Doing dirty (but extremely useful) things with equals.
MIT License
Documentation: dirty-equals.helpmanual.io
Source Code: github.com/samuelcolvin/dirty-equals
dirty-equals is a python library that (mis)uses the __eq__
method to make python code (generally unit tests)
more declarative and therefore easier to read and write.
dirty-equals can be used in whatever context you like, but it comes into its own when writing unit tests for applications where you're commonly checking the response to API calls and the contents of a database.
Here's a trivial example of what dirty-equals can do:
from dirty_equals import IsPositive
assert 1 == IsPositive
assert -2 == IsPositive # this will fail!
That doesn't look very useful yet!, but consider the following unit test code using dirty-equals:
from dirty_equals import IsJson, IsNow, IsPositiveInt, IsStr
...
# user_data is a dict returned from a database or API which we want to test
assert user_data == {
# we want to check that id is a positive int
'id': IsPositiveInt,
# we know avatar_file should be a string, but we need a regex as we don't know whole value
'avatar_file': IsStr(regex=r'/[a-z0-9\-]{10}/example\.png'),
# settings_json is JSON, but it's more robust to compare the value it encodes, not strings
'settings_json': IsJson({'theme': 'dark', 'language': 'en'}),
# created_ts is datetime, we don't know the exact value, but we know it should be close to now
'created_ts': IsNow(delta=3),
}
Without dirty-equals, you'd have to compare individual fields and/or modify some fields before comparison - the test would not be declarative or as clear.
dirty-equals can do so much more than that, for example:
IsPartialDict
IsStrictDict
IsList
andIsTuple
IsInstance
|
and &
to combine multiple conditionsSimply:
pip install dirty-equals
dirty-equals requires Python 3.8+.