callee

library0.3.1pypypi✓ verified 86d ago

Callee provides a set of powerful argument matchers designed to extend the capabilities of Python's `unittest.mock` library. It allows developers to write more expressive and robust assertions for mocked calls, enabling checks for patterns, types, ranges, and more, beyond simple value equality. The current version is 0.3.1, with a stable but infrequent release cadence.

testing

pip install callee

github ↗package ↗

INSTALL

IMPORT

SIG · CALLEE

callee

testingpythonv0.3.1

Install

2.4s avg

Import

228ms

Disk

17MB

Pass rate

10/ 10

Env Coverage10 / 10

glibc

3.9–3.13

musl

3.9–3.13

Install & Compatibility

Where this runs

tested against v0.3.1 · pip install

no network on importno background threads

Install × environment matrix

Each cell = how many times install + import succeeded across repeated harness runs. Partial = flaky.
glibc = Debian/Ubuntu slim · musl = Alpine Linux

musl

py 3.10–3.910 runs

installs and imports cleanly · install 0.0s · import 0.242s · 19.3MB

glibc

py 3.10–3.910 runs

installs and imports cleanly · install 2.4s · import 0.214s · 20MB

17MB installed

● package 17MB

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

Any

✓ from callee import Any

✗ from unittest.mock import ANY

callee.Any allows for type-specific matching (e.g., Any(int)), while unittest.mock.ANY is a generic singleton for 'any value'.

✓ from callee import Eq

Regex

✓ from callee import Regex

InstanceOf

✓ from callee import InstanceOf

Not

✓ from callee import Not

This quickstart demonstrates how to use `callee` matchers with `unittest.mock` to assert more complex argument patterns. It creates a mock object, calls a function that uses it, and then uses `Eq`, `Regex`, and `Any` matchers within `assert_has_calls` to verify the arguments passed to the mock.

from unittest import mock from callee import Eq, Regex, Any class MyService: def process_data(self, data_id, name): # Imagine this does something with data_id and name return f"Processed {name} with ID {data_id}" def external_function(service: MyService): # This function calls methods on the provided service service.process_data(123, "test_name_abc") service.process_data(456, "another_name_xyz") # Create a mock for MyService mock_service = mock.Mock(spec=MyService) # Call the function that uses the service, injecting our mock external_function(mock_service) # Assert that process_data was called with specific matchers # This checks the first call mock_service.process_data.assert_has_calls([ mock.call(Eq(123), Regex(r'^test_name_.*$')), mock.call(Any(int), Any(str)) # Any integer, any string for the second call ]) print("Assertions successful!")

Debug

Known issues

breakingVersion 0.3.0 introduced breaking changes: The `class_of` matcher was removed (use `InstanceOf` instead). The `call_has_args` and `call_has_kwargs` methods were renamed to `call_args_are` and `call_kwargs_are` respectively.

fix

Update your code to use `InstanceOf` instead of `class_of` and `call_args_are`/`call_kwargs_are` instead of their deprecated names.

affects: >=0.3.0

gotcha`callee` matchers are primarily designed for use within `unittest.mock`'s assertion methods (e.g., `assert_called_with`, `assert_has_calls`, checking `call_args`). They are not general-purpose assertion objects and should not be used directly in standard Python `assert` statements (e.g., `assert 'foo' == Regex(r'foo')` will likely fail or behave unexpectedly) as they rely on `unittest.mock`'s internal comparison logic.

fix

Ensure `callee` matchers are passed as arguments to `unittest.mock` assertion methods, or used when inspecting `mock.call_args` through `callee.matchers.Matching(...)` if custom logic is required outside standard assertions.

affects: All

gotchaBe mindful of the distinction between `callee.Any` and `unittest.mock.ANY`. While both signify 'any argument', `callee.Any` offers more advanced capabilities, such as specifying a type (e.g., `Any(int)`) or other conditions, making it more powerful for precise matching. `unittest.mock.ANY` is a simple singleton for any value.

fix

Use `callee.Any` when you need to specify a type or apply additional conditions to 'any' argument. Use `unittest.mock.ANY` for a generic 'don't care' placeholder.

affects: All

Errors

Common errors & fixes

TypeError: argument of type 'Regex' is not iterable

Attempting to use a `callee` matcher directly in a comparison or context where `unittest.mock`'s evaluation logic is not present, such as `assert 'some_string' == Regex(r'some.*')`.

fix

Ensure `callee` matchers are always passed as arguments to `unittest.mock` assertion methods, like `mock_obj.assert_called_with(Regex(r'some.*'))`.

AssertionError: Expected call: call(<callee.matchers.Eq object at 0x...>) Actual call: call(6)

This `AssertionError` from `unittest.mock` indicates that an expected `callee` matcher (e.g., `Eq(5)`) did not match the actual argument passed to the mock (e.g., `6`). The error message shows the matcher object because it represents the expectation that failed.

fix

Review the actual values being passed to the mock during the test run and compare them against the conditions defined by your `callee` matchers. Adjust either the test data or the matcher's expectation to align.

NameError: name 'Any' is not defined

The `Any` matcher (or any other `callee` matcher) was used without being correctly imported from the `callee` library.

fix

Add the necessary import statement at the top of your file: `from callee import Any` (or other specific matchers).

Upgrade

Version history

0.3.1latest on PyPI · released Dec 24, 2019

Audit

Dependencies

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Agent activity

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Resources

githubhttps://github.com/Xion/callee ↗

packagehttps://pypi.org/project/callee/ ↗