snaptol 0.0.1

A Python tool for snapshot testing with numerical tolerance on floating point numbers

snaptol

A Python tool for snapshot testing with numerical tolerance on floating point numbers.

Installation

Use the package manager pip to install snaptol.

pip install snaptol

Usage

Normal usage

In a test file, add the snapshot fixture, snaptolshot,

def test_something(snaptolshot):
    result = compute_something()
    assert snaptolshot == result

When pytest runs, it will compare the result to the snapshot stored in file.

To provide a tolerance, pass it as an argument to the fixture,

def test_something(snaptolshot):
    result = compute_something()
    assert snaptolshot(rtol=1e-05, atol=1e-08) == result

Alternatively, use the match method,

def test_something(snaptolshot):
    result = compute_something()
    assert snaptolshot.match(rtol=1e-05, atol=1e-08) == result

Updating snapshots

On initial pass and subsequent changes to the test, run pytest with the --snapshot-update flag,

pytest --snapshot-update

This will not perform the comparison between snapshot and result, but rather update the snapshot file with the current result.

Contributing

Pull requests are welcome. For major changes, please open an issue first to discuss what you would like to change.

Please make sure to update tests as appropriate.

License

MIT