5})
self.assertEqual(result['b'], 5)
completed = ctx.finalize()
self.assertIsInstance(completed, PolicyRule)
result = run_policy(completed, {"b": 5})
self.assertEqual(result['b'], 5)
def test_append_policy(self):
ctx = Context()
policy = regarding('/foo', set_value(5))
ctx.append(policy)
policy = ctx.finalize()
result = run_policy(policy)
self.assertEqual(result['foo'], 5)
def test_subctx_policy(self):
ctx = Context()
subctx = ctx.subctx(
lambda policy_rules: regarding('/foo', *policy_rules)
)
subctx.append(
set_value(5)
)
result = run_policy(ctx.finalize())
self.assertEqual(result['foo'], 5)
def test_append_mixed(self):
ctx = Context(name="root")
a = ctx.select("/a")
b = a.select("/b")
def with_values(a, b):
return set_value(a + b)
b.append(with_values, a.value, unit(2))
result = run_policy(ctx.finalize(), {"a": 5})
self.assertEqual(result['b'], 7)
def test_finalize(self):
ctx = Context(name="root")
a = ctx.select("/a")
b = a.select("/b")
b.set_value(a.value)
incomplete = b.finalize()
self.assertIsInstance(incomplete, Incomplete)
self.assertIn(a.value, incomplete.missing)
completed = incomplete.complete({a.value: 5})
self.assertIsInstance(completed, PolicyRule)
result = run_policy(completed)
self.assertEqual(result['b'], 5)
def test_append_function(self):
ctx = Context()
value = unit(5)
def with_value(value):
return regarding(
'/foo',
set_value(value)
)
ctx.append(with_value, value)
policy = ctx.finalize()
result = run_policy(policy)
self.assertEqual(result['foo'], 5)
def test_whitelist_values(self):
ctx = Context()
ctx.select("/client").whitelist_values(
["ios", "android"]
)
obj = {
"client": "windows"
}
result = run_policy(ctx.finalize(), obj)
error = result["errors"][0]
error_context_names = [frame.name for frame in error['context']]
self.assertIn("whitelist_values", error_context_names)
def test_nesting(self):
ctx = Context(name="root")
a = ctx.select("/a")
b = a.select("/b")
def f_a(a):
return regarding("/results/f_a", set_value(a))
def f_b(b):
return regarding("/results/f_b", set_value(b))
b.append(f_a, a.value)
b.append(f_b, b.value)
c = b.select("/c")
def f_ab(a, b):
return regarding("/results/f_ab", set_value(a + b))
def f_ac(a, c):
return regarding("/results/f_ac", set_value(a + c))
c.append(f_ab, a.value, b.value)
c.append(f_ac, a.value, c.value)
result = run_policy(ctx.finalize(), {
"a": 1,
"b": 2,
"c": 4,
})
a = result['a']
b = result['b']
c = result['c']
f_a = result['results']['f_a']
f_b = result['results']['f_b']
f_ab = result['results']['f_ab']
f_ac = result['results']['f_ac']
self.assertEqual(f_a, a)
self.assertEqual(f_b, b)
self.assertEqual(f_ab, a + b)
self.assertEqual(f_ac, a + c)
def test_subctx_noop_policy(self):
ctx = Context()
foo_ctx_value = ctx.subctx(
lambda policy_rules: regarding('/foo', *policy_rules)
)
def with_foo(foo_value):
return regarding('/bar', set_value(foo_value))
ctx.append(with_foo, foo_ctx_value)
# foo is only used as a value - never being applied policy
# rules itself.
# ctx therefore should only have 1 policy, the `with_foo`
# function above that just sets {foo: *, bar: foo}
items, error_handler = ctx.get_finalized_items()
self.assertEqual(len(items), 1)
result = run_policy(ctx.finalize(), {"foo": "zebra"})
self.assertEqual(result['bar'], "zebra")
def test_apply_dangerous_alchemy(self):
# nice job! and you even finished in time to go foraging for
# more ingredients!
inventory = [
"aqua fortis",
"glauber's salt",
"lunar caustic",
"mosaic gold",
"plumbago",
"salt",
"tin salt",
"butter of tin",
"stibnite",
"naples yellow",
# nice find
"anti-plumbago"
]
# but unfortunately, it's the next day, and the same thing
# has happened to you! except this time it was for your
# other life's goal: discover the ~elixir of discord~!
#
# well, since it was so easy...
whatever_concoction = set(['some ingredients'])
discoveries_today = set([])
should_be_fine = 'overconfidence' not in discoveries_today
assert should_be_fine
# doing alchemy la la la
alchemy_ctx = Context()
# grabbin' things off shelves
selected_first_ctx = alchemy_ctx.select("/inventory").each()
first_substance = selected_first_ctx.value
selected_second_ctx = selected_first_ctx.select("/inventory").each()
second_substance = selected_second_ctx.value
# got our ingredients
got_ingredients_ctx = selected_second_ctx
workstation_ctx = got_ingredients_ctx.select("/workstation")
# mixin' - don't stop to think
def mix(first, second):
mixture = set([first, second])
if mixture == whatever_concoction:
return 'missing elixir'
if mixture == set(['plumbago', 'anti-plumbago']):
return 'concentrated danger'
return 'more brown goo'
mixed_ctx = workstation_ctx.apply(
mix,
first_substance, second_substance
)
resulting_mixture = mixed_ctx.value
mixed_ctx.select("/discoveries").append_value(resulting_mixture)
# wait wait wait!!
def danger(mixture):
if mixture == 'concentrated danger':
return True
return False
# we can't have that.
danger_ctx = mixed_ctx.check(
danger,
resulting_mixture
)
danger_ctx.forbid()
# moral:
#
# a strong understanding of policies and processes facilitates a
# hazard-free lab environment.
result = run_policy(
alchemy_ctx.finalize(),
{"inventory": inventory, "discoveries": discoveries_today}
)
self.assertIn("errors", result)
self.assertTrue(len(result['errors']))
def test_apply_alchemy(self):
# for our test today, we will be doing some basic alchemy
inventory = [
"aqua fortis",
"glauber's salt",
"lunar caustic",
"mosaic gold",
"plumbago",
"salt",
"tin salt",
"butter of tin",
"stibnite",
"naples yellow",
]
# backstory:
# ~~~~~~~~~~
#
# falling asleep last night, you finally figured out how to complete
# your life's work: discovering the elusive *elixir of life*!
#
# and it's only two ingredients! and you have them on hand!
#
# ...
#
# unfortunately this morning you can't remember which two
# ingredients it was.
#
# you'll know it once you've gotten it, just have to try out
# all possible mixtures. (should be safe enough, right?)
forgotten_elixir_of_life = set(random.sample(inventory, 2))
discoveries_today = set(["frantic worry", "breakfast"])
# ok time to go do some arbitrary alchemy!
#
# game plan:
alchemy_ctx = Context()
# you'll grab one ingredient,
selected_first_ctx = alchemy_ctx.select("/inventory").each()
first_substance = selected_first_ctx.value
# and another,
selected_second_ctx = selected_first_ctx.select("/inventory").each()
second_substance = selected_second_ctx.value
# take them to your advanced scientific mixing equipment,
workstation_ctx = selected_second_ctx.select("/workstation")
# (btw this is your advanced scientific procedure that you are
# 100% certain will tell you what some mixture is)
def mix(first, second):
"""takes two ingredients and returns the resulting substance"""
if set([first, second]) == forgotten_elixir_of_life:
return "elixir of life"
return "some kind of brown goo"
# then you'll mix your ingredients...
mixed_ctx = workstation_ctx.apply(
mix,
first_substance, second_substance
)
resulting_mixture = mixed_ctx.value
# ... and! in today's modern age, scientists now know to record their
# results!
mixed_ctx.select("/discoveries").append_value(resulting_mixture)
# got it? good!
result = run_policy(
alchemy_ctx.finalize(),
{"inventory": inventory, "discoveries": discoveries_today}
)
# in a flurry of excitement, i bet you didn't even stop to
# look at your discoveries as you made them!
#
# well, let's see...
self.assertIn("elixir of life", result["discoveries"])
