Demo for python-attrs/attrs#795

.gitignore

micromamba
.conda
node_modules

custom.py

from attr import attrib, field, define

def custom_define(*args, **kwargs):
    return attr.define(*args, **kwargs)

custom.pyi

from typing import Any, Callable, Tuple, TypeVar, Union

from attr import attrib, define, field

_T = TypeVar("_T")


def __dataclass_transform__(
    *,
    eq_default: bool = True,
    order_default: bool = False,
    kw_only_default: bool = False,
    field_descriptors: Tuple[Union[type, Callable[..., Any]], ...] = (()),
) -> Callable[[_T], _T]:
    ...


@__dataclass_transform__(field_descriptors=(attrib, field))
def custom_define(*args, **kwargs):
    ...

environment.yml

channels:
  - conda-forge
dependencies:
  - attrs
  - python=3.9
  - nodejs
  - mypy=0.812

mypy

.conda/bin/mypy

npm

.conda/bin/npm

package-lock.json

{
  "name": "cd3c8ebbf245df6c3666eec0852c171d",
  "lockfileVersion": 2,
  "requires": true,
  "packages": {
    "": {
      "dependencies": {
        "pyright": "^1.1.134"
      }
    },
    "node_modules/pyright": {
      "version": "1.1.134",
      "resolved": "https://registry.npmjs.org/pyright/-/pyright-1.1.134.tgz",
      "integrity": "sha512-wQSdU6X3olAwCZy3tSA0fn8nMQGEwm01rm1dHM+aN2crzXIcUQ9sLOf+wCn5PFlLGsm/CXH7ROYmeMs3jXQ8Rw==",
      "bin": {
        "pyright": "index.js",
        "pyright-langserver": "langserver.index.js"
      },
      "engines": {
        "node": ">=12.0.0"
      }
    }
  },
  "dependencies": {
    "pyright": {
      "version": "1.1.134",
      "resolved": "https://registry.npmjs.org/pyright/-/pyright-1.1.134.tgz",
      "integrity": "sha512-wQSdU6X3olAwCZy3tSA0fn8nMQGEwm01rm1dHM+aN2crzXIcUQ9sLOf+wCn5PFlLGsm/CXH7ROYmeMs3jXQ8Rw=="
    }
  }
}

package.json

{
  "dependencies": {
    "pyright": "^1.1.134"
  }
}

pyright

node_modules/pyright/index.js

pyright_extension_demo.md

Expected

Demo of microsoft/pyright#1782 with custom wrapper. Adding __dataclass_transform__ in .pyi.

Expected output:

+ ./mypy test.py
test.py:9: note: Revealed type is 'def (self: builtins.object)'
+ ./pyright test.py
No configuration file found.
No pyproject.toml file found.
stubPath /home/alexford/pyright_test_attrs/typings is not a valid directory.
Assuming Python platform Linux
Searching for source files
Found 1 source file
/home/alexford/pyright_test_attrs/test.py
  /home/alexford/pyright_test_attrs/test.py:9:13 - info: Type of "Data.__init__" is "(self: Data, a: str, b: int) -> None"
0 errors, 0 warnings, 1 info
Completed in 0.786sec

setup_and_run

#!/usr/bin/env python

import sys
import subprocess

def check_call(cmd):
    print("+ " + cmd)
    subprocess.check_call(cmd, shell=True)

def call(cmd):
    print("+ " + cmd)
    subprocess.call(cmd, shell=True)

url = {
    "linux": "https://micromamba.snakepit.net/api/micromamba/linux-64/latest",
    "darwin": "https://micromamba.snakepit.net/api/micromamba/osx-64/latest"
}[sys.platform]

check_call("wget -qO- " + url + " | tar -xvj bin/micromamba")
check_call("mv bin/micromamba micromamba")
check_call("rmdir bin")

check_call("./micromamba create --prefix ./.conda --file environment.yml")
check_call("./npm install pyright")

call("./mypy test.py")
call("./pyright test.py")

test.py

import attr
from custom import custom_define

@custom_define
class Data:
    a: str
    b: int = attr.field()

reveal_type(Data.__init__)