This directory contains property-based tests using a library called Hypothesis.

The property tests for xarray are a work in progress - more are always welcome. They are stored in a separate directory because they tend to run more examples and thus take longer, and so that local development can run a test suite without needing to pip install hypothesis.

Instead of making assertions about operations on a particular piece of data, you use Hypothesis to describe a kind of data, then make assertions that should hold for any example of this kind.

For example: "given a 2d ndarray of dtype uint8 arr, xr.DataArray(arr).plot.imshow() never raises an exception".

Hypothesis will then try many random examples, and report a minimised failing input for each error it finds. See the docs for more info.