GEE Filesystem

Generate a test file tree in GEE

Using the pytest_gee plugin, you can easily generate a test file tree in GEE that will be used to run your tests. This tree will start in a folder named with the gee_hash fixture and will be deleted at the end of the test session.

By using this method you will ensure that the folder you are using for your test is unique and that it will not interfere with other tests (e.g. parallel tests).

# test_something.py

def test_something(gee_hash, gee_folder_root, gee_test_folder):
    # this folder is existing within your GEE account and will be deleted at the end of the test session
    print(gee_folder_root)

Warning

To avoid piling up fake folder in your GEE account, make sure to let the test reach the end of the session. It means that you should never cancel a session with ctrl+c or by killing the process.

Customize the test folder tree

By default the test folder tree is empty and will be deleted at the end of the test session. You can decide to populate it with some assets that will be used in your tests.

To do so customize the gee_folder_structure fixture in your conftest.py file. This fixture is a dict that will be used to create the folder tree in GEE. First you can create containers assets (namely folders or image collections) to store your assets. These container are simply marked as keys in the dict and specify their types after a “::” symbol as shown in the following example. assets need to be ee.Image or ee.FeatureCollection objects and remaining small as the creation operation is taken care of by the plugin. Specifically for ee.Image objects, please use the clipToBoundsAndScale method to make sure the asset has a geometry and a scale.

# conftest.py

import pytest

@pytest.fixture(scope="session")
def gee_folder_structure():
    """Override the default test folder structure."""
    point = ee.Geometry.Point([0, 0])
    return {
        "folder::Folder": {
            "image": ee.Image(1).clipToBoundsAndScale(point.buffer(100), scale=30),
            "fc": ee.FeatureCollection(point),
        },
        "image_collection::ImageCollection": {
            "image1": ee.Image(1).clipToBoundsAndScale(point.buffer(100), scale=30),
            "image2": ee.Image(1).clipToBoundsAndScale(point.buffer(100), scale=30),
        }
    }

Which will render in your GEE account as:

8d98a5be574041a6a54d6def9d915c67/
└── folder/
    ├── fc (FeatureCollection)
    └── image (Image)
└── image_collection/ (ImageCollection)
    ├── image1 (Image)
    └── image2 (Image)

Customize the root folder

By default the test folder will be created at the root of the user account. There are situation where one could prefer to store it in a specific folder.

To do so customize the gee_folder_root fixture in your conftest.py file, simply return the asset id of the folder you want to use as root.

# conftest.py

import pytest

@pytest.fixture(scope="session")
def gee_folder_root():
    """Override the default test folder root."""
    return "project/username/assets/my_root_folder"

Note

This is compulsory if you use a service account to connect to GEE as the service account has no associated root folder.

Create assets

Most of tests pipelines are checking different python versions in parallel which can create multiple issues from a GEE perspective:

• The assets names need to be unique

• The tasks names also need to be unique

To avoid this issue, the plugin is shipped with a session wise unique hex fixture gee_hash that can be used to suffix or prefix your assets and tasks names. To make sure the asset exist when you run your tests, you can use the pytest_gee.wait method to wait until the asset is effectively generated.

# test.py

import pytest
import pytest_gee


def test_create_asset(gee_hash):
    # create an asset name
    asset_name = f"asset_{gee_hash}"

    # export the an object to this asset
    task = ee.batch.Export.image.toAsset(
        image=ee.Image(1),
        description=asset_name,
        assetId=asset_name,
        scale=1,
        maxPixels=1e9,
    )
    task.start()

    # wait for the asset to be created
    pytest_gee.wait(task)

    # Do something with the asset name