asserts

0.14.0 verified Mon Apr 27 auth: no python

A standalone assertions library providing a rich set of assertion functions beyond unittest, with support for JSON subset checking, datetime assertions, regex, and context managers. Current version 0.14.0, requires Python >=3.10, released irregularly.

pip install asserts

Common errors

error ModuleNotFoundError: No module named 'asserts' ↓

cause Package not installed.

fix

Run 'pip install asserts'.

error TypeError: 'AssertRaisesContext' object is not callable ↓

cause Using assert_raises as a decorator instead of context manager.

fix

Use with assert_raises(ExcType): ...

error AttributeError: module 'asserts' has no attribute 'Exists' ↓

cause Exists was renamed to Present in 0.13.0.

fix

Use 'from asserts import Present' and replace Exists with Present.

Warnings

breaking Python 3.8 and 3.9 support dropped in 0.14.0. Requires Python >=3.10. ↓

fix Upgrade to Python 3.10+ or pin asserts<0.14.0.

deprecated Exists is deprecated since 0.13.0; use Present or Absent instead. ↓

fix Replace Exists with Present for existence or Absent for non-existence.

gotcha assert_raises and assert_warns are context managers, not decorators. Must use 'with' statement. ↓

fix Use 'with assert_raises(Exception):' pattern.

breaking assert_datetime_about_now and assert_datetime_about_now_utc now raise AssertionError instead of TypeError for timezone-aware datetimes. ↓

fix Ensure datetime arguments are naive or adjust exception handling.

Imports

assert_equals
wrong
```
from asserts.asserts import assert_equals
```
correct
```
from asserts import assert_equals
```
asserts is a flat namespace, not a package with submodules.

assert_raises

wrong

from asserts import assert_raises as * or from unittest import assertRaises

correct

from asserts import assert_raises

assert_raises is a context manager, not a function returning bool.

Present
wrong
```
from asserts import Exists
```
correct
```
from asserts import Present
```
Exists is deprecated since 0.13.0 in favor of Present and Absent.
assert_json_subset
```
from asserts import assert_json_subset
```
for checking JSON objects are subsets.

Quickstart

Basic usage: use assert_equals for equality, assert_raises as a context manager for exception testing.

from asserts import assert_equals, assert_raises

def test_addition():
    assert_equals(2 + 2, 4)

with assert_raises(ValueError):
    int('abc')