def evaluate(cls, expression, data_context):
LOG.debug(
"Evaluating Jinja expression [expression='%s', context=%s]"
% (expression, data_context)
)
opts = {'undefined_to_none': False}
ctx = expression_utils.get_jinja_context(data_context)
try:
result = cls._env.compile_expression(expression, **opts)(**ctx)
# For StrictUndefined values, UndefinedError only gets raised when
# the value is accessed, not when it gets created. The simplest way
# to access it is to try and cast it to string.
str(result)
except Exception as e:
raise exc.JinjaEvaluationException(
"Can not evaluate Jinja expression [expression=%s, error=%s"
", data=%s]" % (expression, str(e), data_context)
)
LOG.debug("Jinja expression result: %s" % result)
return result
def evaluate(cls, expression, data_context):
opts = {'undefined_to_none': False}
ctx = expression_utils.get_jinja_context(data_context)
try:
result = cls._env.compile_expression(expression, **opts)(**ctx)
# For StrictUndefined values, UndefinedError only gets raised when
# the value is accessed, not when it gets created. The simplest way
# to access it is to try and cast it to string.
str(result)
except Exception as e:
# NOTE(rakhmerov): if we hit a database error then we need to
# re-raise the initial exception so that upper layers had a
# chance to handle it properly (e.g. in case of DB deadlock
# the operations needs to retry. Essentially, such situation
# indicates a problem with DB rather than with the expression
# syntax or values.
if isinstance(e, db_exc.DBError):
LOG.error(
"Failed to evaluate Jinja expression due to a database"
" error, re-raising initial exception [expression=%s,"
" error=%s, data=%s]", expression, str(e), data_context)
raise e
raise exc.JinjaEvaluationException(
"Can not evaluate Jinja expression [expression=%s, error=%s"
", data=%s]" % (expression, str(e), data_context))
return result
def evaluate(cls, expression, data_context):
ctx = expression_utils.get_jinja_context(data_context)
result = cls._env.compile_expression(expression, **JINJA_OPTS)(**ctx)
# For StrictUndefined values, UndefinedError only gets raised when
# the value is accessed, not when it gets created. The simplest way
# to access it is to try and cast it to string.
str(result)
return result
def evaluate(cls, expression, data_context):
ctx = expression_utils.get_jinja_context(data_context)
result = cls._env.compile_expression(
expression,
**JINJA_OPTS
)(**ctx)
# For StrictUndefined values, UndefinedError only gets raised when
# the value is accessed, not when it gets created. The simplest way
# to access it is to try and cast it to string.
str(result)
return result
def evaluate(cls, expression, data_context):
LOG.debug("Evaluating Jinja expression [expression='%s', context=%s]" %
(expression, data_context))
patterns = cls.find_expression_pattern.findall(expression)
if patterns[0][0] == expression:
result = JinjaEvaluator.evaluate(patterns[0][1], data_context)
else:
ctx = expression_utils.get_jinja_context(data_context)
result = cls._env.from_string(expression).render(**ctx)
LOG.debug("Jinja expression result: %s" % result)
return result
def evaluate(cls, expression, data_context):
LOG.debug(
"Start to evaluate Jinja expression. "
"[expression='%s', context=%s]",
expression,
data_context
)
patterns = cls.find_expression_pattern.findall(expression)
try:
if patterns[0][0] == expression:
result = JinjaEvaluator.evaluate(patterns[0][1], data_context)
else:
ctx = expression_utils.get_jinja_context(data_context)
result = cls._env.from_string(expression).render(**ctx)
except Exception as e:
# NOTE(rakhmerov): if we hit a database error then we need to
# re-raise the initial exception so that upper layers had a
# chance to handle it properly (e.g. in case of DB deadlock
# the operations needs to retry. Essentially, such situation
# indicates a problem with DB rather than with the expression
# syntax or values.
if isinstance(e, db_exc.DBError):
LOG.error(
"Failed to evaluate Jinja expression due to a database"
" error, re-raising initial exception [expression=%s,"
" error=%s, data=%s]",
expression,
str(e),
data_context
)
raise e
raise exc.JinjaEvaluationException(
"Can not evaluate Jinja expression [expression=%s, error=%s"
", data=%s]" % (expression, str(e), data_context)
)
LOG.debug(
"Finished evaluation. [expression='%s', result: %s]",
expression,
result
)
return result
def evaluate(cls, expression, data_context):
LOG.debug(
"Start to evaluate Jinja expression. "
"[expression='%s', context=%s]", expression, data_context)
patterns = cls.find_expression_pattern.findall(expression)
if patterns[0][0] == expression:
result = JinjaEvaluator.evaluate(patterns[0][1], data_context)
else:
ctx = expression_utils.get_jinja_context(data_context)
result = cls._env.from_string(expression).render(**ctx)
LOG.debug("Finished evaluation. [expression='%s', result: %s]",
expression, result)
return result
def evaluate(cls, expression, data_context):
LOG.debug(
"Evaluating Jinja expression [expression='%s', context=%s]"
% (expression, data_context)
)
patterns = cls.find_expression_pattern.findall(expression)
if patterns[0][0] == expression:
result = JinjaEvaluator.evaluate(patterns[0][1], data_context)
else:
ctx = expression_utils.get_jinja_context(data_context)
result = cls._env.from_string(expression).render(**ctx)
LOG.debug("Jinja expression result: %s" % result)
return result
def evaluate(cls, expression, data_context):
opts = {'undefined_to_none': False}
ctx = expression_utils.get_jinja_context(data_context)
try:
result = cls._env.compile_expression(expression, **opts)(**ctx)
# For StrictUndefined values, UndefinedError only gets raised when
# the value is accessed, not when it gets created. The simplest way
# to access it is to try and cast it to string.
str(result)
except Exception as e:
raise exc.JinjaEvaluationException(
"Can not evaluate Jinja expression [expression=%s, error=%s"
", data=%s]" % (expression, str(e), data_context))
return result
def evaluate(cls, expression, data_context):
LOG.debug("Evaluating Jinja expression [expression='%s', context=%s]" %
(expression, data_context))
opts = {'undefined_to_none': False}
ctx = expression_utils.get_jinja_context(data_context)
try:
result = cls._env.compile_expression(expression, **opts)(**ctx)
# For StrictUndefined values, UndefinedError only gets raised when
# the value is accessed, not when it gets created. The simplest way
# to access it is to try and cast it to string.
str(result)
except jinja2.exceptions.UndefinedError as e:
raise exc.JinjaEvaluationException("Undefined error '%s'." %
str(e))
LOG.debug("Jinja expression result: %s" % result)
return result
def evaluate(cls, expression, data_context):
LOG.debug(
"Start to evaluate Jinja expression. "
"[expression='%s', context=%s]", expression, data_context)
patterns = cls.find_expression_pattern.findall(expression)
try:
if patterns[0][0] == expression:
result = JinjaEvaluator.evaluate(patterns[0][1], data_context)
else:
ctx = expression_utils.get_jinja_context(data_context)
result = cls._env.from_string(expression).render(**ctx)
except Exception as e:
# NOTE(rakhmerov): if we hit a database error then we need to
# re-raise the initial exception so that upper layers had a
# chance to handle it properly (e.g. in case of DB deadlock
# the operations needs to retry. Essentially, such situation
# indicates a problem with DB rather than with the expression
# syntax or values.
if isinstance(e, db_exc.DBError):
LOG.error(
"Failed to evaluate Jinja expression due to a database"
" error, re-raising initial exception [expression=%s,"
" error=%s, data=%s]", expression, str(e), data_context)
raise e
raise exc.JinjaEvaluationException(
"Can not evaluate Jinja expression [expression=%s, error=%s"
", data=%s]" % (expression, str(e), data_context))
LOG.debug("Finished evaluation. [expression='%s', result: %s]",
expression, result)
return result
class ErrorHandlingEngineTest(base.EngineTestCase):
def test_invalid_workflow_input(self):
# Check that in case of invalid input workflow objects aren't even
# created.
wf_text = """
version: '2.0'
wf:
input:
- param1
- param2
tasks:
task1:
action: std.noop
"""
wf_service.create_workflows(wf_text)
self.assertRaises(
exc.InputException,
self.engine.start_workflow,
'wf',
'',
{'wrong_param': 'some_value'}
)
self.assertEqual(0, len(db_api.get_workflow_executions()))
self.assertEqual(0, len(db_api.get_task_executions()))
self.assertEqual(0, len(db_api.get_action_executions()))
def test_first_task_error(self):
# Check that in case of an error in first task workflow objects are
# still persisted properly.
wf_text = """
version: '2.0'
wf:
tasks:
task1:
action: std.fail
on-success: task2
task2:
action: std.noop
"""
wf_service.create_workflows(wf_text)
wf_ex = self.engine.start_workflow('wf')
self.assertEqual(states.RUNNING, wf_ex.state)
self.assertIsNotNone(db_api.get_workflow_execution(wf_ex.id))
self.await_workflow_error(wf_ex.id)
with db_api.transaction():
wf_ex = db_api.get_workflow_execution(wf_ex.id)
task_execs = wf_ex.task_executions
self.assertEqual(1, len(task_execs))
self._assert_single_item(task_execs, name='task1', state=states.ERROR)
def test_action_error(self):
# Check that state of all workflow objects (workflow executions,
# task executions, action executions) is properly persisted in case
# of action error.
wf_text = """
version: '2.0'
wf:
tasks:
task1:
action: std.fail
"""
wf_service.create_workflows(wf_text)
wf_ex = self.engine.start_workflow('wf')
self.await_workflow_error(wf_ex.id)
with db_api.transaction():
wf_ex = db_api.get_workflow_execution(wf_ex.id)
task_execs = wf_ex.task_executions
self.assertEqual(1, len(task_execs))
self._assert_single_item(task_execs, name='task1', state=states.ERROR)
def test_task_error(self):
# Check that state of all workflow objects (workflow executions,
# task executions, action executions) is properly persisted in case
# of an error at task level.
wf_text = """
version: '2.0'
wf:
tasks:
task1:
action: std.noop
publish:
my_var: <% invalid_yaql_function() %>
"""
wf_service.create_workflows(wf_text)
wf_ex = self.engine.start_workflow('wf')
self.await_workflow_error(wf_ex.id)
with db_api.transaction():
wf_ex = db_api.get_workflow_execution(wf_ex.id)
# Now we need to make sure that task is in ERROR state but action
# is in SUCCESS because error occurred in 'publish' clause which
# must not affect action state.
task_execs = wf_ex.task_executions
self.assertEqual(1, len(task_execs))
task_ex = self._assert_single_item(
task_execs,
name='task1',
state=states.ERROR
)
action_execs = task_ex.executions
self.assertEqual(1, len(action_execs))
self._assert_single_item(
action_execs,
name='std.noop',
state=states.SUCCESS
)
def test_task_error_with_on_handlers(self):
# Check that state of all workflow objects (workflow executions,
# task executions, action executions) is properly persisted in case
# of an error at task level and this task has on-XXX handlers.
wf_text = """
version: '2.0'
wf:
tasks:
task1:
action: std.noop
publish:
my_var: <% invalid_yaql_function() %>
on-success:
- task2
on-error:
- task3
task2:
description: This task must never run.
action: std.noop
task3:
action: std.noop
"""
wf_service.create_workflows(wf_text)
wf_ex = self.engine.start_workflow('wf')
self.await_workflow_error(wf_ex.id)
with db_api.transaction():
wf_ex = db_api.get_workflow_execution(wf_ex.id)
# Now we need to make sure that task is in ERROR state but action
# is in SUCCESS because error occurred in 'publish' clause which
# must not affect action state.
task_execs = wf_ex.task_executions
# NOTE: task3 must not run because on-error handler triggers
# only on error outcome of an action (or workflow) associated
# with a task.
self.assertEqual(1, len(task_execs))
task_ex = self._assert_single_item(
task_execs,
name='task1',
state=states.ERROR
)
action_execs = task_ex.executions
self.assertEqual(1, len(action_execs))
self._assert_single_item(
action_execs,
name='std.noop',
state=states.SUCCESS
)
def test_workflow_error(self):
# Check that state of all workflow objects (workflow executions,
# task executions, action executions) is properly persisted in case
# of an error at task level.
wf_text = """
version: '2.0'
wf:
output:
my_output: <% $.invalid_yaql_variable %>
tasks:
task1:
action: std.noop
"""
wf_service.create_workflows(wf_text)
wf_ex = self.engine.start_workflow('wf')
self.await_workflow_error(wf_ex.id)
with db_api.transaction():
wf_ex = db_api.get_workflow_execution(wf_ex.id)
# Now we need to make sure that task and action are in SUCCESS
# state because mistake at workflow level (output evaluation)
# must not affect them.
task_execs = wf_ex.task_executions
self.assertEqual(1, len(task_execs))
task_ex = self._assert_single_item(
task_execs,
name='task1',
state=states.SUCCESS
)
action_execs = task_ex.executions
self.assertEqual(1, len(action_execs))
self._assert_single_item(
action_execs,
name='std.noop',
state=states.SUCCESS
)
def test_action_error_with_wait_before_policy(self):
# Check that state of all workflow objects (workflow executions,
# task executions, action executions) is properly persisted in case
# of action error and task has 'wait-before' policy. It is an
# implicit test for task continuation because 'wait-before' inserts
# a delay between preparing task execution object and scheduling
# actions. If an error happens during scheduling actions (e.g.
# invalid YAQL in action parameters) then we also need to handle
# this properly, meaning that task and workflow state should go
# into ERROR state.
wf_text = """
version: '2.0'
wf:
tasks:
task1:
action: std.echo output=<% invalid_yaql_function() %>
wait-before: 1
"""
wf_service.create_workflows(wf_text)
wf_ex = self.engine.start_workflow('wf')
self.await_workflow_error(wf_ex.id)
with db_api.transaction():
wf_ex = db_api.get_workflow_execution(wf_ex.id)
task_execs = wf_ex.task_executions
self.assertEqual(1, len(task_execs))
task_ex = self._assert_single_item(
task_execs,
name='task1',
state=states.ERROR
)
action_execs = task_ex.executions
self.assertEqual(0, len(action_execs))
def test_action_error_with_wait_after_policy(self):
# Check that state of all workflow objects (workflow executions,
# task executions, action executions) is properly persisted in case
# of action error and task has 'wait-after' policy. It is an
# implicit test for task completion because 'wait-after' inserts
# a delay between actual task completion and logic that calculates
# next workflow commands. If an error happens while calculating
# next commands (e.g. invalid YAQL in on-XXX clauses) then we also
# need to handle this properly, meaning that task and workflow state
# should go into ERROR state.
wf_text = """
version: '2.0'
wf:
tasks:
task1:
action: std.noop
wait-after: 1
on-success:
- task2: <% invalid_yaql_function() %>
task2:
action: std.noop
"""
wf_service.create_workflows(wf_text)
wf_ex = self.engine.start_workflow('wf')
self.await_workflow_error(wf_ex.id)
with db_api.transaction():
wf_ex = db_api.get_workflow_execution(wf_ex.id)
task_execs = wf_ex.task_executions
self.assertEqual(1, len(task_execs))
task_ex = self._assert_single_item(
task_execs,
name='task1',
state=states.ERROR
)
action_execs = task_ex.executions
self.assertEqual(1, len(action_execs))
self._assert_single_item(
action_execs,
name='std.noop',
state=states.SUCCESS
)
def test_error_message_format_key_error(self):
wf_text = """
version: '2.0'
wf:
tasks:
task1:
action: std.noop
on-success:
- succeed: <% $.invalid_yaql %>
"""
wf_service.create_workflows(wf_text)
wf_ex = self.engine.start_workflow('wf')
self.await_workflow_error(wf_ex.id)
with db_api.transaction():
wf_ex = db_api.get_workflow_execution(wf_ex.id)
task_ex = wf_ex.task_executions[0]
state_info = task_ex.state_info
self.assertIsNotNone(state_info)
self.assertLess(state_info.find('error'), state_info.find('data'))
def test_error_message_format_unknown_function(self):
wf_text = """
version: '2.0'
wf:
tasks:
task1:
action: std.noop
publish:
my_var: <% invalid_yaql_function() %>
"""
wf_service.create_workflows(wf_text)
wf_ex = self.engine.start_workflow('wf')
self.await_workflow_error(wf_ex.id)
with db_api.transaction():
wf_ex = db_api.get_workflow_execution(wf_ex.id)
task_ex = wf_ex.task_executions[0]
state_info = task_ex.state_info
self.assertIsNotNone(state_info)
self.assertGreater(state_info.find('error='), 0)
self.assertLess(state_info.find('error='), state_info.find('data='))
def test_error_message_format_invalid_on_task_run(self):
wf_text = """
version: '2.0'
wf:
tasks:
task1:
action: std.echo output={{ _.invalid_var }}
"""
wf_service.create_workflows(wf_text)
wf_ex = self.engine.start_workflow('wf')
self.await_workflow_error(wf_ex.id)
with db_api.transaction():
wf_ex = db_api.get_workflow_execution(wf_ex.id)
task_ex = wf_ex.task_executions[0]
state_info = task_ex.state_info
self.assertIsNotNone(state_info)
self.assertGreater(state_info.find('error='), 0)
self.assertLess(state_info.find('error='), state_info.find('wf='))
def test_error_message_format_on_task_continue(self):
wf_text = """
version: '2.0'
wf:
tasks:
task1:
action: std.echo output={{ _.invalid_var }}
wait-before: 1
"""
wf_service.create_workflows(wf_text)
wf_ex = self.engine.start_workflow('wf')
self.await_workflow_error(wf_ex.id)
with db_api.transaction():
wf_ex = db_api.get_workflow_execution(wf_ex.id)
task_ex = wf_ex.task_executions[0]
state_info = task_ex.state_info
self.assertIsNotNone(state_info)
self.assertGreater(state_info.find('error='), 0)
self.assertLess(state_info.find('error='), state_info.find('wf='))
def test_error_message_format_on_action_complete(self):
wf_text = """
version: '2.0'
wf:
tasks:
task1:
action: std.noop
publish:
my_var: <% invalid_yaql_function() %>
"""
wf_service.create_workflows(wf_text)
wf_ex = self.engine.start_workflow('wf')
self.await_workflow_error(wf_ex.id)
with db_api.transaction():
wf_ex = db_api.get_workflow_execution(wf_ex.id)
task_ex = wf_ex.task_executions[0]
state_info = task_ex.state_info
print(state_info)
self.assertIsNotNone(state_info)
self.assertGreater(state_info.find('error='), 0)
self.assertLess(state_info.find('error='), state_info.find('wf='))
def test_error_message_format_complete_task(self):
wf_text = """
version: '2.0'
wf:
tasks:
task1:
action: std.noop
wait-after: 1
on-success:
- task2: <% invalid_yaql_function() %>
task2:
action: std.noop
"""
wf_service.create_workflows(wf_text)
wf_ex = self.engine.start_workflow('wf')
self.await_workflow_error(wf_ex.id)
with db_api.transaction():
wf_ex = db_api.get_workflow_execution(wf_ex.id)
task_ex = wf_ex.task_executions[0]
state_info = task_ex.state_info
self.assertIsNotNone(state_info)
self.assertGreater(state_info.find('error='), 0)
self.assertLess(state_info.find('error='), state_info.find('wf='))
def test_error_message_format_on_adhoc_action_error(self):
wb_text = """
version: '2.0'
name: wb
actions:
my_action:
input:
- output
output: <% invalid_yaql_function() %>
base: std.echo
base-input:
output: <% $.output %>
workflows:
wf:
tasks:
task1:
action: my_action output="test"
"""
wb_service.create_workbook_v2(wb_text)
wf_ex = self.engine.start_workflow('wb.wf')
self.await_workflow_error(wf_ex.id)
with db_api.transaction():
wf_ex = db_api.get_workflow_execution(wf_ex.id)
task_ex = wf_ex.task_executions[0]
state_info = task_ex.state_info
self.assertIsNotNone(state_info)
self.assertGreater(state_info.find('error='), 0)
self.assertLess(state_info.find('error='), state_info.find('action='))
def test_publish_bad_yaql(self):
wf_text = """---
version: '2.0'
wf:
type: direct
input:
- my_dict:
- id: 1
value: 11
tasks:
task1:
action: std.noop
publish:
problem_var: <% $.my_dict.where($.value = 13).id.first() %>
"""
wf_service.create_workflows(wf_text)
wf_ex = self.engine.start_workflow('wf')
self.await_workflow_error(wf_ex.id)
with db_api.transaction():
wf_ex = db_api.get_workflow_execution(wf_ex.id)
task_ex = wf_ex.task_executions[0]
action_ex = task_ex.action_executions[0]
self.assertEqual(states.SUCCESS, action_ex.state)
self.assertEqual(states.ERROR, task_ex.state)
self.assertIsNotNone(task_ex.state_info)
self.assertEqual(states.ERROR, wf_ex.state)
def test_publish_bad_jinja(self):
wf_text = """---
version: '2.0'
wf:
type: direct
input:
- my_dict:
- id: 1
value: 11
tasks:
task1:
action: std.noop
publish:
problem_var: '{{ (_.my_dict|some_invalid_filter).id }}'
"""
wf_service.create_workflows(wf_text)
wf_ex = self.engine.start_workflow('wf')
self.await_workflow_error(wf_ex.id)
with db_api.transaction():
wf_ex = db_api.get_workflow_execution(wf_ex.id)
task_ex = wf_ex.task_executions[0]
action_ex = task_ex.action_executions[0]
self.assertEqual(states.SUCCESS, action_ex.state)
self.assertEqual(states.ERROR, task_ex.state)
self.assertIsNotNone(task_ex.state_info)
self.assertEqual(states.ERROR, wf_ex.state)
def test_invalid_task_input(self):
wf_text = """---
version: '2.0'
wf:
tasks:
task1:
action: std.noop
on-success: task2
task2:
action: std.echo output=<% $.non_existing_function_AAA() %>
"""
wf_service.create_workflows(wf_text)
wf_ex = self.engine.start_workflow('wf')
self.await_workflow_error(wf_ex.id)
with db_api.transaction():
wf_ex = db_api.get_workflow_execution(wf_ex.id)
tasks = wf_ex.task_executions
self.assertEqual(2, len(tasks))
self._assert_single_item(tasks, name='task1', state=states.SUCCESS)
t2 = self._assert_single_item(tasks, name='task2', state=states.ERROR)
self.assertIsNotNone(t2.state_info)
self.assertIn('Can not evaluate YAQL expression', t2.state_info)
self.assertIsNotNone(wf_ex.state_info)
self.assertIn('Can not evaluate YAQL expression', wf_ex.state_info)
def test_invalid_action_result(self):
self.register_action_class(
'test.invalid_unicode_action',
InvalidUnicodeAction
)
wf_text = """---
version: '2.0'
wf:
tasks:
task1:
action: test.invalid_unicode_action
on-success: task2
task2:
action: std.noop
"""
wf_service.create_workflows(wf_text)
wf_ex = self.engine.start_workflow('wf')
self.await_workflow_error(wf_ex.id)
with db_api.transaction():
wf_ex = db_api.get_workflow_execution(wf_ex.id)
self.assertEqual(1, len(wf_ex.task_executions))
task_ex = wf_ex.task_executions[0]
self.assertIn("UnicodeDecodeError: utf", wf_ex.state_info)
self.assertIn("UnicodeDecodeError: utf", task_ex.state_info)
@mock.patch(
'mistral.utils.expression_utils.get_yaql_context',
mock.MagicMock(
side_effect=[
db_exc.DBDeadlock(), # Emulating DB deadlock
expression_utils.get_yaql_context({}) # Successful run
]
)
)
def test_db_error_in_yaql_expression(self):
# This test just checks that the workflow completes successfully
# even if a DB deadlock occurs during YAQL expression evaluation.
# The engine in this case should should just retry the transactional
# method.
wf_text = """---
version: '2.0'
wf:
tasks:
task1:
action: std.echo output="Hello"
publish:
my_var: <% 1 + 1 %>
"""
wf_service.create_workflows(wf_text)
wf_ex = self.engine.start_workflow('wf')
self.await_workflow_success(wf_ex.id)
with db_api.transaction():
wf_ex = db_api.get_workflow_execution(wf_ex.id)
self.assertEqual(1, len(wf_ex.task_executions))
task_ex = wf_ex.task_executions[0]
self.assertDictEqual({'my_var': 2}, task_ex.published)
@mock.patch(
'mistral.utils.expression_utils.get_jinja_context',
mock.MagicMock(
side_effect=[
db_exc.DBDeadlock(), # Emulating DB deadlock
expression_utils.get_jinja_context({}) # Successful run
]
)
)
def test_db_error_in_jinja_expression(self):
# This test just checks that the workflow completes successfully
# even if a DB deadlock occurs during Jinja expression evaluation.
# The engine in this case should should just retry the transactional
# method.
wf_text = """---
version: '2.0'
wf:
tasks:
task1:
action: std.echo output="Hello"
publish:
my_var: "{{ 1 + 1 }}"
"""
wf_service.create_workflows(wf_text)
wf_ex = self.engine.start_workflow('wf')
self.await_workflow_success(wf_ex.id)
with db_api.transaction():
wf_ex = db_api.get_workflow_execution(wf_ex.id)
self.assertEqual(1, len(wf_ex.task_executions))
task_ex = wf_ex.task_executions[0]
self.assertDictEqual({'my_var': 2}, task_ex.published)
