pytest-expect-test

0.1.0 verified Sat May 09 auth: no python

A lightweight pytest plugin providing an `expect` fixture for snapshot testing. Version 0.1.0 is the initial release, requiring Python >=3.5. Development appears low-frequency, with no recent updates.

pip install pytest-expect-test

Common errors

error ImportError: cannot import name 'expect' ↓

cause Attempting to import `expect` directly from `pytest` or without installing the plugin.

fix

Run pip install pytest-expect-test and use from pytest_expect_test import expect.

error AttributeError: 'Test' object has no attribute 'expect' ↓

cause Using `self.expect` inside a test method in a class while `expect` is passed as a parameter. Not supported as class attribute.

fix

Use expect as a function parameter in the test method: def test_example(self, expect): expect(...)

Warnings

gotcha On first test run, the test passes regardless of the actual value because the expectation is recorded. Subsequent runs will fail if the actual value differs from recorded. ↓

fix Review the recorded expectations (typically stored in test directory) and commit them to version control.

gotcha The `expect` fixture must be used as a parameter in the test function; it is not a regular assertion. Do not call `expect()` as a function without the fixture injection. ↓

fix Define test with `def test_foo(expect):` to inject the fixture.

Imports

expect
wrong
```
import pytest_expect_test
```
correct
```
from pytest_expect_test import expect
```
Direct import of the module gives pytest plugin; the fixture needs explicit import.

Quickstart

Basic usage: use the `expect` fixture to assert equality. On first run, the expected value is recorded; later runs check against the recorded snapshot.

def test_example(expect):
    expect(2 + 2) == 4
    # The first run records the expectation, subsequent runs compare.