#854 [BUG] Flytekit entity patch command interferes with mock.patch Issue created by wild-endeavor Describe the bug This short test file will reproduce the issue. If you copy paste this into a test file, each of the two tests will succeed on its own. However if you run it together as a file in a pytest command, it will break.

import pytest
from mock import patch as _system_patch

from flytekit.core.task import task
from flytekit.core.testing import patch as flyte_patch
from flytekit.core.workflow import ImperativeWorkflow, workflow


@task
def t1(a: str) -> str:
    return a + " world"


wb = ImperativeWorkflow(name="my.workflow")
wb.add_workflow_input("in1", str)
node = wb.add_entity(t1, a=wb.inputs["in1"])
wb.add_workflow_output("from_n0t1", node.outputs["o0"])


@_system_patch("flytekit.core.workflow.ImperativeWorkflow.execute")
def test_return_none_errors(mock_execute):
    mock_execute.return_value = None
    with pytest.raises(Exception):
        wb(in1="hello")


@flyte_patch(wb)
def test_imperative_patching(mock_wb):
    mock_wb.return_value = "hi"

    @workflow
    def my_functional_wf(a: str) -> str:
        x = wb(in1=a)
        return x

    assert my_functional_wf(a="hello") == "hi"

It is unclear what is happening. Somehow, the

flyte_patch

patching logic is interfering with the normal

mock.patch

. The mere presence of the second test, basically makes it seem like the

mock.patch

isn't there on the first test. Basically

ImperativeWorkflow.execute

is not patched and returns what it normally would return, and hence the exception isn't raised. If you copy paste the

wb

workflow and use a new variable for it for the second test, then things pass. This will take some digging into the mock library to understand how they're interfering with each other. flyteorg/flyte