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 >
