overrides-extension 3.2.3

A decorator to automatically detect mismatch when overriding a method.

A decorator to automatically detect mismatch when overriding a method. See http://stackoverflow.com/questions/1167617/in-python-how-do-i-indicate-im-overriding-a-method

All checks are done when a class or a method is created and not when a method is executed or an instance of a class is created. This means that performance implications are minimal.

Note: Version 2.8.0 is the last one that supports Python 2.7. Versions after that work with Python >= 3.6.

Copyright Disclaimer

Please note, this repository and published pip package is a fork of the original implementation. It’s being distributed separately as it breaks backward compatibility with previous versions.

Why explicit overrides?

Overrides without explicit indicator for them are weak. They leave room for problems that happen during the evolution of a codebase.

1. (create) Accidental overriding in a subclass when a method to a superclass is added (or vice versa).

2. (modify) Rename of a superclass method without subclass method rename (or vice versa).

3. (delete) Deleting of a superclass method without detecting in subclass that the method is not anymore overriding anything (or vice versa).

These might happen for example when overriding a method in a module that does not live in your codebase, or when merging changes done by someone else to the codebase without having access to your subclass.

Installation

$ pip install overrides-extension

Usage

from overrides_extension import override


class SuperClass:
    def method(self) -> int:
        """This is the doc for a method and will be shown in subclass method too!"""
        return 2


class SubClass(SuperClass):
    @override
    def method(self) -> int:
        return 1

Enforcing usage

from overrides_extension import EnforceOverrides, final, override


class SuperClass(EnforceOverrides):
    @final
    def method(self) -> int:
        """This is the doc for a method and will be shown in subclass method too!"""
        return 2

    def method2(self) -> int:
        """This is the doc for a method and will be shown in subclass method too!"""
        return 2

    @staticmethod
    def method3() -> int:
        """This is the doc for a method and will be shown in subclass method too!"""
        return 2


# THIS FAILS
class SubClass1(SuperClass):
    def method(self) -> int: # <-- overriding a final method
        return 1


# THIS FAILS
class SubClass2(SuperClass):
    def method2(self) -> int: # <-- @override decorator missing
        return 1


# THIS ONE IS OK
class SubClass3(SuperClass):
    @override
    def method2(self) -> int:
        return 1


# ENSURE THAT @classmethod AND @staticmethod ARE PLACED AT THE TOP
class SubClass4(SuperClass):
    @staticmethod
    @override
    def method3() -> int:
        return 1

Contributors

This project becomes a reality only through the work of all the people who contribute.

mkorpela, drorasaf, ngoodman90, TylerYep, leeopop, donpatrice, jayvdb, joelgrus, lisyarus, soulmerge, rkr-at-dbx, mozharovsky