Hi Dian, However users do want to unit test their UDFs, as supported in https://ci.apache.org/projects/flink/flink-docs-stable/dev/stream/testing.html#testing-user-defined-functions
Even though the examples are for Flink, I believe PyFlink should ideally be no difference. What do you think? Best, Yik San On Tue, Mar 23, 2021 at 2:19 PM Dian Fu <dian0511...@gmail.com> wrote: > Hi Yik San, > > This field isn't expected to be exposed to users and so I'm not convinced > that we should add such an interface/method in Flink. > > Regards, > Dian > > On Tue, Mar 23, 2021 at 2:04 PM Yik San Chan <evan.chanyik...@gmail.com> > wrote: > >> Hi Dian, >> >> The ._func method seems to be internal only. Maybe we can add some >> public-facing method to make it more intuitive for use in unit test? >> What do you think? >> >> Best, >> Yik San >> >> On Tue, Mar 23, 2021 at 2:02 PM Yik San Chan <evan.chanyik...@gmail.com> >> wrote: >> >>> Hi Dian, >>> >>> Thanks! It solves my problem. >>> >>> Best, >>> Yik San >>> >>> On Tue, Mar 23, 2021 at 1:29 PM Dian Fu <dian0511...@gmail.com> wrote: >>> >>>> H Yik San, >>>> >>>> As the udf `add` is decorated with `@udf` decorator, it is no longer a >>>> simple Python function if you reference `add`. If you execute >>>> `print(type(add(1, 1)))`, you will see the output is something like "<class >>>> 'pyflink.table.expression.Expression'>". >>>> >>>> You could try the following code: assert add._func(1, 1) == 3 >>>> >>>> add._func returns the original Python function. >>>> >>>> Regards, >>>> Dian >>>> >>>> On Tue, Mar 23, 2021 at 10:56 AM Yik San Chan < >>>> evan.chanyik...@gmail.com> wrote: >>>> >>>>> (This question is cross-posted on StackOverflow >>>>> https://stackoverflow.com/questions/66756612/failed-to-unit-test-pyflink-udf >>>>> ) >>>>> >>>>> I am using PyFlink and I want to unit test my UDF written in Python. >>>>> >>>>> To test the simple udf below: >>>>> >>>>> ```python >>>>> # tasks/helloworld/udf.py >>>>> from pyflink.table import DataTypes >>>>> from pyflink.table.udf import udf >>>>> >>>>> @udf(input_types=[DataTypes.INT(), DataTypes.INT()], >>>>> result_type=DataTypes.BIGINT()) >>>>> def add(i, j): >>>>> return i + j >>>>> ``` >>>>> >>>>> I create a test file that should fail: >>>>> ```python >>>>> from tasks.helloworld.udf import add >>>>> >>>>> def test_add(): >>>>> assert add(1,1) == 3 >>>>> ``` >>>>> >>>>> Sadly, it passes if I run `pytest`: >>>>> ``` >>>>> > pytest >>>>> =========================================================================================== >>>>> test session starts >>>>> ============================================================================================ >>>>> platform darwin -- Python 3.7.10, pytest-6.2.2, py-1.10.0, >>>>> pluggy-0.13.1 >>>>> rootdir: /Users/chenyisheng/source/yiksanchan/pytest-flink >>>>> collected 1 item >>>>> >>>>> tests/test_helloworld.py . >>>>> >>>>> [100%] >>>>> >>>>> ============================================================================================= >>>>> warnings summary >>>>> ============================================================================================= >>>>> >>>>> ../../../../../usr/local/anaconda3/envs/pyflink-quickstart/lib/python3.7/site-packages/py4j/java_collections.py:13 >>>>> >>>>> ../../../../../usr/local/anaconda3/envs/pyflink-quickstart/lib/python3.7/site-packages/py4j/java_collections.py:13 >>>>> >>>>> ../../../../../usr/local/anaconda3/envs/pyflink-quickstart/lib/python3.7/site-packages/py4j/java_collections.py:13 >>>>> >>>>> ../../../../../usr/local/anaconda3/envs/pyflink-quickstart/lib/python3.7/site-packages/py4j/java_collections.py:13 >>>>> >>>>> ../../../../../usr/local/anaconda3/envs/pyflink-quickstart/lib/python3.7/site-packages/py4j/java_collections.py:13 >>>>> >>>>> /usr/local/anaconda3/envs/pyflink-quickstart/lib/python3.7/site-packages/py4j/java_collections.py:13: >>>>> DeprecationWarning: Using or importing the ABCs from 'collections' instead >>>>> of from 'collections.abc' is deprecated since Python 3.3,and in 3.9 it >>>>> will >>>>> stop working >>>>> from collections import ( >>>>> >>>>> >>>>> ../../../../../usr/local/anaconda3/envs/pyflink-quickstart/lib/python3.7/site-packages/pyflink/table/udf.py:291 >>>>> >>>>> /usr/local/anaconda3/envs/pyflink-quickstart/lib/python3.7/site-packages/pyflink/table/udf.py:291: >>>>> DeprecationWarning: Using or importing the ABCs from 'collections' instead >>>>> of from 'collections.abc' is deprecated since Python 3.3,and in 3.9 it >>>>> will >>>>> stop working >>>>> if not isinstance(input_types, collections.Iterable) \ >>>>> >>>>> -- Docs: https://docs.pytest.org/en/stable/warnings.html >>>>> ====================================================================================== >>>>> 1 passed, 6 warnings in 0.98s >>>>> ======================================================================================= >>>>> ``` >>>>> >>>>> However, the test will fail as expected if I remove the >>>>> `@udf(input_types=[...], result_type=...)` annotation: >>>>> ``` >>>>> > pytest >>>>> =========================================================================================== >>>>> test session starts >>>>> ============================================================================================ >>>>> platform darwin -- Python 3.7.10, pytest-6.2.2, py-1.10.0, >>>>> pluggy-0.13.1 >>>>> rootdir: /Users/chenyisheng/source/yiksanchan/pytest-flink >>>>> collected 1 item >>>>> >>>>> tests/test_helloworld.py F >>>>> >>>>> [100%] >>>>> >>>>> ================================================================================================= >>>>> FAILURES >>>>> ================================================================================================= >>>>> _________________________________________________________________________________________________ >>>>> test_add >>>>> _________________________________________________________________________________________________ >>>>> >>>>> def test_add(): >>>>> > assert add(1,1) == 3 >>>>> E assert 2 == 3 >>>>> E + where 2 = add(1, 1) >>>>> >>>>> tests/test_helloworld.py:4: AssertionError >>>>> ============================================================================================= >>>>> warnings summary >>>>> ============================================================================================= >>>>> >>>>> ../../../../../usr/local/anaconda3/envs/pyflink-quickstart/lib/python3.7/site-packages/py4j/java_collections.py:13 >>>>> >>>>> ../../../../../usr/local/anaconda3/envs/pyflink-quickstart/lib/python3.7/site-packages/py4j/java_collections.py:13 >>>>> >>>>> ../../../../../usr/local/anaconda3/envs/pyflink-quickstart/lib/python3.7/site-packages/py4j/java_collections.py:13 >>>>> >>>>> ../../../../../usr/local/anaconda3/envs/pyflink-quickstart/lib/python3.7/site-packages/py4j/java_collections.py:13 >>>>> >>>>> ../../../../../usr/local/anaconda3/envs/pyflink-quickstart/lib/python3.7/site-packages/py4j/java_collections.py:13 >>>>> >>>>> /usr/local/anaconda3/envs/pyflink-quickstart/lib/python3.7/site-packages/py4j/java_collections.py:13: >>>>> DeprecationWarning: Using or importing the ABCs from 'collections' instead >>>>> of from 'collections.abc' is deprecated since Python 3.3,and in 3.9 it >>>>> will >>>>> stop working >>>>> from collections import ( >>>>> >>>>> -- Docs: https://docs.pytest.org/en/stable/warnings.html >>>>> ========================================================================================= >>>>> short test summary info >>>>> ========================================================================================== >>>>> FAILED tests/test_helloworld.py::test_add - assert 2 == 3 >>>>> ====================================================================================== >>>>> 1 failed, 5 warnings in 0.17s >>>>> ======================================================================================= >>>>> ``` >>>>> >>>>> The full example can be found >>>>> https://github.com/YikSanChan/how-to-pytest-flink. >>>>> >>>>> Best, >>>>> Yik San >>>>> >>>>
