def test_expression_valid_single_value() -> None:
code_string = 1
expr = Expression(code_string)
assert expr.code_string == str(code_string)
assert expr.evaluate(EvaluationContext()) == 1
code_string = False
expr = Expression(code_string)
assert expr.code_string == str(code_string)
assert expr.evaluate(EvaluationContext()) is False
code_string = '"Hello World"'
expr = Expression(code_string)
assert expr.code_string == code_string
assert expr.evaluate(EvaluationContext()) == "Hello World"
code_string = '[1, 2, 3]'
expr = Expression(code_string)
assert expr.code_string == code_string
assert expr.evaluate(EvaluationContext()) == [1, 2, 3]
code_string = '{"a":1, "b":2}'
expr = Expression(code_string)
assert expr.code_string == code_string
assert expr.evaluate(EvaluationContext()) == {"a": 1, "b": 2}
class StreamingTransformerSchema(TransformerSchema):
"""
Represents the schema for processing streaming data. Handles the streaming specific attributes of the schema
"""
ATTRIBUTE_IDENTITY = 'Identity'
ATTRIBUTE_TIME = 'Time'
def __init__(self, fully_qualified_name: str,
schema_loader: SchemaLoader) -> None:
super().__init__(fully_qualified_name, schema_loader)
self.identity = Expression(
self._spec[self.ATTRIBUTE_IDENTITY]
) if self.ATTRIBUTE_IDENTITY in self._spec else None
self.time = Expression(self._spec[self.ATTRIBUTE_TIME]
) if self.ATTRIBUTE_TIME in self._spec else None
def validate_schema_spec(self) -> None:
super().validate_schema_spec()
self.validate_required_attributes(self.ATTRIBUTE_IDENTITY,
self.ATTRIBUTE_TIME,
self.ATTRIBUTE_STORES)
def get_identity(self, record: Record) -> str:
"""
Evaluates and returns the identity as specified in the schema.
:param record: Record which is used to determine the identity.
:return: The evaluated identity
:raises: IdentityError if identity cannot be determined.
"""
context = self.schema_context.context
context.add_record(record)
identity = self.identity.evaluate(context)
if not identity:
raise IdentityError(
'Could not determine identity using {}. Record is {}'.format(
self.identity.code_string, record))
context.remove_record()
return identity
def get_time(self, record: Record) -> datetime:
context = self.schema_context.context
context.add_record(record)
time = self.time.evaluate(context)
if not time or not isinstance(time, datetime):
raise TimeError(
'Could not determine time using {}. Record is {}'.format(
self.time.code_string, record))
context.remove_record()
return time
def test_expression_globals_locals() -> None:
code_string = 'a + b + 1'
expr = Expression(code_string)
with pytest.raises(NameError, match='name \'a\' is not defined'):
expr.evaluate(EvaluationContext())
assert expr.evaluate(EvaluationContext(Context({'a': 2, 'b': 3}))) == 6
assert expr.evaluate(
EvaluationContext(local_context=Context({
'a': 2,
'b': 3
}))) == 6
assert expr.evaluate(
EvaluationContext(Context({'a': 2}), Context({'b': 3}))) == 6
def test_expression_user_function() -> None:
code_string = '2 if test_function() else 3'
def test_function():
return 3 > 4
expr = Expression(code_string)
assert expr.evaluate(
EvaluationContext(Context({'test_function': test_function}))) == 3
def test_expression_conditional() -> None:
code_string = '1 if 2 > 1 else 3'
expr = Expression(code_string)
assert expr.evaluate(EvaluationContext()) == 1
