Add Mypy configuration through root "pyproject.toml" file #135

Delgan · 2023-11-04T22:11:31Z

Hi!

This is a proposal to fix #133.

This offers a way to use Mypy configuration specific to tests without needing the --mypy-pyproject-toml-file command line argument. Instead, users can define a [tool.pytest-mypy-plugins.mypy-config] table in their repository's pyproject.toml file.

This approach addresses two issues:

Avoids the need for an extra file in the repository to store Mypy test configuration.
Ensures that pytest can be invoked from any location (this is not possible when --mypy-pyproject-toml-file is specified via the addopts configuration, as paths are resolved relative to the current working directory).

The order of precedence for Mypy configuration is as follows, with each subsequent option taking precedence over the previous ones if it exists:

Use configuration from [tool.pytest-mypy-plugins.mypy-config] in the root pyproject.toml as default.
Override default with options from --mypy-pyproject-toml-file or --mypy-ini-file if provided.
Override again with config_mypy section in a test if present.

I hope this process isn't too convoluted. Please let me know if you prefer a different approach. I made slight modifications to the join_toml_configs() function to implement the rules mentioned above. Additionally, I can add more unit tests if necessary.

Delgan · 2023-11-04T22:23:30Z

.github/workflows/test.yml

@@ -26,6 +26,8 @@ jobs:
      run: |
        pip install -U pip setuptools wheel
        pip install -e .
+        # Workaround until Mypy regression is fixed.
+        pip install mypy==1.5.1


This is unrelated to the other changes I made.
Current master branch is failing with latest version of Mypy for a reason I'm not sure to understand.

Can you please provide a traceback?

@sobolevn Sure:

$ pytest pytest_mypy_plugins/tests/test-mypy-config.yml -vvv ============================================================================== test session starts ============================================================================== platform linux -- Python 3.11.5, pytest-7.4.3, pluggy-1.3.0 -- /home/delgan/programming/pytest-mypy-plugins/env/bin/python cachedir: .pytest_cache rootdir: /home/delgan/programming/pytest-mypy-plugins configfile: pyproject.toml plugins: mypy-plugins-3.0.0 collected 1 item pytest_mypy_plugins/tests/test-mypy-config.yml::custom_mypy_config_strict_optional_true_set FAILED =================================================================================== FAILURES ==================================================================================== __________________________________________________________________ custom_mypy_config_strict_optional_true_set __________________________________________________________________ /home/delgan/programming/pytest-mypy-plugins/pytest_mypy_plugins/tests/test-mypy-config.yml:4: E pytest_mypy_plugins.utils.TypecheckAssertionError: Output is not expected: E Actual: E ../../home/delgan/programming/pytest-mypy-plugins/env/lib/python3.11/site-packages/mypy/typeshed/stdlib/builtins.pyi:154: error: Overloaded function signature 2 will never be matched: signature 1's parameter type(s) are the same or broader [misc] (diff) E Expected: E (empty) ============================================================================ short test summary info ============================================================================ FAILED pytest_mypy_plugins/tests/test-mypy-config.yml::custom_mypy_config_strict_optional_true_set - =============================================================================== 1 failed in 3.14s ===============================================================================

This can be reproduced by executing mypy --no-silence-site-packages --no-strict-optional on the following file:

from typing import Optional a: Optional[int] = None a + 1 # should not raise an error

Mypy v1.6.0+ flags this snippet as invalid and exits with non-zero:

env/lib/python3.11/site-packages/mypy/typeshed/stdlib/builtins.pyi:154: error: Overloaded function signature 2 will never be matched: signature 1's parameter type(s) are the same or broader [misc] Found 1 error in 1 file (checked 1 source file)

This doesn't happen when --no-silence-site-packages is omitted.

--no-strict-optional is not tested much in mypy (and for a good reason - it should not be used).

How does it affect us here?

It is used to verify that inline mypy_config works as expected: https://github.com/typeddjango/pytest-mypy-plugins/blob/master/pytest_mypy_plugins/tests/test-mypy-config.yml

We can probably test it with another option, though.

I stumbled upon this pr because tests failed with mypy-1.8.0 (https://bugs.gentoo.org/921901). (Where) has the regression been reported upstream?

sobolevn

This is not a full review for now :)

sobolevn · 2023-11-05T07:46:12Z

README.md

@@ -195,6 +195,16 @@ mypy-tests:

 ```

+## Configuration
+
+For convenience, it is also possible to define a default `mypy` configuration in the root `pyproject.toml` file of your project:


Please, also describe what priority this setting has over CLI flags / etc.

sobolevn · 2023-11-05T07:50:03Z

pytest_mypy_plugins/tests/test_configs/test_join_toml_configs.py

@@ -54,7 +61,7 @@ def factory(filename: Optional[str], expected: str) -> None:
 def test_join_existing_config(
    execution_path: Path, assert_file_contents: _AssertFileContents, additional_config: str
 ) -> None:
-    filepath = join_toml_configs(_PYPROJECT1, additional_config, execution_path)
+    filepath = join_toml_configs(_MYPY_PLUGINS_CONFIG2, _PYPROJECT1, additional_config, execution_path)


Let's please keep existing tests as-is :)

Because of the new implementation, I had no other choice but to add a new parameter to join_toml_configs(), and consequently I had to update the tests. What alternative approach would you suggest?

Maybe add a default?

Fine. 👍

Also, to test precedence, I added a parameter to the pyproject1.toml:

pytest-mypy-plugins/pytest_mypy_plugins/tests/test_configs/pyproject1.toml

Line 7 in 050fb9b

show_error_context = true

Consequently, the output of some existing tests changed as well:

pytest-mypy-plugins/pytest_mypy_plugins/tests/test_configs/test_join_toml_configs.py

Line 99 in 050fb9b

show_error_codes = false

Do you want this to be reverted as well?

Yes, please. I am asking this, because I want to make sure it won't affect existing use-cases for existing users.

sobolevn · 2023-11-05T07:51:41Z

pytest_mypy_plugins/tests/test_configs/root_pyproject2.toml

@@ -0,0 +1 @@
+# This file has no `[tool.pytest-mypy-plugins.mypy-config]` existing config


We can just update the comment in https://github.com/typeddjango/pytest-mypy-plugins/blob/master/pytest_mypy_plugins/tests/test_configs/pyproject2.toml

No need to create two empty files.

sobolevn · 2023-11-05T07:55:08Z

Thanks a lot!

Delgan · 2023-11-05T21:52:04Z

@sobolevn I updated the PR according to your comments. 👍

Two remarks waiting for your opinion:

maybe I should rename the mypy-config table to config-mypy for consistency with the existing inline field.
I could also add tests for join_ini_configs() but I don't know what are your preferences regarding the assert_file_contents() utils function (should it be duplicated, or what is the common file where I should move it).

It is not uncommon to require a Mypy configuration that differs from the project's main configuration and is specific to tests, such as enabling the 'force_uppercase_builtins' option. Currently, the argument '--mypy-pyproject-toml-file' can be used via the command line, but this approach has two drawbacks: - It requires an additional file in the codebase, whereas it is more pleasant to group all configurations in the root 'pyproject.toml' file. - It confines the invocation of 'pytest' to a fixed location, as the path is resolved relative to the current working directory. However, there are situations where it is useful to call 'pytest' from a different directory. The solution implemented here allows for configuring the Mypy parameters used by 'pytest-mypy-plugins' directly within the project's 'pyproject.toml' file, addressing both of the aforementioned points.

Delgan force-pushed the GH-133-add-plugin-config branch 2 times, most recently from ea61ad5 to 050fb9b Compare November 4, 2023 22:21

Delgan commented Nov 4, 2023

View reviewed changes

sobolevn reviewed Nov 5, 2023

View reviewed changes

Delgan force-pushed the GH-133-add-plugin-config branch 2 times, most recently from 3ec2297 to e7b7a9d Compare November 5, 2023 21:48

Delgan force-pushed the GH-133-add-plugin-config branch from e7b7a9d to 0f10c94 Compare November 5, 2023 21:54

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Add Mypy configuration through root "pyproject.toml" file #135

Add Mypy configuration through root "pyproject.toml" file #135

Delgan commented Nov 4, 2023

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sobolevn Nov 5, 2023

Delgan Nov 5, 2023

sobolevn Nov 5, 2023

Delgan Nov 5, 2023

antecrescent Jan 15, 2024 •

edited

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sobolevn commented Nov 5, 2023

Delgan commented Nov 5, 2023

		@@ -0,0 +1 @@
		# This file has no `[tool.pytest-mypy-plugins.mypy-config]` existing config

Add Mypy configuration through root "pyproject.toml" file #135

Are you sure you want to change the base?

Add Mypy configuration through root "pyproject.toml" file #135

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Delgan commented Nov 4, 2023

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antecrescent Jan 15, 2024 • edited

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sobolevn commented Nov 5, 2023

Delgan commented Nov 5, 2023

antecrescent Jan 15, 2024 •

edited