valid8r.testing

Testing utilities for Valid8r.

This module provides tools for testing applications that use Valid8r, making it easier to test validation logic, user prompts, and Maybe monads.

Submodules

• valid8r.testing.assertions
• valid8r.testing.generators
• valid8r.testing.mock_input

Functions

assert_maybe_failure(result, expected_error)	Assert that a Maybe is a Failure with the expected error message.
assert_maybe_success(result, expected_value)	Assert that a Maybe is a Success with the expected value.
generate_random_inputs(validator[, count, range_min, ...])	Generate random inputs that include both valid and invalid cases.
generate_test_cases(validator)	Generate test cases for a validator.
test_validator_composition(validator)	Test a composed validator with various inputs to verify it works correctly.
MockInputContext([inputs])	Context manager for mocking user input.
configure_mock_input(inputs)	Configure input to be mocked globally.

Package Contents

valid8r.testing.assert_maybe_failure(result, expected_error)

Assert that a Maybe is a Failure with the expected error message.

Parameters:

• result (valid8r.core.maybe.Maybe[T]) – The Maybe instance to check

• expected_error (str) – The expected error message inside the Maybe

Returns:

True if result is a Failure with the expected error, False otherwise

Return type:

bool

Examples

>>> result = Maybe.failure("Invalid input")
>>> assert_maybe_failure(result, "Invalid input")
True
>>> assert_maybe_failure(result, "Other error")
False

valid8r.testing.assert_maybe_success(result, expected_value)

Assert that a Maybe is a Success with the expected value.

Parameters:

• result (valid8r.core.maybe.Maybe[T]) – The Maybe instance to check

• expected_value (Any) – The expected value inside the Maybe

Returns:

True if result is a Success with the expected value, False otherwise

Return type:

bool

Examples

>>> result = Maybe.success(42)
>>> assert_maybe_success(result, 42)
True
>>> assert_maybe_success(result, 43)
False

valid8r.testing.generate_random_inputs(validator, count=20, range_min=-100, range_max=100)

Generate random inputs that include both valid and invalid cases.

Parameters:

• validator (valid8r.core.validators.Validator[T]) – The validator to test against

• count (int) – Number of inputs to generate

• range_min (int) – Minimum value for generated integers

• range_max (int) – Maximum value for generated integers

Returns:

A list of random integers

Return type:

list[T]

Examples

>>> from valid8r.core.validators import minimum
>>> inputs = generate_random_inputs(minimum(0), count=10)
>>> len(inputs)
10

valid8r.testing.generate_test_cases(validator)

Generate test cases for a validator.

This function analyzes the validator and generates appropriate test cases that should pass and fail the validation.

Parameters:

validator (valid8r.core.validators.Validator[T]) – The validator to generate test cases for

Returns:

A dictionary with ‘valid’ and ‘invalid’ lists of test cases

Return type:

dict[str, list[Any]]

Examples

>>> from valid8r.core.validators import minimum
>>> test_cases = generate_test_cases(minimum(10))
>>> test_cases
{'valid': [10, 11, 15, 20, 100], 'invalid': [9, 5, 0, -10]}

valid8r.testing.test_validator_composition(validator)

Test a composed validator with various inputs to verify it works correctly.

Parameters:

validator (valid8r.core.validators.Validator[T]) – The composed validator to test

Returns:

True if the validator behaves as expected, False otherwise

Return type:

bool

Examples

>>> from valid8r.core.validators import minimum, maximum
>>> is_valid_age = minimum(0) & maximum(120)
>>> test_validator_composition(is_valid_age)
True

valid8r.testing.MockInputContext(inputs=None)

Context manager for mocking user input.

Parameters:

inputs (list[str] | None) – A list of strings to be returned sequentially by input().

Yields:

None

Return type:

collections.abc.Iterator[None]

Examples

>>> with MockInputContext(["yes", "42"]):
...     answer = input("Continue? ")  # returns "yes"
...     number = input("Enter number: ")  # returns "42"

valid8r.testing.configure_mock_input(inputs)

Configure input to be mocked globally.

Unlike MockInputContext, this function replaces the input function globally without restoring it automatically. Use for simple tests where cleanup isn’t critical.

Parameters:

inputs (list[str]) – A list of strings to be returned sequentially by input().

Return type:

None

Examples

>>> configure_mock_input(["yes", "42"])
>>> answer = input("Continue? ")  # returns "yes"
>>> number = input("Enter number: ")  # returns "42"